Binaphthyl compounds as additives in resin compositions

Abstract

The present invention relates to a use of a compound of the formula (I) or a mixture thereof, which are suitable as additives in resin compositions. The compounds are suitable as additives in particular, for thermoplastic resin compositions for producing optical devices such as optical lenses. The present invention also relates to resin compositions containing such binaphthyl compounds and a resin(s). In formula (I), A1 and A2 are identical or different and independently selected from C1- C6-alkylene which are unsubstituted or substituted by 1, 2, 3 or 4 identical or different 0 radicals R'"; X1 and X2 are identical or different and independently selected from the group consisting of O, C(=O), O-C(=O), S and SO2. In formula (I), Ar1, Ar2, R1, R2, L1, L2, k, l, p and q are as defined in the present description.

Description

[0001]M / REUCTR-054-PC 1 Binaphthyl Compounds as additives in resin compositions The present invention relates to binaphthyl compounds, which are suitable as additives in resin compositions, in particular in thermoplastic resin compositions for producing optical devices suchs as optical lenses. The invention also relates to resin compositions containing such binaphthyl compounds and at least one resin, in particular at least one thermoplastic resin. Background of Invention Optical devices, such as optical lenses made of optical resin instead of optical glass are advantageous in that they can be produced in large numbers by injection molding of resin materials, hereinafter referred to as optical resins and optical resin materials, re- spectively. Nowadays, optical resins, in particular, transparent polycarbonate resins, transparent polyester resins and transparent polyestercarbonate resins, are frequently used for producing camera lenses in optical systems of various cameras, such as cameras in smartphones, digital still cameras (DSC), cameras in automotive systems, video cam- eras and the like. In this regard, resins with a high refractive index are highly desira- ble, as they allow for reducing the size and weight of final products. In general, when using an optical material with a higher refractive index, a lens element of the same re- fractive power can be achieved with a surface having less curvature, so that the amount of aberration generated on this surface can be reduced. As a result, it is possi- ble to reduce the number of lenses, to reduce the eccentric sensitivity of lenses and / or to reduce the lens thickness to thereby achieve weight reduction. Moreover, the resin material should have a low or moderate Abbe number to ensure low chromatic aberra- tion. Furthermore, the resins should have excellent heat resistance and high transpar- ency. The production of optical devices such as camera lenses typically requires the molding of the optical resin material used for the production of the optical device. Therefore, the optical resin material must also have a good moldibility. A good moldability typi- cally requires a low melting or softening temperature and a low melt viscosity in order to reduce thermal stress and defects during the molding process. It is difficult to achieve optical resin materials having both good optical properties, such as a high refractive index and a low or moderate Abbe number, and at the same time a good moldability at low temperatures. This is because most of the optical resin materi- als having good optical properties contain a considerable amount of rigid aromatic groups resulting in a high glass transistion temperature (Tg) of the resin material and M / REUCTR-054-PC 2 high melting or softening temperatures and a high melt viscosity at a given tempera- ture. Patent document 1 discloses resin compositions containing an optical bicycloolefine based resin and a monomeric binaphthyl compound having reactive hydroxyl or car- boxyl groups. Patent document 2 discloses resin compositions containing an optical resin based on polycarbonates or polyesters of 9,9-bis (4-(2-hydroxyethoxy) phenyl) fluorene (BPEF) and / or 2,2 ′-bis (2-hydroxyethoxy) -1,1 ′-binaphthalene and an oligomer of 2,2 ′-bis (2-hydroxyethoxy) -1,1 ′-binaphthalene. A particular disadvantage of the technical solutions of patent documents 1 and 2 is that the monomeric or oligomeric compounds still have reactive groups which may result in an undesirable build up of the molecular weight of the resin during the molding pro- cess thereby causing an increase of the melt viscosity which has to be compensated for by higher molding temperatures resuling in an impairment of the moldibility. Patent document 1: EP 3904442 Patent document 2: WO 2021 / 014962 Therefore, there is an ongoing need for providing resin materials having both good op- tical properties, such as high refractive index and low Abbe number, and a good mold- ibiltiy. It was surprisingly found that the compounds of the formula (I) as defined hereinafter reduce the glass transistion temperature (Tg) of resins, in particular of optical thermo- plastic resins without imparting their optical properties. Therefore, a first aspect of the present invention relates to the use of the compound of the formula (I) or a mixture thereof where M / REUCTR-054-PC 3A1 and A2 are identical or different and independently selected from C1-C6-alkylenewhich are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radi- cals R'", X1and X2are identical or different and independently selected from the group con- sisting of O, C(=O), O-C(=O), S and SO2; Ar1is selected from the group consisting of a mono- or polycyclic aryl having from 6 to 50 carbon atoms as ring members and a mono- or polycyclic hetaryl having a total of 5 to 50 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms, where mono- or polycyclic aryl and mono- or polycyclic hetaryl are unsubstituted or carry 1, 2, 3 or 4 radicals RAr; Ar2is selected from the group consisting of a mono- or polycyclic aryl having from 6 to 50 carbon atoms as ring members and a mono- or polycyclic hetaryl having a total of 5 to 50 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms, where mono- or polycyclic aryl and mono- or polycyclic hetaryl are unsubstituted or carry 1, 2, 3 or 4 radicals RAr; L1, L2are identical or different and independently selected from a single bond and C1- C6-alkylene which is unsubstituted or substituted by 1, 2, 3 or 4 identical or dif- ferent radicals R'"; R1and R2are identical or different and independently selected from the group con- sisting of halogen, C1-C20-alkyl, C1-C20-alkoxy, C1-C20-alkyl, C5-C20-cycloalkyl, C6- C20-aryl, C5-C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulphur and oxygen, -C≡C-Rh1, where Rh1 is selected from C6-C20-aryl and C5-C20-hetaryl having 1 or more atoms selected from nitrogen, sulfur and oxygen; C2-C3-alkynyl, CN, R11, OR11, CHsR'3-s, NR112, C(O)R and CH=CHR'', it being possible that R1and R2are identical or different if p+q>1, where s on each occurrence is 0, 1 or 2; k is 0 or 1; l is 0 or 1; p and q are identical or different and independently 0, 1 or 2; M / REUCTR-054-PC 4 RAris selected from the group consisting of CN, R, OR, CHtR'3-t, NR2 and CH=CHR'', where RArmay be identical or different if more than one is present on the same (het)arylene group, where t on each occurrence is 0, 1 or 2; R is selected from the group consisting of C1-C20-alkyl, CN, benzyl, C6-C20-aryl, C5- C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulfur and oxygen, where benzyl, C6-C20-aryl and C5-C20-hetaryl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'", where R is in particular selected from the group consisting of C1-C4-alkyl, CN, phenyl, benzyl, naphthyl, phenanthrenyl and triphenylenyl, where phenyl, benzyl, naphthyl, phenanthrenyl and tri- phenylenyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R11is selected from the group consisting of C1-C20-alkyl, CN, benzyl, C6-C20-aryl, C5- C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulfur and oxygen, where benzyl, C6-C20-aryl and C5-C20-hetaryl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'’’, where R11is in particular selected from the group consisting of C1-C4-alkyl, CN, phenyl, benzyl, naphthyl, phenan- threnyl and triphenylenyl, where phenyl, benzyl, naphthyl, phenanthrenyl and tri- phenylenyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R' is selected from the group consisting of phenyl, naphthyl, phenanthrenyl and tri- phenylenyl, where phenyl, naphthyl, phenanthrenyl and triphenylenyl are unsub- stituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R'' is selected from hydrogen, methyl, phenyl and naphthyl, where phenyl and naph- thyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; and R'" is selected from the group consisting of phenyl, halogen, CN, OCH3, CH3, N(CH3)2 and C(O)CH3, as an additive for resins, in particalar for thermoplastic resins, especially in thermo- plastic resins for producing optical devices. The compounds of the formula (I) are novel, provided that the variables p, q, k, l, Ar1and Ar2meet one or both of the following conditions a), b) orc): a) p+q =1, 2 or 3; b) k+l = 1 or 2; M / REUCTR-054-PC 5 c) k =l = 0, and at least one of Ar1and Ar2are selected from 2-naphthyl, phe- nanthrene-9-yl, 9H-fluoren-2-yl, dibenzo[b,d]thiophen-2-yl, dibenzo[b,d]thio- phen-4-yl, dibenzo[b,d]furan-2-yl, dibenzo[b,d]furan-4-yl, thianthrene-1-yl, thianthrene-2-yl, 2-triphenylenyl and thiophen-3-yl. Therefore, a second aspect of the present invention relates to compounds of the for- mula (I) that are novel. In other words, the second aspect relates to compounds of the formula (I), wherein at least one of the following conditions a), b) or c) are met: a) p+q =1, 2 or 3; b) k+l = 1 or 2; c) k =l = 0, and at least one and in particular both of Ar1and Ar2are selected from 2-naphthyl, phenanthrene-9-yl, 9H-fluoren-2-yl, dibenzo[b,d]thiophen- 2-yl, dibenzo[b,d]thiophen-4-yl, dibenzo[b,d]furan-2-yl, dibenzo[b,d]furan-4- yl, thianthrene-1-yl, thianthrene-2-yl, 2-triphenylenyl and thiophen-3-yl. A third aspect relates to resin compositions comprising at least one resin, such as in particular a thermoplastic resin, especially an optical thermoplastic resin, and at least one compound of the formula (I) as defined herein. The invention further relates to an optical devices made of the resin compositions as defined herein. Detailed Description of Invention: The compounds of formula (I) may have axial chirality due to the limited rotation along the bond between the two naphthyl units of the central 1,1’-binaphthol moiety and therefore compounds of the formula (I) may exist in the form of one of the two enani- omers or in the form of a mixture of these enantiomers. The present invention relates to the pure enatiomers of the compounds of formula (I) and any mixtures of the enan- tiomers, including racemic as well as non-racemic mixtures of these enantiomers. In terms of the present invention, the term "C1-C6-alkylene" may alternatively also be designated "alkandiyl having 1, 2, 3, 4, 5 or 6 carbon atoms" and refers to a bivalent, saturated, aliphatic hydrocarbon radical having 1, 2, 3, 4, 5 or 6 carbon atoms. Exam- ples of C1-C6-alkandiyl are in particular the methylene group (CH2), linear alkylene such as 1,2-ethylene (CH2CH2), 1,3-propylene (CH2CH2CH2), 1,4-butylene (CH2CH2CH2CH2), 1,6-hexylene (CH2CH2CH2CH2CH2CH2), but also branched alkandiyl such as 1-methyl- 1,2-ethylene, 1-methyl-1,2-propylene, 2-methyl-1,2-propylene, 2-methyl-1,3-propyl- ene, 1,3-butylene, 1,3-pentylene and 2-methyl-1,4-pentylene. In terms of the present invention, the term “halogen” refers to fluorine, chlorine, bro- mine or iodine radicals. M / REUCTR-054-PC 6 In terms of the present invention, the term "alkyl" refers to an aliphatic saturated hy- drocarbon radical which may be linear or branched. Examples of C1-C2-alkyl are methyl and ethyl. Examples of C1-C3-alkyl are, in addition to those mentioned for C1-C2-alkyl, n-propyl and isopropyl. Examples of C1-C4-alkyl are, in addition to those mentioned for C1-C3-alkyl, n-butyl, 2-butyl (sec-butyl), isobutyl and tert-butyl. Examples for C1-C6-alkyl are, in addition to those mentioned for C1-C4-alkyl, n-pentyl, 1-methylbutyl, 2-methyl- butyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dime- thylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-tri- methylpropyl, 1-ethyl-1-methylpropyl and 1-ethyl-2-methylpropyl. Examples for C1-C8- alkyl are, in addition to those mentioned for C1-C6-alkyl, n-heptyl, 1-methylhexyl, 2- methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 1-ethylpentyl, 2-ethylpen- tyl, 3-ethylpentyl, n-octyl, 1-methyloctyl, 2-methylheptyl, 1-ethylhexyl, 2-ethylhexyl, 1,2-dimethylhexyl, 1-propylpentyl and 2-propylpentyl. Examples for C1-C10-alkyl are, in addition to those mentioned for C1-C8-alkyl, nonyl, decyl, 2-propylheptyl and 3- propylheptyl. Examples for C1-C18-alkyl are, in addition to those mentioned for C1-C10- alkyl, linear undecyl and its position isomers and branched isomers, lauryl and its posi- tion isomers and branched isomers, linear tridecyl and its position isomers and branched isomers, myristyl and its position isomers and branched isomers, palmityl and its position isomers and branched isomers, and stearyl and its position isomers and branched isomers. Examples for C1-C20-alkyl are, in addition to those mentioned for C1- C18-alkyl, linear nonadecyl and its position isomers and branched isomers and eicosenyl and its position isomers and branched isomers. In terms of the present invention, the term "cycloalkyl" refers to a mono-, bi- or tricy- clic cycloaliphatic radical having from 5 to 20 carbon atoms ("C5-C20-cycloalkyl"), usu- ally from 5 to 10 carbon atoms ("C5-C10-cycloalkyl"), and preferably 5 to 10 carbon at- oms ("C5-C10 cycloalkyl"). Examples of monocyclic C5-C10 cycloalkyl are cyclopentyl, cy- clohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[2.1.1]hexyl, bicy- clo[2.2.1]heptyl, bicyclo[3.1.1]heptyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, bicy- clo[3.2.1]octyl, bicyclo[3.1.0]hexyl, bicyclo[3.2.0]heptyl, bicyclo[3.3.0]octyl (1,2,3,3a,4,5,6,6a-octahydropentalenyl), bicyclo[4.2.0]octyl, bicyclo[4.3.0]nonyl (2,3,3a,4,5,6,7,7a-octahydro-1H-indene) and bicyclo[4.4.0]decyl (decalinyl). In terms of the present invention, the term "alkoxy" refers to a straight-chain or branched alkyl group having from 1 to 20 carbon atoms which is bound to the remain- der of the molecule via an oxygen atom. Examples for C1-C20-alkoxy are methoxy, eth- oxy, n-propoxy, 1-methylethoxy (isopropoxy), butoxy, 1-methylpropoxy (sec-butoxy), 2-methylpropoxy (isobutoxy), 1,1-dimethylethoxy (tert-butoxy), pentoxy, 1-methylbut- oxy, 2-methylbutoxy, 3-methylbutoxy, 1,1-dimethylpropoxy, 1,2-dimethylpropoxy, M / REUCTR-054-PC 7 2,2-dimethylpropoxy, 1-ethylpropoxy, hexoxy, 1-methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1,1-dimethylbutoxy, 1,2-dimethylbutoxy, 1,3-dime- thylbutoxy, 2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dimethylbutoxy, 1-ethylbut- oxy, 2-ethylbutoxy, 1,1,2-trimethylpropoxy, 1,2,2-trimethylpropoxy, 1-ethyl-1- methylpropoxy, 1-ethyl-2-methylpropoxy, heptyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy, tetradecyloxy, pentadecyl, hexadecyloxy, heptadecyloxy, octadecyloxy, nonadecyloxy, eicosyloxy and positional isomers thereof. In terms of the present invention, the term “monocyclic aryl” refers to a monovalent aromatic monocyclic radical, such as in particular phenyl. In terms of the present invention, the term “monocyclic hetaryl” refers to a monovalent heteroaromatic monocyclic radical, i.e. a heteroaromatic monocycle linked by a single covalent bond to the remainder of the molecule, where the ring member atoms are part of a conjugate π-electron system, where the heteroaromatic monocycle has 5 or 6 ring atoms, which comprise as heterocyclic ring members 1, 2, 3 or 4 nitrogen atoms or 1 oxygen atom and 0, 1, 2 or 3 nitrogen atoms, or 1 sulphur atom and 0, 1, 2 or 3 nitrogen atoms, where the remaining ring atoms are carbon atoms. Examples include furyl (= furanyl), pyrrolyl (= 1H-pyrrolyl), thienyl (= thiophenyl), imidazolyl (= 1H-im- idazolyl), pyrazolyl (= 1H-pyrazolyl), 1,2,3-triazolyl, 1,2,4-triazolyl, tetrazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, 1,3,4-oxadiazolyl, 1,3,4-thiadiazolyl, pyridyl (= pyridi- nyl), pyrazinyl, pyridazinyl, pyrimidinyl and triazinyl. In terms of the present invention, the term “mono- or polycyclic aryl” refers to a mono- valent aromatic monocyclic radical as defined herein or to a monovalent aromatic poly- cyclic radical, i.e. a polycyclic arene linked by a single covalent bond to the remainder of the molecule, where the polycyclic arene is (i) an aromatic polycyclic hydrocarbon, i.e. a completely unsaturated polycyclic hydro- carbon, where each of the carbon atoms is part of a conjugate π-electron system, (ii) a polycyclic hydrocarbon which bears at least 1 phenyl ring which is fused to a sat- urated or unsaturated 4 to 10-membered mono- or bicyclic hydrocarbon ring, (iii) a polycyclic hydrocarbon which bears at least 2 phenyl rings which are linked to each other by a covalent bond or which are fused to each other directly and / or which are fused to a saturated or unsaturated 4 to 10-membered mono- or bicyclic hydrocar- bon ring, (iv) a polycyclic hydrocarbon which bears at least 2 phenyl rings which are linked to each other by a methylene bridge, where the methylene bridge may be unsubstituted or carry one or two substitutents selected from C1-C4-methyl, phenyl, naphthyl and phenanthrenyl and where the methylene bridge may part of a spirobicyclic carbocycle, where each carbocycle comprise at least one fused benzene ring. M / REUCTR-054-PC 8 Mono- or polycyclic aryl has from 6 to 50, often from 6 to 40 carbon atoms, e.g. 6, 9, 10, 12, 13, 14, 16, 17, 18, 19, 20, 22, 24, 26, 30, 33 or 40 carbon atoms as ring at- oms, in particular from 6 to 26 carbon atoms, especially 6, 10, 12, 13, 14, 16, 17, 18, 19, 20, 22, 24 or 26 carbon atoms. Polycyclic aryl typically has 10 to 50 carbon atoms as ring atoms, in particular from 10 to 40 carbon atoms, especially 10, 12, 13, 14, 16, 17, 18, 19, 20, 22, 24, 26, 30, 33 or 40 carbon atoms. In this context, polycyclic aryl bearing 2, 3 or 4 phenyl rings which are linked to each other via a single bond include e.g. biphenylyl and terphenylyl. Polycyclic aryl bearing 2, 3 or 4 phenyl rings which are directly fused to each other include e.g. naphthyl, an- thracenyl, phenanthrenyl, pyrenyl, triphenylenyl, chrysenyl and benzo[c]phenanthrenyl. Polycyclic aryl bearing 2, 3 or 4 phenyl rings which are fused to a saturated or unsatu- rated 4- to 10-membered mono- or bicyclic hydrocarbon ring include e.g. 9H-fluorenyl, biphenylenyl, tetraphenylenyl, acenaphthenyl (1,2-dihydroacenaphthylenyl), acenaph- thylenyl, 9,10-dihydroanthracen-1-yl, 1,2,3,4-tetrahydrophenanthrenyl, 5,6,7,8-tetrahy- drophenanthrenyl, cyclopent[fg]acenaphthylenyl, phenalenyl, fluoranthenyl, benzo[k]fluoranthenyl, perylenyl, 9,10-dihydro-9,10[1',2']-benzenoanthracenyl, dibenzo[a,e][8]annulenyl, 9,9'-spirobi[9H-fluoren]yl and spiro[1H-cyclobuta[de]naph- thalene-1,9'-[9H]fluoren]yl. Mono- or polycylic aryl includes, by way of example phenyl, naphthyl, 9H-fluorenyl, phenanthrenyl, anthracenyl, pyrenyl, chrysenyl, benzo[c]phenanthrenyl, acenaph- thenyl, acenaphthylenyl, 2,3-dihydro-1H-indenyl, 5,6,7,8-tetrahydro-naphthalenyl, cy- clopent[fg]acenaphthylenyl, 2,3-dihydrophenalenyl, 9,10-dihydroanthracen-1-yl, 1,2,3,4-tetrahydrophenanthrenyl, 5,6,7,8-tetrahydrophenanthrenyl, fluoranthenyl, benzo[k]fluoranthenyl, biphenylenyl, triphenylenyl, tetraphenylenyl, 1,2-dihydroace- naphthylenyl, dibenzo[a,e][8]annulenyl, perylenyl, biphenylyl, terphenylyl, naph- thylenphenyl, phenanthrenylphenyl, anthracenylphenyl, pyrenylphenyl, 9H-fluorenyl- phenyl, di(naphthylen)phenyl, naphthylenbiphenyl, tri(phenyl)phenyl, tetra(phenyl)phe- nyl, pentaphenyl(phenyl), phenylnaphthyl, binaphthyl, biphenanthrenyl, phenan- threnylnaphthyl, pyrenylnaphthyl, phenylanthracenyl, biphenylanthracenyl, naphtha- lenylanthracenyl, phenanthrenylanthracenyl, 9,10-dihydro-9,10[1’,2’]benzoanthracenyl, 9,9’-spirobi-9H-fluorenyl and spiro[1H-cyclobuta[de]naphthalene-1,9'-[9H]fluoren]yl. In terms of the present invention, the term “mono- or polycyclic hetaryl” refers to a monovalent heteroaromatic monocyclic radical as defined herein or to a monovalent heteroaromatic polycyclic radical, i.e. a polycyclic hetarene linked by a single covalent bond to the remainder of the molecule, where (i) the polycyclic hetarene bears a heteroaromatic monocycle as defined above and at least one, e.g. 1, 2, 3, 4 or 5, further aromatic rings selected from phenyl and het- eroaromatic monocycles as defined above, where the aromatic rings of the polycyclic M / REUCTR-054-PC 9 hetarene are linked to each other by a covalent bond and / or fused to each other di- rectly and / or fused to a saturated or unsaturated 4 to 10-membered mono- or bicyclic hydrocarbon ring, or (ii) the polycyclic hetarene bears at least one saturated or partially or fully unsaturated 5-, 6-, 7- or 8-membered heterocyclic ring bearing 1, 2 or 3 heteroatoms selected from oxygen, sulphur and nitrogen as ring atoms, such as 2H-pyran, 4H-pyran, thiopyran, 1,4-dihydropyridin, 4H-1,4-oxazin, 4H-1,4-thiazin, 1,4-dioxin, oxepin, thiepin, dioxin, dithiin, dioxepin, dithiepin, dioxocine, dithiocine and at least one, e.g. 1, 2, 3, 4 or 5, aromatic rings selected from phenyl and heteroaromatic monocycles as defined above, where at least one of the aromatic rings is directly fused to the saturated or partially unsaturated 5- to 8-membered heterocyclic ring and where the aromatic rings of the polycyclic hetarene are linked to each other by a covalent bond or fused to each other directly and / or fused to a saturated or unsaturated 4 to 10-membered mono- or bicy- clic hydrocarbon ring, or (iii) the polycyclic hetarene bears at least two moncyclic aromatic rings selected from phenyl and heteroaromatic monocycles as defined above, where the two rings are linked to each other by a heteroatom selected from oxygen, sulphur and nitrogen, and are in particular linked by O, S, NRH, SO and SO2, where RH is hydrogen, C1-C4-alkyl, phenyl, naphthyl or phenanthrenyl. Mono- or polycyclic hetaryl has from 5 to 50, often from 5 to 40 or 5 to 34 ring atoms, in particular 5 to 26 ring atoms, which comprise 1, 2, 3 or 4 atoms selected from nitro- gen atoms, sulphur atoms and oxygen atoms, where the remainder of the ring atoms are carbon atoms. Polycyclic hetaryl generally has from 9 to 50, often from 9 to 34 ring atoms, in particular 9 to 26 ring atoms, which comprise 1, 2, 3 or 4 atoms selected from nitrogen atoms, sulphur atoms and oxygen atoms, where the remainder of the ring atoms are carbon atoms. Examples of polycyclic hetaryl include, but are not limited to, benzofuryl, benzothienyl, dibenzofuranyl (= dibenzo[b,d]furanyl), dibenzothienyl (= dibenzo[b,d]thienyl), naphthofuryl, naphthothienyl, furo[3,2-b]furanyl, furo[2,3-b]furanyl, furo[3,4-b]furanyl, thieno[3,2-b]thienyl, thieno[2,3-b]thienyl, thieno[3,4-b]thienyl, oxanthrenyl, thi- anthrenyl, indolyl (= 1H-indolyl), isoindolyl (= 2H-isoindolyl), carbazolyl, indolizinyl, benzopyrazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzo[c,d]indolyl, 1H- benzo[g]indolyl, quinolinyl, isoquinolinyl, acridinyl, phenazinyl, quinazolinyl, quinoxali- nyl, phenoxazinyl, phenthiazinyl, benzo[b][1,5]naphthyridinyl, cinnolinyl, 1,5-naphthy- ridinyl, 1,8-naphthyridinyl, phenylpyrrolyl, naphthylpyrrolyl, dipyridyl, phenylpyridyl, naphthylpyridyl, pyrido[4,3-b]indolyl, pyrido[3,2-b]indolyl, pyrido[3,2-g]quinolinyl, pyr- ido[2,3-b][1,8]naphthyridinyl, pyrrolo[3,2-b]pyridinyl, pteridinyl, puryl, 9H-xanthenyl, 9H-thioxanthenyl, 2H-chromenyl, 2H-thiochromenyl, phenanthridinyl, phenanthrolinyl, benzo[1,2-b:4,3-b’ ]difuranyl, benzo[1,2-b:6,5-b’ ]difuranyl, benzo[1,2-b:5,4-b’ ]di- furanyl, benzo[1,2-b:4,5-b’ ]difuranyl, naphthofuranyl, benzo[b]naphtho[1,2-d]furanyl, M / REUCTR-054-PC 10 benzo[b]naphtho[2,3-d]furanyl, benzo[b]naphtho[2,1-d]furanyl, tribenzo[b,d,f ]ox- epinyl, dibenzo[b,d]thienyl, naphtho[1,2-b]thienyl, naphtho[2,3-b]thienyl, naphtho[2,1- b]thienyl, benzo[b]naphtho[1,2-d]thienyl, benzo[b]naphtho[2,3-d]thienyl, benzo[b]naphtho[2,1-d]thienyl, 6H-dibenzo[b,d]thiopyranyl, 5H,9H-[1]benzothiopy- rano[5,4,3-c,d,e][2]benzothiopyranyl, 5H,10H-[1]benzothiopyrano[5,4,3-c,d,e][2]ben- zothiopyranyl, benzo[1,2-b:4,3-b' ]bisthienyl, benzo[1,2-b:6,5-b' ]bisthienyl, benzo[1,2- b:5,4-b' ]bisthienyl, benzo[1,2-b:4,5-b' ]bisthienyl, 1,4-benzodithiinyl, naphtho[1,2- b][1,4]dithiinyl, naphtho[2,3-b][1,4]dithiinyl, thianthrenyl, benzo[a]thianthrenyl, benzo[b]thianthrenyl, dibenzo[a,c]thianthrenyl, dibenzo[a,h]thianthrenyl, dibenzo[a,i ]thianthrenyl, dibenzo[a,j ]thianthrenyl, dibenzo[b,i ]thianthrenyl, 2H-naph- tho[1,8-b,c]thienyl, 5H-phenanthro[4,5-b,c,d]thiopyranyl, 10,11-dihydrodi- benzo[b,f ]thiepinyl, 6,7-dihydrodibenzo[b,d]thiepinyl, dibenzo[b,f ]thiepinyl, dibenzo[b,d]thiepinyl, 6H-dibenzo[d,f ][1,3]dithiepinyl, tribenzo[b,d,f ]thiepinyl, ben- zothieno[3,4-c,d]thieno[2,3,4-j,k][2]benzothiepinyl, dinaphtho[1,8-b;c:1',8'-f,g][1,5]di- thiocinyl, furo[3,2-g]quinolinyl, furo[2,3-g]quinolinyl, furo[2,3-g]quinoxalinyl, benzo[g]chromenyl, thieno[3,2-f ][1]benzothienyl, thieno[2,3-f ][1]benzothienyl, thieno[3,2-g]quinolinyl, thieno[2,3-g]quinolinyl, thieno[2,3-g]quinoxalinyl, benzo[g]thi- ochromenyl, pyrrolo[3,2,1-h,i ]indolyl, benzo[g]quinoxalinyl, benzo[f ]quinoxalinyl, benzo[h]isoquinolinyl, 14H-dibenzo[a,j]-xanthenyl, spiro[fluorene-9,9'-xanthen]-yl, spi- robi(xanthen)-yl, spiro[thioxanthene-9,9'-xanthen]-yl, and spiro[dibenzo[c,h]xanthene- 7,9'-fluoren]-yl. In terms of the present invention, the term “monocyclic arylene” refers to a bivalent aromatic monocyclic radical, such as in particular phenylene. In terms of the present invention, the term “monocyclic hetarylene” refers to a bivalent heteroaromatic monocyclic radical, i.e. a heteroaromatic monocycle linked by two sin- gle covalent bonds to the two remaining parts of the molecule, where the ring member atoms are part of a conjugate π-electron system, where the heteroaromatic monocycle has 5 or 6 ring atoms, which comprise as heterocyclic ring members 1, 2, 3 or 4 nitro- gen atoms or 1 oxygen atom and 0, 1, 2 or 3 nitrogen atoms, or 1 sulphur atom and 0, 1, 2 or 3 nitrogen atoms, where the remaining ring atoms are carbon atoms. Examples include furylene (= furanylene), pyrrolylene (= 1H-pyrrolylene), thienylene (= thio- phenylene), imidazolylene (= 1H-imidazolylene), pyrazolylene (= 1H-pyrazolylene), 1,2,3-triazolylene, 1,2,4-triazolylene, tetrazolylene, oxazolylene, thiazolylene, isoxazol- ylene, isothiazolylene, 1,3,4-oxadiazolylene, 1,3,4-thiadiazolylene, pyridylene (= pyridi- nylene), pyrazinylene, pyridazinylene, pyrimidinylene and triazinylene. In terms of the present invention, the term “mono- or polycyclic arylene” refers to a bi- valent aromatic monocyclic radical as defined herein or to a bivalent aromatic polycy- clic radical, i.e. a polycyclic arene linked by two single covalent bonds to the two re- maining parts of the molecule, where the polycyclic arene is M / REUCTR-054-PC 11 (i) an aromatic polycyclic hydrocarbon, i.e. a completely unsaturated polycyclic hydro- carbon, where each of the carbon atoms is part of a conjugate π-electron system, (ii) a polycyclic hydrocarbon which bears at least 1 phenyl ring which is fused to a sat- urated or unsaturated 4 to 10-membered mono- or bicyclic hydrocarbon ring, (iii) a polycyclic hydrocarbon which bears at least 2 phenyl rings which are linked to each other by a covalent bond or which are fused to each other directly and / or which are fused to a saturated or unsaturated 4 to 10-membered mono- or bicyclic hydrocar- bon ring, (iv) a polycyclic hydrocarbon which bears at least 2 phenyl rings which are linked to each other by a methylene bridge, where the methylene bridge may be unsubstituted or carry one or two substitutents selected from C1-C4-methyl, phenyl, naphthyl and phenanthrenyl and where the methylene bridge may part of a spirobicyclic carbocycle, where each carbocycle comprise at least one fused benzene ring. Mono- or polycyclic arylene has from 6 to 26, often from 6 to 24 carbon atoms, e.g. 6, 9, 10, 12, 13, 14, 16, 17, 18, 19, 20, 22 or 24 carbon atoms as ring atoms, in particu- lar from 6 to 20 carbon atoms, especially 6, 10, 12, 13, 14, 16, 17 or 18 carbon atoms. Polycyclic arylene typically has 10 to 26 carbon atoms as ring atoms, in particular from 10 to 20 carbon atoms, especially 10, 12, 13, 14, 16, 17 or 18 carbon atoms. In this context, polycyclic arylene bearing 2, 3 or 4 phenyl rings which are linked to each other via a single bond include e.g. biphenylylene and terphenylylene. Polycyclic arylene bearing 2, 3 or 4 phenyl rings which are directly fused to each other include e.g. naphthylene, anthracenylene, phenanthrenylene, pyrenylene, triphenylenylene, chrysenylene and benzo[c]phenanthrenylene. Polycyclic arylene bearing 2, 3 or 4 phe- nyl rings which are fused to a saturated or unsaturated 4- to 10-membered mono- or bicyclic hydrocarbon ring include e.g. 9H-fluorenylene, biphenylenylene, tetra- phenylenylene, acenaphthenylene (1,2-dihydroacenaphthylenylene), acenaph- thylenylene, 9,10-dihydroanthracen-1-ylene, 1,2,3,4-tetrahydrophenanthrenylene, 5,6,7,8-tetrahydrophenanthrenylene, cyclopent[fg]acenaphthylenylene, phenalenylene, fluoranthenylene, benzo[k]fluoranthenylene, perylenylene, 9,10-dihydro-9,10[1',2']- benzenoanthracenylene, dibenzo[a,e][8]annulenylene, 9,9'-spirobi[9H-fluoren]ylene and spiro[1H-cyclobuta[de]naphthalene-1,9'-[9H]fluoren]ylene. Mono- or polycylic arylene includes, by way of example phenylene, naphthylene, 9H- fluorenylene, phenanthrenylene (= phenanthrendiyl), anthracenylene, pyrenylene, chrysenylene, benzo[c]phenanthrenylene, acenaphthenylene, acenaphthylenylene, 2,3- dihydro-1H-indenylene, 5,6,7,8-tetrahydro-naphthalenylene, cyclopent[fg]acenaph- thylenylene, 2,3-dihydrophenalenylene, 9,10-dihydroanthracen-1-ylene, 1,2,3,4-tetra- hydrophenanthrenylene, 5,6,7,8-tetrahydrophenanthrenylene, fluoranthenylene, benzo[k]fluoranthenylene, biphenylenylene, triphenylenylene, tetraphenylenylene, 1,2- dihydroacenaphthylenylene, dibenzo[a,e][8]annulenylene, perylenylene, biphenylylene, M / REUCTR-054-PC 12 propane-2,2-diylbisphenylene, terphenylylene, naphthylenphenylene, phenan- threnylphenylene, anthracenylphenylene, pyrenylphenylene, 9H-fluorenylphenylene, di(naphthylen)phenylene, naphthylenbiphenylene, tri(phenyl)phenylene, tetra(phe- nyl)phenylene, pentaphenyl(phenylene), phenylnaphthylene, binaphthylene, biphenan- threnylene, phenanthrenylnaphthylene, pyrenylnaphthylene, phenylanthracenylene, bi- phenylanthracenylene, naphthalenylanthracenylene, phenanthrenylanthracenylene, phenylmethylenebis(naphthalenediyl), naphthalene-1-yl-methylenebis(naphtha- lenediyl), naphthalene-2-yl-methylenebis(naphthalenediyl), 9H-fluorene-9,9- diylbis(phenylene), 9H-fluorene-9,9-diylbis(1,1'-biphenylylene), 9H-fluorene-9,9- diylbis(naphthylene), dibenzo[a,e][8]annulenylene, 9,10-dihydro-9,10[1’,2’]benzo- anthracenylene, 9,9’-spirobi-9H-fluorenylene and spiro[1H-cyclobuta[de]naphthalene- 1,9'-[9H]fluoren]ylene. In terms of the present invention, the term “mono- or polycyclic hetarylene” refers to a bivalent heteroaromatic monocyclic radical as defined herein or to a bivalent heteroaro- matic polycyclic radical, i.e. a polycyclic hetarene linked by two single covalent bonds to the two remaining parts of the molecule, where (i) the polycyclic hetarene bears a heteroaromatic monocycle as defined above and at least one, e.g. 1, 2, 3, 4 or 5, further aromatic rings selected from phenyl and het- eroaromatic monocycles as defined above, where the aromatic rings of the polycyclic hetarene are linked to each other by a covalent bond and / or fused to each other di- rectly and / or fused to a saturated or unsaturated 4 to 10-membered mono- or bicyclic hydrocarbon ring, or (ii) the polycyclic hetarene bears at least one saturated or partially or fully unsaturated 5-, 6-, 7- or 8-membered heterocyclic ring bearing 1, 2 or 3 heteroatoms selected from oxygen, sulphur and nitrogen as ring atoms, such as 2H-pyran, 4H-pyran, thiopyran, 1,4-dihydropyridin, 4H-1,4-oxazin, 4H-1,4-thiazin, 1,4-dioxin, oxepin, thiepin, dioxin, dithiin, dioxepin, dithiepin, dioxocine, dithiocine and at least one, e.g. 1, 2, 3, 4 or 5, aromatic rings selected from phenyl and heteroaromatic monocycles as defined above, where at least one of the aromatic rings is directly fused to the saturated or partially unsaturated 5- to 8-membered heterocyclic ring and where the aromatic rings of the polycyclic hetarene are linked to each other by a covalent bond or fused to each other directly and / or fused to a saturated or unsaturated 4 to 10-membered mono- or bicy- clic hydrocarbon ring, or (iii) the polycyclic hetarene bears at least two moncyclic aromatic rings selected from phenyl and heteroaromatic monocycles as defined above, where the two rings are linked to each other by a heteroatom selected from oxygen, sulphur and nitrogen, and are in particular linked by O, S, NRH, SO and SO2, where RHis hydrogen, C1-C4-alkyl, phenyl, naphthyl or phenanthrenyl. M / REUCTR-054-PC 13 Mono- or polycyclic hetarylene has from 5 to 26, often from 5 to 24 ring atoms, in par- ticular 5 to 20 ring atoms, which comprise 1, 2, 3 or 4 atoms selected from nitrogen at- oms, sulphur atoms and oxygen atoms, where the remainder of the ring atoms are carbon atoms. Polycyclic hetaryl generally has from 9 to 26, often from 9 to 24 ring at- oms, in particular 9 to 20 ring atoms, which comprise 1, 2, 3 or 4 atoms selected from nitrogen atoms, sulphur atoms and oxygen atoms, where the remainder of the ring at- oms are carbon atoms. Examples of polycyclic hetarylene include, but are not limited to, benzofurylene, ben- zothienylene, dibenzofuranylene (= dibenzo[b,d]furanylene), dibenzothienylene (= dibenzo[b,d]thienylene), naphthofurylene, naphthothienylene, furo[3,2-b]furanylene, furo[2,3-b]furanylene, furo[3,4-b]furanylene, thieno[3,2-b]thienylene, thieno[2,3- b]thienylene, thieno[3,4-b]thienylene, oxanthrenylene, thianthrenylene, indolylene (= 1H-indolylene), isoindolylene (= 2H-isoindolylene), carbazolylene, indolizinylene, benzopyrazolylene, benzimidazolylene, benzoxazolylene, benzothiazolylene, benzo[c,d]indolylene, 1H-benzo[g]indolylene, quinolinylene, isoquinolinylene, acri- dinylene, phenazinylene, quinazolinylene, quinoxalinylene, phenoxazinylene, phenthia- zinylene, benzo[b][1,5]naphthyridinylene, cinnolinylene, 1,5-naphthyridinylene, 1,8- naphthyridinylene, phenylpyrrolylene, naphthylpyrrolylene, dipyridylene, phenylpyri- dylene, naphthylpyridylene, pyrido[4,3-b]indolylene, pyrido[3,2-b]indolylene, pyr- ido[3,2-g]quinolinylene, pyrido[2,3-b][1,8]naphthyridinylene, pyrrolo[3,2-b]pyridi- nylene, pteridinylene, purylene, 9H-xanthenylene, 9H-thioxanthenylene, 2H-chrome- nylene, 2H-thiochromenylene, phenanthridinylene, phenanthrolinylene, benzo[1,2- b:4,3-b’ ]difuranylene, benzo[1,2-b:6,5-b’ ]difuranylene, benzo[1,2-b:5,4-b’ ]di- furanylene, benzo[1,2-b:4,5-b’ ]difuranylene, naphthofuranylene, benzo[b]naph- tho[1,2-d]furanylene, benzo[b]naphtho[2,3-d]furanylene, benzo[b]naphtho[2,1- d]furanylene, tribenzo[b,d,f ]oxepinylene, dibenzo[b,d]thienylene, naphtho[1,2- b]thienylene, naphtho[2,3-b]thienylene, naphtho[2,1-b]thienylene, benzo[b]naph- tho[1,2-d]thienylene, benzo[b]naphtho[2,3-d]thienylene, benzo[b]naphtho[2,1- d]thienylene, 6H-dibenzo[b,d]thiopyranylene, 5H,9H-[1]benzothiopyrano[5,4,3- c,d,e][2]benzothiopyranylene, 5H,10H-[1]benzothiopyrano[5,4,3-c,d,e][2]benzothiopy- ranylene, benzo[1,2-b:4,3-b' ]bisthienylene, benzo[1,2-b:6,5-b' ]bisthienylene, benzo[1,2-b:5,4-b' ]bisthienylene, benzo[1,2-b:4,5-b' ]bisthienylene, 1,4-benzodithi- inylene, naphtho[1,2-b][1,4]dithiinylene, naphtho[2,3-b][1,4]dithiinylene, oxybi- sphenylene, sulfonylbisphenylene, sulfinylbisphenylene, sulfanylbisphenylene, thi- anthrenylene, benzo[a]thianthrenylene, benzo[b]thianthrenylene, dibenzo[a,c]thi- anthrenylene, dibenzo[a,h]thianthrenylene, dibenzo[a,i ]thianthrenylene, dibenzo[a,j ]thianthrenylene, dibenzo[b,i ]thianthrenylene, 2H-naphtho[1,8- b,c]thienylene, 5H-phenanthro[4,5-b,c,d]thiopyranylene, 10,11-dihydrodi- benzo[b,f ]thiepinylene, 6,7-dihydrodibenzo[b,d]thiepinylene, dibenzo[b,f ]thiepinylene, dibenzo[b,d]thiepinylene, 6H-dibenzo[d,f ][1,3]dithi- M / REUCTR-054-PC 14 epinylene, tribenzo[b,d,f ]thiepinylene, benzothieno[3,4-c,d]thieno[2,3,4-j,k][2]ben- zothiepinylene, dinaphtho[1,8-bc:1',8'-f,g][1,5]dithiocinylene, furo[3,2-g]quinolinylene, furo[2,3-g]quinolinylene, furo[2,3-g]quinoxalinylene, benzo[g]chromenylene, thieno[3,2-f ][1]benzothienylene, thieno[2,3-f ][1]benzothienylene, thieno[3,2-g]quino- linylene, thieno[2,3-g]quinolinylene, thieno[2,3-g]quinoxalinylene, benzo[g]thio- chromenylene, pyrrolo[3,2,1-h,i ]indolylene, benzo[g]quinoxalinylene, benzo[f ]quinox- alinylene, benzo[h]isoquinolinylene, 14H-dibenzo[a,j]-xanthenediyl, spiro[fluorene-9,9'- xanthene]diyl, spirobi(xanthen)diyl, spiro[thioxanthene-9,9'-xanthene]diyl, and spiro[dibenzo[c,h]xanthene-7,9'-fluorene]diyl. In terms of the present invention, the suffix “-ylene” means, as customary in the art, that the respective het(arene) moiety is in the form of its diradikal. Accordingly, the suffix “-ylene”, as e.g. in phenylene or 1,4-phenylene, is used here synonymously with the the suffix “-diyl”, as e.g. in phendiyl or phen-1,4-diyl. In terms of the present invention, a “structural unit” is a structural element which is present repeatedly in the polymer backbone of the thermoplastic resin. Therefore, the terms “structural unit” and “repeating unit” are used synonymously. In terms of the present invention, the term “optical device” refers to a device that is transparent for visible light and manipulates light beams, in particular by refraction. Optical devices include but are not limited to prisms, lenses, optical films and combina- tions thereof, especially lenses for cameras and lenses for glasses. The remarks made below as to preferred embodiments of the variables (substituents) of the compounds of formulae (I), (Ia) and (Ib) are valid on their own as well as pref- erably in combination with each other. The remarks made below concerning preferred embodiments of the variables further are valid on their own as well as preferably in combination with each other concerning the compounds of formula (I) and the structural units of formulae (II-1), (II-2) and (II- 3), where applicable, as well as concerning the resin compositions and uses according to the invention. Preference is given to the compound of formula (I) and to the use thereof, where the formula (I) is represented by the formula (Ia): M / REUCTR-054-PC 15 wherein the variables A1, A2, X1, X2, Ar1, Ar2, L1, L2, R1, R2, k, l, p and q have the mean- ings defined herein, in particular have the meanings mentioned herein as preferred. In formulae (I) and (Ia) the variables A1, A2, X1, X2, Ar1, Ar2, L1, L2, R1, R2, k, l, p and q on their own or preferably in any combination preferably have the following meanings: The variables A1and A2in formulae (I) and (Ia) are identical or different and independently selected from C1-C6-alkylene, preferably C1-C4-alkylene, which are unsubstituted or substituted by 1, 2, 3 or 4, preferably by 1 or 2, identical or different radicals R'", where R'" in each occurance has one of the meanings defined herein, in particular one of those mentioned herein as preferred. In a particular group (1) of embodiments, the variables A1and A2in formulae (I) and (Ia) are independently selected from linear C2-C4-alkandiyl, such as 1,2-ethandiyl (CH2- CH2), 1,3-propandiyl or 1,4-butandiyl, and in particular 1,2-ethandiyl. In this context it is particularly preferred that the variables A1and A2are identical to each other. In a preferred subgroup (1.1) of group (1) of embodiments the variables A1and A2in formulae (I) and (Ia) are both -CH2-CH2-. In a particular group (2) of embodiments, the moieties X1and X2in formulae (I) and (Ia) are selected from O, C(=O), S and SO2, and are preferably identical to each other. In a preferred subgroup (2.1) of group (2) of embodiments the moieties X1and X2in formulae (I) and (Ia) are both O. Preference is given to the variables Ar1and Ar2in formulae (I) and (Ia) that are inde- pendently is selected from mono- or polycyclic aryl having from 6 to 36, especially from 6 to 26, carbon atoms as ring members and mono- or polycyclic hetaryl having from 5 to 36, especially from 5 to 26, ring atoms, which comprise 1, 2, 3 or 4 atoms, in particular 1, 2 or 3 atoms, specifically 1 or 2 atoms, selected from nitrogen atoms, sul- fur atoms and oxygen atoms, where the remainder of the ring atoms are carbon at- M / REUCTR-054-PC 16 oms, where the mono- or polycyclic aryl and the mono- or polycyclic hetaryl are unsub- stituted or carry 1, 2 or 3 radicals RAr; wherein RArhave the meanings defined herein, in particular those mentioned herein as preferred. In a particular group (3) of embodiments the variables Ar1and Ar2are independently from each other selected from mono-or polycyclic aryl having from 6 to 36, preferably 6 to 26, in particular 6 to 20, carbon atoms as ring members, where Ar1and Ar2are in- dependently unsubstituted or carry 1, 2 or 3, preferably 1 or 2, in particular 1, substit- uents RAr, wherein RArin each occurance has the meaning defined herein, in particular one mentioned herein as preferred. In an preferred subgroup (3.1) of group (3) of embodiments, the variable Ar1is phe- nyl, naphthyl or phenanthrenyl, where phenyl, naphthyl and phenanthrenyl are unsub- stituted or substituted by 1, 2, 3 or 4, preferably 1 or 2, in particular 1, identical or dif- ferent radicals R'"; or Ar1is a group represented by the following formula (Ar1-a): (Ar1-a), where # represents a connection point to L1, a and b are identical or different and independently 0 or 1, and RAr1and RAr2are identical or different and have the meanings defined herein for RAr, in particular the preferred meanings. In the context of this subgroup (3.1) of embodiments, the one or more radicals R'", if present, are preferably selected from phenyl, halogen, CN, CH3 and OCH3, especially from halogen and CN, while the variable b in formula (Ar1-a) is preferably 0. In an preferred subgroup (3.2) of group (3) of embodiments, the variable Ar2is phe- nyl, naphthyl or phenanthrenyl, where phenyl, naphthyl and phenanthrenyl are unsub- stituted or substituted by 1, 2, 3 or 4, preferably 1 or 2, in particular 1, identical or dif- ferent radicals R'"; or Ar2is a group represented by the following formula (Ar2-a): M / REUCTR-054-PC 17 (Ar2-a), where # represents a connection point to L2, a and b are identical or different and independently 0 or 1, and RAr1and RAr2are identical or different and have the meanings defined herein for RAr, in particular the preferred meanings. In the context of this subgroup (3.2) of embodiments, the one or more radicals R'", if present, are preferably selected from phenyl, halogen, CN, CH3 and OCH3, especially from halogen and CN, while the variable b in formula (Ar1-a) is preferably 0. In a particularly preferred subgroup (3’) of subgroups (3.1) and (3.2) of embodiments, the variables Ar1and Ar2are identical, i.e. are both either phenyl, naphthyl, phenan- threnyl or identical radicals (Ar1-a) and (Ar2-a), where phenyl, naphthyl and phenan- threnyl are optionally substituted and, if substituted, are preferably intendically substi- tuted, i.e. bearing one or two radicals R'" which between the groups Ar1and Ar2have the same meanings and are located in the same positions. In this context the radicals R'", if present, have the meanings defined herein, in particular the preferred meanings. In a particularly preferred subgroup (3’’) of subgroups (3.1) and (3.2) of embodiments, the variable Ar1is a radical of formula (Ar1-a) and the variable Ar2is an optionally sub- stituted phenyl, naphthyl or phenanthrenyl, where phenyl, naphthyl and phenan- threnyl, if substituted, preferably carry one or two radicals R'", which have the mean- ings defined herein, in particular the preferred meanings. If phenyl, naphthyl or phe- nanthrenyl are substituted with two radicals R'", they may be different or are prefera- bly identical. In a particular group (4) of embodiments the one or more radicals RArin formulae (I) and (Ia) are selected from the group consisting of R, OR and NR2, especially R and OR, where RArmay be identical or different if more than one RAris present on the same (het)aryl group. In this context R has one of the meanings defined herein and is in par- ticular selected from the group consisting of methyl, ethyl, phenyl, benzyl, naphthyl, such as 1-naphthyl or 2-naphthyl, and phenanthrenyl, such as 9-phenanthrenyl, in par- M / REUCTR-054-PC 18 ticular from phenyl, benzyl and naphthyl, where R may be substituted with 1 or 2 radi- cals R'" and preferably is unsubstituted. Accordingly, in this group (4) of embodiments, the one or more radicals RArare preferably selected from the group consisting of C1-C4- alkyl, phenyl, benzyl, naphthyl, phenanthrenyl, C1-C4-alkoxy, phenoxy, benzyloxy, naphthyloxy, phenanthrenyloxy, di(C1-C4-alkyl)amino, diphenylamino, dibenzylamino and dinaphthylamino, diphenanthrenylamino, and especially from the group consisting of phenyl, benzyl, naphthyl, phenoxy, benzyloxy and naphthyloxy. In a particular group (5) of embodiments the two moieties L1and L2are identical or different and are independently selected from the group consisting of a single bond and C1-C4-alkylene, such as in particular linear C1-C4-alkylene. More preference is given here to moieties L1and L2that are independently selected from a single bond, meth- ylene (CH2), 1,2-ethylene (CH2CH2), 1,3-propylene (CH2CH2CH2), in particular from a single bond and methylene. In a particular subgroup (5’) of group (5) of embodiments, the two moieties L1and L2are identical and preferably are both a single bond, methylene (CH2), 1,2-ethylene (CH2CH2) or 1,3-propylene, and more preferably are both a single bond or methylene. In a particular subgroup (5’’) of group (5) of embodiments, the sum k+l of the varia- bles k and l in formulae (I) and (Ia) is 1 or 2 and both moieties L1and L2are single bonds, or the sum k+l is 0 and both moieties L1and L2are single bonds, methylene or mixtures thereof. In a particular group (6) of embodiments the radicals R1and R2of formulae (I) and (Ia), if present, are independently selected from the group consisting of halogen, C2- C3-alkynyl, CN, R11and OR11, where R11is in particular selected from the group consist- ing of benzyl, mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms or are mono- or polycyclic hetaryl having a total of 5 to 18 atoms, which are ring mem- bers, where 1, 2, 3 or 4, in particular 1 or 2, of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms, where aryl and hetaryl are unsubstituted or carry a substituent R'". In a preferred subgroup (6.1) of group (6) of embodiments the radicals R1and R2, if present, are independently selected from the group consisting of halogen, C2-C3-al- kynyl, CN, R11and OR11, where R11is selected from benzyl and mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms and mono- or polycyclic hetaryl hav- ing from 5 to 18 atoms as ring members, where 1, 2, 3 or 4, in particular 1 or 2, of these ring member atoms nitrogen, sulfur or oxygen, while the remainder of are car- bon atoms. R11is preferably selected here from benzyl, phenyl, naphthyl, phenan- threnyl, triphenylenyl, dibenzo[b,d]thiophenyl and thianthrenyl, which radicals may be M / REUCTR-054-PC 19 unsubstituted or may carry a substituent R'" preferably selected from phenyl, halogen and CN. In a particular preferred subgroup (6’) of groups (6) and (6.1) of embodiments the var- iables p and q are independently 0 or 1. In a particular preferred subgroup (6’’) of groups (6), (6.1) and (6’) of embodiments, the variables p and q are both 0, i.e. the central 1,1’-binaphthyl moiety of the com- pound of formulae (I) or (Ia) is devoid of substituents R1and R2. In a particular preferred subgroup (6’’’) of groups (6), (6.1) and (6’) of embodiments, the variables p and q are both 1, i.e. the central 1,1’-binaphthyl moiety of the com- pound of formulae (I) or (Ia) carries one substituent R1and one substituent R2, where R1and R2preferably are independently selected from halogen, CN, phenyl, phenoxy, naphthyl, such as 1-naphthyl or 2-naphthyl, naphthyloxy, such as 1- or 2-naphthyloxy, phenanthrenyl, such as 9-phenanthrenyl, and thianthrenyl, such as 1-thianthrenyl or 2- thianthrenyl. Particular preference is given here to compounds of formulae (I) or (Ia), where the substituents R1and R2have the same meaning and are located in positions 6 and 6’, respectively, of the central 1,1’-binaphthyl moiety. A skilled person will readily appreciate that in the formulae (I) and (Ia) the meanings of A1and A2given in one of groups (1) and (1.1) of embodiments may be combined with the meanings of X1and X2according to one of groups (2) and (2.1) of embodi- ments, with the meanings of Ar1and Ar2according to one or more of groups (3), (3.1), (3’) and (3’’) of embodiments, with the meaning of RAraccording to group (4) of em- bodiments, with the meanings of L1and L2according to one or more of groups (5), (5’) and (5’’) of embodiments, with the meanings of R1and R2according to one or more of groups (6), (6.1), and (6’’’) of embodiments, and also with the meanings of p and q ac- cording to one or more of groups (6’), (6’’) and (6’’’) of embodiments. Apart from that and if not stated otherwise, the variables R11, Rh1, R, R', R", R'", s, p and q either alone or preferably in combination with each other and with the meanings and preferred meanings of the variables A1, A2, Ar1, Ar2, X1, X2, L1, L2, R1, R2, RAr, k and l described above, have the following meanings. R11is preferably selected from the group consisting of C1-C4-alkyl, benzyl, mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms and mono- or polycyclic hetaryl having a total of 5 to 18 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms, where benzyl, aryl and hetaryl are unsubstituted or substituted by 1, 2, 3 or 4 identical or dif- M / REUCTR-054-PC 20 ferent radicals R'", where R'", independently of each occurrence, has one of the mean- ings defined herein, in particular a preferred one. More preferably, R11is selected from methyl, ethyl, benzyl, phenyl, naphthyl, such as 1-naphthyl and 2-naphthyl, phenan- threnyl, such as 9-phenanthrenyl, triphenylenyl, such as 2-triphenylenyl, dibenzo[b,d]thiophenyl, such as 4-dibenzo[b,d]thiophenyl, and thianthrenyl, such as 1- thianthrenyl or 2-thianthrenyl, which are unsubstituted or substituted by 1, 2 or 3 iden- tical or different radicals R'", where R'", independently of each occurrence, has one of the meanings defined herein, in particular a preferred one. Even more preferably, R11is selected from the group consisting of benzyl, phenyl, naphthyl, phenanthrenyl, tri- phenylenyl, dibenzo[b,d]thiophenyl and thianthrenyl, which are unsubstituted. In par- ticular, R11is selected from the group consisting of phenyl, naphthyl, phenanthrenyl and thianthrenyl, which are unsubstituted. Rh1is preferably selected from the group consisting of mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms and mono- or polycyclic hetaryl having a total of 5 to 18 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member at- oms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms. More preferably, Rh1is selected from phenyl, naphthyl, such as 1-naphthyl and 2-naphthyl, phenanthrenyl, such as 9- phenanthrenyl, triphenylenyl, such as 2-triphenylenyl, dibenzo[b,d]thiophenyl, such as 4-dibenzo[b,d]thiophenyl, and thianthrenyl, such as 1-thianthrenyl or 2-thianthrenyl. Even more preferably, Rh1 is selected from the group consisting of benzyl, phenyl, naphthyl, phenanthrenyl, triphenylenyl, dibenzo[b,d]thiophenyl and thianthrenyl, which are unsubstituted. In particular, Rh1is selected from the group consisting of phenyl, naphthyl, phenanthrenyl and thianthrenyl. R is preferably selected from the group consisting of methyl, ethyl, phenyl, benzyl, naphthyl, such as 1-naphthyl or 2-naphthyl, and phenanthrenyl, such as 9-phenan- threnyl, which are unsubstituted or substituted by 1, 2 or 3, especially 1 or 2, identical or different radicals R'", where R'", independently of each occurrence, has one of the meanings defined herein, in particular a preferred one. More preferably, R is selected from the group consisting of phenyl, benzyl, naphthyl and phenanthrenyl, specifically phenyl, benzyl and naphthyl, which are all unsubstituted. R' is preferably selected from the group consisting of phenyl, naphthyl, phenanthrenyl and triphenylenyl, which are unsubstituted or substituted by 1, 2 or 3, especially 1 or 2, identical or different radicals R'", where R'", independently of each occurrence, has one of the meanings defined herein, in particular a preferred one. More preferably, R' is selected from the group consisting of phenyl, naphthyl and phenanthrenyl, which are unsubstituted. M / REUCTR-054-PC 21 R" is preferably selected from the group consisting of hydrogen, methyl, phenyl and naphthyl, where phenyl and naphthyl are unsubstituted or substituted by 1, 2 or 3, es- pecially 1 or 2, identical or different radicals R'", where R'", independently of each oc- currence, has one of the meanings defined herein, in particular a preferred one. More preferably, R" is unsubstituted phenyl or unsubstituted naphthyl. R'" is preferably selected from the group consisting of phenyl, fluorine, chlorine, CN, OCH3and CH3, especially phenyl, fluorine and CN. The variable s is preferably 1 or 2, and in particular is 2. The variables p and q are preferably identical and are also preferably 0 or 1. In a particular subgroup (6a) of group (6’), preferably group (6’’) or (6’’’), and group (1.1) of embodiments, where in formula (Ia) the groups A1and A2are both -CH2-CH2-, the variables p and q are independently O or 1, preferably are both O or are both 1, and where R1and R2are preferably located in positions 6 respectively 6’ of the central 1,1’-binaphthyl moiety of formula (Ia), the compound of formula (Ia) is a compound of the formula (Ib), where the variables p and q are either 0 or 1 and are preferably identical, and where the groups the groups Ar1, Ar2, L1, L2, R1, R2, k and l have the meanings defined herein, in particular the meanings mentioned as preferred. Examples of the particular subgroup (6a) are the compounds of the formula (Ib), in which the combination of the moieties Ar1, Ar2, L1, L2, R1, R2, and the variables p, q, k and l is as defined in any one of the lines 1 to 36 in table A below. Table A M / REUCTR-054-PC 22 Ph: phenyl 4-CN-Ph: 4-cyanophenyl Ar1-1: 1-(2-benzyloxy-1-naphthyl)naphthalene-2-yl Ar2-1: 1-(2-benzyloxy-1-naphthyl)naphthalene-2-yl Ar1-2: 4-CN-naphth-1-yl M / REUCTR-054-PC 23Ar2-2: 4-CN-naphth-1-ylAr1-3: 2-dibenzo[b,d]thiophenyl Ar2-3: 2-dibenzo[b,d]thiophenyl Ar1-4: 4-dibenzo[b,d]thiophenyl Ar2-4: 4-dibenzo[b,d]thiophenyl Ar1-5: 4-dibenzo[b,d]furanyl Ar2-5: 4-dibenzo[b,d]furanyl Ar1-6: 2-dibenzo[b,d]furanyl Ar2-6: 2-dibenzo[b,d]furanyl Ar1-7: 9H-fluoren-2-yl Ar2-7: 9H-fluoren-2-yl Ar1-8: 2-triphenylenyl Ar2-8: 2-triphenylenyl Ar1-9: phenanthren-9-yl Ar2-9: phenanthren-9-yl Ar1-10: thianthren-1-yl Ar2-10: thianthren-1-yl Ar1-11: thianthren-2-yl Ar2-11: thianthren-2-yl Amongst the compounds of formula (I) recited in table A, preference is given to the following compounds of the formula (Ib): - 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1-ethyloxy]-1,1'-binaphthalene - 2-benzyloxy-2’-[(2’-benzyloxy-1,1’-binaphthyl-2-oxy)-1-ethyloxy]-1,1'-binaphtha- lene; - 2,2'-bis(benzyloxy)-1,1’-binaphthalene; - 2,2'-bis(1-naphthylmethyloxy)-1,1’-binaphthalene; - 2,2'-bis(phenoxy)-1,1’-binaphthalene; - 2,2'-bis(1-naphthyloxy)-1,1’-binaphthalene; - 2,2'-bis(4-cyano-phenoxy)-1,1’-binaphthalene; - 2,2'-bis(4-cyano-naphth-1-yloxy)-1,1’-binaphthalene; - 2,2'-bis(4-cyano-phenoxy)-6,6‘-bis(2-naphthyl)-1,1’-binaphthalene; - 2,2'-bis(4-cyano-naphth-1-yloxy)-6,6‘-bis(2-naphthyl)-1,1’-binaphthalene; - 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1-ethyloxy]-6,6‘-diphenyl-1,1'-bi- naphthalene; - 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1-ethyloxy]-6,6‘-bis(2-naphthyl)- 1,1'-binaphthalene; - 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1-ethyloxy]-6,6‘-bis(2-thianthrenyl)- 1,1'-binaphthalene; - 2-benzyloxy-2’-[(2’-benzyloxy-1,1’-binaphthyl-2-oxy)-1-ethyloxy]-6,6‘-diphenyl- 1,1'-binaphthalene; M / REUCTR-054-PC 24 - 2-benzyloxy-2’-[(2’-benzyloxy-1,1’-binaphthyl-2-oxy)-1-ethyloxy]-6,6‘-bis(2-naph- thyl)-1,1'-binaphthalene; - 2,2'-bis(benzyloxy)-6,6‘-diphenyl-1,1’-binaphthalene; - 2,2'-bis(benzyloxy)-6,6‘-bis(2-naphthyl)-1,1’-binaphthalene; - 2,2'-bis(benzyloxy)-6,6‘-bis(1-naphthyl)-1,1’-binaphthalene; - 2,2'-bis[(naphthalen-2-yl)oxy]-1,1'-binaphthalene; - 2,2'-bis[(phenanthren-9-yl)oxy]-1,1'-binaphthalene; - 4,4'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]di(dibenzo[b,d]thiophene); - 2,2'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]di(dibenzo[b,d]thiophene); - 1,1'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]dithianthrene; - 2,2'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]dithianthrene; - 4,4'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]di(dibenzo[b,d]furan); - 2,2'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]di(dibenzo[b,d]furan); - 2,2'-bis[(9H-fluoren-2-yl)oxy]-1,1'-binaphthalene; - 2,2'-bis[(triphenylen-2-yl)oxy]-1,1'-binaphthalene; and - 3,3'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]dithiophene. Amongst the compounds of formula (I) recited in table A, more preference is given to the following compounds of the formula (Ib): - 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1-ethyloxy]-1,1'-binaphthalene - 2-benzyloxy-2’-[(2’-benzyloxy-1,1’-binaphthyl-2-oxy)-1-ethyloxy]-1,1'-binaphtha- lene; - 2,2'-bis(benzyloxy)-1,1’-binaphthalene; - 2,2'-bis(4-cyano-phenoxy)-1,1’-binaphthalene; - 2,2'-bis[(phenanthren-9-yl)oxy]-1,1'-binaphthalene; - 1,1'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]dithianthrene; and - 2,2'-[[1,1'-binaphthalene]-2,2'-diylbis(oxy)]dithianthrene. The compounds of formula (Ib), where k and l are both 1, L1and L2are both single bonds and Ar1and Ar2are identical (het)aryl groups Ar as defined herein, can for ex- ample be prepared by analogy to the 3-step process shown in the following reaction scheme 1. M / REUCTR-054-PC 25 Scheme 1 In step a) of the process 1,1’-bi-2-naphthol (1) is transformed into the 2,2’-bis(2-hy- droxyethoxy) derivative (2) by reacting e.g. with about 2 molar equivalents of a com- pound of the formula (3), where Z is a suitable leaving group, such as a bromide, to- sylate or mesitylate group, in the presence of a base, for instance an oxo base, such as an alkaline metal carbonate, e.g. potassium carbonate. In step b) of the process the two hydroxyl groups of the the compound (2) obtained in step a) are converted into leaving groups Z for example via reaction with mesyl chloride or tosyl chloride in the presence of a suitable base, such as triethylamine, to afford a compound (4). In the fi- nal step c) the compound (4) is reacted with about two molar equivalents of e.g. a (het)aryl alcohol Ar-OH yielding the compound (5) which is a compound (Ib) of the in- vention, where k = l = 1, L1= L2=single bond and Ar1= Ar2= (het)aryl group Ar. The compounds of formula (Ib), where k and l are both 1, L1and L2are both CH2 moi- eties and Ar1and Ar2are identical (het)aryl groups Ar, can for example be prepared by analogy to the process shown in scheme 1, with the exception that in step c) instead of a (het)aryl alcohol Ar-OH for instance a (het)aryl methylbromide Ar-CH2Br is used. M / REUCTR-054-PC 26 The compounds of formula (Ib), where k is 0, l is 1, L1is a single bond, L2is a CH2moiety and Ar1and Ar2are independently seleced from (het)aryl groups as defined herein, can for example be prepared by analogy to the 4-step process shown in the fol- lowing reaction scheme 2. Scheme 2 In step a) of the process 1,1’-bi-2-naphthol (1) is reacted with about 1 molar equiva- lent of e.g. a (het)aryl methylbromide Ar2-CH2Br (6) or a (het)aryl methanol Ar2- CH2OH, in the presence of a base, for instance an oxo base, such as an alkaline metal M / REUCTR-054-PC 27 carbonate, e.g. potassium carbonate. The remaining hydroxyl group of the thus af- forded compound of formula (7) is then in step b) 2-hydroxyethylated to the com- pound (8) e.g. by reaction with compound (3), where Z is a suitable leaving group, such as a bromide, tosylate or mesitylate group, in the presence of a suitable base, such as an alkaline metal carbonate, e.g. potassium carbonate. In step c) the hydroxyl group of the the compound (8) is then converted into a leaving group Z for example via reaction with mesyl chloride or tosyl chloride in the presence of a suitable base, such as triethylamine, to afford a compound (9). In the final step d) the compound (9) is reacted with e.g. a (het)aryl alcohol Ar1-OH (10) yielding the compound (11) which is a compound (Ib) of the invention, where k = 0, l = 1, L1= single bond, L2= CH2, and Ar1and Ar2are independently selected from (het)aryl. The compounds of formula (Ib), where k is 0, l is 1, L1and L2are both CH2 moieties and Ar1and Ar2are independently seleced from (het)aryl groups as defined herein, can for example be prepared by analogy to the process shown in scheme 2, with the ex- ception that in step d) instead of a (het)aryl alcohol Ar1-OH for instance a (het)aryl methanol Ar1-CH2OH is used. Likewise, the compounds of formula (Ib), where k is 0, l is 1, L1and L2are both single bonds and Ar1and Ar2are independently seleced from (het)aryl groups as defined herein, can for example be prepared by analogy to the process shown in scheme 2, with the exception that in step a) instead of a (het)aryl methylbromide Ar2-CH2Br for instance a (het)aryl alcohol Ar2-OH or (het)aryl fluoride Ar2-F is used. The compounds of formula (Ib), where k and l are both 0, L1and L2are both CH2 moi- eties and Ar1and Ar2are identical (het)aryl groups Ar as defined herein, can for exam- ple be prepared by analogy to the process shown in the following reaction scheme 3. Scheme 3 Scheme 3 shows the reaction of 1,1’-bi-2-naphthol (1) with about 2 molar equivalent of e.g. a (het)aryl methylbromide Ar-CH2Br (12), in the presence of a base, for instance an oxo base, such as an alkaline metal carbonate, e.g. potassium carbonate, yielding M / REUCTR-054-PC 28compound (13), which is a compound (Ib) of the invention, where k = l = 0, L1 = L2 =CH2and Ar1= Ar2= (het)aryl group Ar. The compounds of formula (Ib), where k and l are both 0, L1and L2are both single bonds and Ar1and Ar2are identical (het)aryl groups Ar as defined herein, can for ex- ample be prepared by analogy to the process shown in scheme 3, with the exception that instead of a (het)aryl methylbromide Ar-CH2Br (12) for instance a (het)aryl alcohol Ar-OH or a (het)aryl fluoride Ar-F is used. Alternatively, these compounds of formula (Ib), where k and l are both 0, L1and L2are both single bonds and Ar1and Ar2are identical (het)aryl groups Ar as defined herein, can also be prepared by a copper- or copper / iron-catalyzed Ullmann coupling reaction, where 1,1’-bi-2-naphthol (1) is reacted with a (het)aryl halide, typically a (het)aryl bro- mide or iodide, in the presence of a base, such as K2CO3, and a suitable catalyst, such as especially a mixture of copper(I) iodide (CuI) and iron(III) acetylacetonate (Fe(acac)3) in a polar aprotic solvent, such as DMF or DMSO. The conversions shown in schemes 1, 2 and 3 can be accomplished by the reactions described above in the context with these schemes or by apparent variations of these reactions, or, alternatively, by procedures well-established in preparative organic chemistry, or combinations thereof. Further compounds of formula (I) can be prepared by employing apparent variations of the reactions described above and combinations thereof with procedures well-estab- lished in preparative organic chemistry. The reaction mixtures obtained in the individual steps of the syntheses for preparing the compounds described in reaction schemes 1, 2 and 3 above are usually worked up in a conventional way, e.g. by mixing with water, separating the phases and, where appropriate, purifying the crude products by washing, chromatography or crystalliza- tion. The intermediates in some cases result in the form of colorless or pale brownish, viscous oils, which are freed of volatiles or purified under reduced pressure and at moderately elevated temperature. If the intermediates are obtained as solids, the puri- fication can be achieved by recrystallization or washing procedures, such as slurry washing. The starting compounds used in the syntheses shown in schemes 1, 2 and 3 above to prepare compounds of formula (I) are commercially available or can be prepared by methods known from the art. M / REUCTR-054-PC 29 The compounds of the present invention can be obtained in high purity, which means that a product is obtained, which does not contain significant amounts of organic impu- rities different from the compound of formula (I), except for volatiles. Usually, the pu- rity of compounds of formula (I) is at least 95%, in particular at least 98% and espe- cially at least 99%, based on the non-volatile organic matter, i.e. the product contains at most 5%, in particular at most 2% and especially at most 1% of non-volatile impuri- ties different from the compound of formula (I). The term "volatiles" refers to organic compounds, which have a boiling point of less than 200°C at standard pressure (105Pa). Consequently, non-volatile organic matter is understood to mean compounds having a boiling point, which exceeds 200°C at stand- ard pressure. It is a particular benefit of the invention that the compounds of formula (I) and like- wise their solvates, can often be obtained in crystalline form. In the crystalline form the compound of formula (I) may be present in pure form or in the form of a solvate with water or an organic solvent. Therefore, a particular aspect of the invention relates to the compounds of formula (I), which are essentially present in crystalline form. In particular, the invention relates to crystalline forms, where the compound of formula (I) is present without solvent and to the crystalline solvates of the compounds of for- mula (I), where the crystals contain a solvent incorporated. It is a particular benefit of the invention that the compounds of the formula (I) and likewise their solvates, can often be easily crystallized from conventional organic sol- vents. This allows for an efficient purification of the compounds of formula (I). Suitable organic solvents for crystallizing the compounds of the formula (I) or their solvates, in- clude but are not limited to aromatic hydrocarbons such as toluene or xylene, aliphatic ketones in particular ketones having from 3 to 6 carbon atoms, such as acetone, me- thyl ethyl ketone, methyl isopropyl ketone or diethyl ketone, aliphatic and alicyclic ethers, such as diethyl ether, dipropyl ether, methyl isobutyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, dioxane or tetrahydrofuran, 2-methyl-tetrahydrofuran, ali- phatic-aromatic ethers, such as anisole, and aliphatic alcohols having 1 to 4 carbon at- oms, such as methanol, ethanol or isopropanol, as well as mixtures thereof. It may be beneficial to subject a dissolved crude preparation of a compound of formula (I) to fil- tration, e.g. over cellite, prior to the crystallization step, in order to remove solid com- ponents that may be present in a crude preparation. Furthermore, impurities, especially color forming impurities, that may be present in a crude preparation of a compound of formula (I) can be removed at any stage of the purification process, e.g. before a filtration step or a crystallization step, by standard procedures, such as treatment with an adsorbent, e.g. activated charcoal. M / REUCTR-054-PC 30 Alternatively, the compounds of the formula (I) and likewise their solvates, can be ob- tained in purified form by employing other simple and efficient methods for purifying the raw products of these compounds, such as in particular slurry washing the raw sol- ids obtained directly after the conversion to prepare the compounds of formula (I). Slurry washing is typically conducted at ambient temperature or elevated temperatures of usually about 30 to 90°C, in particular 40 to 80°C. Suitable organic solvents here are in principle the same as those listed above as being suitable for crystallizing the com- pounds of formula (I), such as in particular the mentioned aromatic hydrocarbons, ali- phatic ketones and aliphatic ethers, e.g. toluene, methyl ethyl ketone and methyl tert- butyl ether. Accordingly, the compounds of formula (I) used as additives for thermoplastic resins, in particular polycarbonates, as defined herein, can be easily prepared and obtained in high yield and high purity. In particular, compounds of formula (I) can be obtained in crystalline form, which allows for an efficient purification to the degree required in the preparation of optical resins. In particular, these compounds can be obtained in a pu- rity which provides for high refractive indices and also low haze, which is particularly important for the use in the preparation of optical resin compositions of which the opti- cal devise is made of. In conclusion, the compounds of formula (I) are particularly use- ful as additives in the preparation of the optical resin compositions. The present invention further relates to resin composition comprising at least one resin and at least one additive selected from the compounds of formulae (I), (Ia) and (Ib) defined above. The compounds (I), (Ia) and (Ib) are particularly useful as additives for thermoplastic resins, especially because they significantly reduce the glass-transistion temperature (Tg) of the resins and thus improve their fluidity and moldibility virtually without affecting their optical properties. Therefore, the compounds (I), (Ia) and (Ib) are specifically suited as additives in thermoplastic resins to be used for preparing lenses and other optical devices. Such thermoplastic resins are typically selected from polycarbonates, polyestercarbonates,polyesters and mixtures thereof, especially se- lected from aromatic polycarbonates, aromatic polyestercarbonates, aromatic polyes- ters and mixtures thereof. Accordingly, a particular group of embodiment relates to a resin composition compris- ing at least one thermoplastic resin which is a polycarbonate, polyestercarbonate, poly- ester or a mixture thereof, and especially is an aromatic polycarbonate, an aromatic polyestercarbonate, an aromatic polyester or a mixture thereof. Suitable thermoplastic resins which can be used in combination with the compounds of the formula (I) and which are particularly suitable for producing optical devices are well known in the art, e. g. from JP 2002-332345 A, US 9,360,593, US 2016 / 0319069, JP 2002-332345 A, JP 2018002893, JP 2018002894, JP 2018002895, M / REUCTR-054-PC 31 WO 2016 / 147847, WO 2019 / 154727, WO 2020 / 079225, WO 2020 / 0175663, WO 2023 / 036868 and WO 2023 / 208837. In this context, preference is given to resin compositions comprising at least one ther- moplastic resin selected from polycarbonates, polyestercarbonates, polyesters or mix- tures thereof, and especially selected from aromatic polycarbonates, aromatic polyes- tercarbonates, aromatic polyesters and mixtures thereof. Even more preference is given in this regard to resins comprising at least one aromatic polycarbonate, aromatic polyestercarbonate, aromatic polyester or mixture thereof, where the resins are made up of structural units which comprise at least one of a structural units represented by formulae (II-1) and (II-2) below: where # represents a connection point to a neighboring structural unit; R0are independently selected from C1-C6-alkylene which are unsubstituted or sub- stituted by 1, 2, 3 or 4 identical or different radicals R'", where R'" is selected from the group consisting of phenyl, CN, halogen, OCH3, CH3, N(CH3)2 and C(O)CH3; a1, b1, a2 and b2 are independently selected from 0 to 10; A1a, A2aA1band A2bare independently selected from the group consisting of O, C=O, C(O)O, S and SO2; M / REUCTR-054-PC 32R1 and R2 are independently selected from the group consisting of halogen, C1-C20-al-kyl, C1-C20-alkoxy, C1-C20-alkyl, C5-C20-cycloalkyl, C6-C20-aryl, C5-C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulphur and oxygen, -C≡C-Rh1, where Rh1 is selected from C6-C20-aryl and C5-C20-hetaryl having 1 or more atoms se- lected from nitrogen, sulfur and oxygen; C2-C3-alkynyl, CN, R11a, OR11a, CHsR'3-s, NR11a2, C(O)R and CH=CHR'', it being possible that R1and R2are identi- cal or different if m1+n1>1 or m2+n2>1, where s on each occurrence is 0, 1 or 2; R11ais selected from the group consisting of C1-C20-alkyl, benzyl, C6-C20-aryl, C5-C20- hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulfur and oxygen, where benzyl, C6-C20-aryl and C5-C20-hetaryl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; m1and n1are independently selected from 0 to 6; m2and n2are independently selected from 0 to 4; Z1and Z2are independently selected from a single bond and fluorene ring which is un- substituted or substituted by 1, 2, 3, 4 or 5 identical or different radicals R'"', where R'"' is selected from the group consisting of halogen, methyl, methoxy, CN, OCH3, CH3, N(CH3)2, C(O)CH3, phenyl, naphthyl and phenanthrenyl, and where the radicals R, R', R" and R'" have the meanings defined herein above in the context of the formulae (I) and (Ia), and especially have the meanings mentioned herein as preferred. R11ahas in particular one of the preferred meanings given for R11in the context of formulae (I) and (Ia). In formulae (II-1) and (II-2) the variables A1a, A2a, A1b, A2b, R0, R1, R2, Z1, Z2, a1, a2, b1, b2, n1, n2, m1and m2on their own or preferably in any combination preferably have the following meanings: Both variables R0in formula (II-1) and (II-2), respecitvely, are identical or different and independently selected from C1-C6-alkylene, preferably C1-C4-alkylene, which are unsubstituted or substituted by 1, 2, 3 or 4, preferably by 1 or 2, identical or different radicals R'", where R'" in each occurance has one of the meanings defined herein, in particular one of those mentioned herein as preferred. In a particular group (7) of embodiments, both variables R0in formula (II-1) and (II- 2), respectively, are independently selected from unsubstituted C2-C6-alkandiyl which is preferably linear, such as 1,2-ethandiyl (CH2-CH2), 1,3-propandiyl or 1,4-butandiyl, and in particular 1,2-ethandiyl. In this context it is particularly preferred that both variables R0in formula (II-1) or (II-2) are identical to each other. M / REUCTR-054-PC 33 In a preferred subgroup (7.1) of group (7) of embodiments the both variables R0in formula (II-1) or (II-2) are both -CH2-CH2-. In a particular group (8) of embodiments, both variables a1and b1of formula (II-1) or both variables a2and b2of formula (II-2) are idependently selected from 0 to 4 and in particular from 0 to 2. In a preferred subgroup (8.1) of group (8) of embodiments, both variables a1and b1of formula (II-1) or both variables a2and b2of formula (II-2) are 1. In a particular group (9) of embodiments, the moieties A1aand A2ain formula (II-1) or the moieties A1band A2bin formula (II-2) are independently or identically O, C=O or C(O)O, and are preferably identical to each other. In a preferred subgroup (9.1) of group (9) of embodiments the moieties A1aand A2ain formula (II-1) or the moieties A1band A2bin formula (II-2) are both O. In a particular group (10) of embodiments, the moiety Z1in formula (II-1) or the moi- ety Z2in formula (II-2) is selected from a single bond and a fluorene ring which is un- substituted or substituted by 1, 2 or 3, in particular 1 or 2, identical or different radi- cals R'"', where R'"' in each case is selected from the group consisting of chlorine, fluo- rine, methyl, methoxy, CN, phenyl and naphthyl, such as 1-naphthyl or 2-naphthyl. In a preferred subgroup (10’) of group (10) of embodiments, the moiety Z1in formula (II-1) or the moiety Z2in formula (II-2) is selected from a single bond and a fluorene ring which is substituted by 2 identical radicals R'"', which are located in equivalent po- sitions of the fluorene ring, such as e.g. in positions 2 and 7 or in positions 3 and 8, where the radicals R'"' have the meaning defined above, in particular one of the pre- ferred meanings mentioned herein. In a preferred subgroup (10’’) of groups (10) and (10’) of embodiments, the moiety Z1in formula (II-1) or the moiety Z2in formula (II-2) is selected from a single bond and an fluorene ring which is unsubstituted. In a particular group (11) of embodiments, both radicals R1and R2of formula (II-1) re- spectively (II-2), if present, are independently selected from the group consisting of halogen, C2-C3-alkynyl, CN, R11aand OR11a, where R11ais in particular selected from the group consisting of benzyl, mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms or are mono- or polycyclic hetaryl having a total of 5 to 18 atoms, which are ring members, where 1, 2, 3 or 4, in particular 1 or 2, of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these M / REUCTR-054-PC 34 ring member atoms of hetaryl are carbon atoms, where aryl and hetaryl are unsubsti- tuted or carry a substituent R'". In a preferred subgroup (11.1) of group (11) of embodiments, both radicals R1and R2of formula (II-1) or (II-2), if present, are independently selected from the group con- sisting of halogen, C2-C3-alkynyl, CN, R11aand OR11a, where R11ais selected from benzyl and mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms and mono- or polycyclic hetaryl having from 5 to 18 atoms as ring members, where 1, 2, 3 or 4, in particular 1 or 2, of these ring member atoms nitrogen, sulfur or oxygen, while the remainder of are carbon atoms. R11ais preferably selected here from benzyl, phe- nyl, naphthyl, phenanthrenyl, triphenylenyl, dibenzo[b,d]thiophenyl and thianthrenyl, more preferably from benzyl, phenyl, naphthyl, phenanthrenyl and thianthrenyl, which radicals may be unsubstituted or may carry a substituent R'" preferably selected from phenyl, halogen, especially fluorine or chlorine, and CN. In a particular preferred subgroup (11’) of groups (11) and (11.1) of embodiments the variables m1and n1or m2and n2are independently 0 or 1. In a particular preferred subgroup (11’’) of groups (11), (11.1) and (11’) of embodi- ments, both variables m1and n1of formula (II-1) or both variables m2and n2of for- mula (II-2) are 0, i.e. the aromatic core of the structural unit of formula (II-1) and (II- 2), respectively, is devoid of substituents R1and R2. In a particular preferred subgroup (11’’’) of groups (11), (11.1), (11’) and (11’’) of em- bodiments, both variables m1and n1of formula (II-1) or both variables m2and n2of formula (II-2) are 1, i.e. the aromatic core of the structural unit of formula (II-1) and (II-2), respectively, carries 1 substituent R1and 1 substituent R2, where R1and R2pref- erably are independently selected from fluorine, chlorine, CN, phenyl, phenoxy, naph- thyl, such as 1-naphthyl or 2-naphthyl, naphthyloxy, such as 1- or 2-naphthyloxy, phe- nanthrenyl, such as 9-phenanthrenyl, and thianthrenyl, such as 1-thianthrenyl or 2-thi- anthrenyl. Particular preference is given here to structural units of formulae (II-1) or (II-2), where the substituents R1and R2have the same meaning and are located in equivalent positions of the two phenyl or naphthyl moieties of the aromatic core of for- mula (II-1) and (II-2), respectively. A skilled person will readily appreciate that in the formulae (II-1) and (II-2), respec- tively, the meanings of the radicals R0given in one of groups (7) and (7.1) of embodi- ments may be combined with the meanings of the variables a1and b1or of the varia- bles a2and b2according to one of groups (8) and (8.1) of embodiments, with the meanings of the moieties A1aand A2aor of the moieties A1band A2baccording to one of groups (9) and (9.1) of embodiments, with the meanings of Z1and Z2according to one or more of groups (10), (10’) and (10’’) of embodiments, with the meanings of R1and M / REUCTR-054-PC 35R2 according to one or more of groups (11), (11.1), (11’’) and (11’’’) of embodiments,and also with the meanings of m1and n1or m2and n2according to group (11’) of em- bodiments or group (11’’) of embodiments. Apart from that and if not stated otherwise, in formulae (II-1) and (II-2) the variables R11a, Rh1, R, R', R", R'" and s either alone or preferably in combination with each other and with the meanings and preferred meanings of the variables A1a, A2a, A1b, A2b, R0, R1, R2, Z1, Z2, a1, a2, b1, b2, n1, n2, m1and m2described above, have the meanings de- fined above, and in particular the meanings mentioned herein as preferred. As apparent to a skilled person thermoplastic resins, such as especially those selected from polycarbonates, polyestercarbonates, polyesters or mixtures thereof, which com- prise at least one of the above structural units of formulae (II-1) and / or (II-2), can be prepared from corresponding monomers. It is thus also apparent to the skilled person that these monomers are of formulae (VI-1) and (VI-2), which are derived from formu- lae (II-1) or (II-2) by replacing the moieties #-A1aand #-A2aor #-A1band #-A2bwith groups capable of being converted in particular into ester or carbonate linkages, such as especially OH or C(O)ORx, where Rxis in preferably selected from hydrogen, phenyl, benzyl and C1-C4-alkyl. The monomers of formula (VI-1) or (VI-2) can be prepared in analogy to procedures well known in the art, as described e.g. in WO2020 / 079225 and WO2023 / 036868, to which full reference is made. In the context of the present invention preference is also given to resin compositions comprising at least one aromatic polycarbonate, aromatic polyestercarbonate, aromatic polyester or mixture thereof, where the resins included in these compositions are made up of structural units which comprise at least one of a structural units represented by formula (II-3) below: where M / REUCTR-054-PC 36 # represents a connection point to a neighboring structural unit; C1and C2are independently selected from the group consisting of a mono- or polycy- clic arylene having from 6 to 26 carbon atoms as ring members and a mono- or polycyclic hetarylene having a total of 5 to 26 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetarylene are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetarylene are carbon atoms, where mono- or polycyclic arylene and mono- or polycyclic hetarylene are unsubstituted or carry 1, 2, 3 or 4 radicals RAr; RAris selected from the group consisting of CN, R, OR, CHtR'3-t, NR2and CH=CHR'', where RArmay be identical or different if more than one is present on the same (het)arylene group, where t on each occurrence is 0, 1 or 2; R is as defined in the context of formulae (1) and (1a) and inpartiuclar selected from the group consisting of C1-C4-alkyl, phenyl, naphthyl, phenanthrenyl and tri- phenylenyl, where phenyl, naphthyl, phenanthrenyl and triphenylenyl are unsub- stituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R' is as defined in the context of formulae (1) and (1a) and inpartiuclar selected from the group consisting of phenyl, naphthyl, phenanthrenyl and triphenylenyl, where phenyl, naphthyl, phenanthrenyl and triphenylenyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R'' is as defined in the context of formulae (1) and (1a) and inpartiuclar selected from hydrogen, methyl, phenyl and naphthyl, where phenyl and naphthyl are un- substituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R'" is as defined in the context of formulae (1) and (1a) and inpartiuclar selected from the group consisting of phenyl, halogen, OCH3, CH3, N(CH3)2 and C(O)CH3; R1and R2are independently selected from the group consisting of halogen, C1-C20-al- kyl, C1-C20-alkoxy, C1-C20-alkyl, C5-C20-cycloalkyl, C6-C20-aryl, C5-C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulphur and oxygen, -C≡C-Rh1, where Rh1 is selected from C6-C20-aryl and C5-C20-hetaryl having 1 or more atoms se- lected from nitrogen, sulfur and oxygen; C2-C3-alkynyl, CN, R11a, OR11a, CHsR'3-s, NR11a2, C(O)R and CH=CHR'', it being possible that R1and R2are identi- cal or different if p+q>1, where s on each occurrence is 0, 1 or 2; R11ais selected from the group consisting of C1-C20-alkyl, benzyl, C6-C20-aryl, C5-C20- hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulfur and oxygen, where benzyl, C6-C20-aryl and C5-C20-hetaryl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; p and q are independently 0, 1 or 2; and M / REUCTR-054-PC 37A1c and A1care independently selected from the group consisting of O, -CH2O, C=O,C(O)O, S and SO2; and where the radicals R, R', R" and R'" have the meanings defined herein above, and es- pecially have the meanings mentioned herein as preferred. R11ahas in particular one of the preferred meanings given for R11in the context of formulae (I) and (Ia). In formula (II-3) the variables A1c, A2c, R1, R2, C1, C2, RAr, p and q on their own or pref- erably in any combination preferably have the following meanings: In a particular group (12) of embodiments, the moieties A1cand A2cin formula (II-3) are independently selected from O, -CH2O, C=O and C(O)O, and are preferably identi- cal to each other. In a preferred subgroup (12.1) of group (12) of embodiments the moieties A1cand A2cin formula (II-3) are both -CH2O. In a preferred group (13) of embodiments the variables C1and C2in formula (II-3) are independently selected from the group consisting of mono- or polycyclic arylene having from 6 to 22, in particular 6 to 18, carbon atoms as ring members and mono- or poly- cyclic hetarylene having from 9 to 24, in particular 9 to 20, atoms as ring members, where 1, 2, 3 or 4 of these atoms are nitrogen, oxygen or sulfur atoms, and in particu- lar 1, 2 or 3, such as 1 or 2, of these atoms are oxygen or sulfur atoms, while the re- mainder of these atoms are carbon atoms, where mono- or polycyclic arylene and mono- or polycyclic hetarylene are unsubstituted or carry 1, 2, 3 or 4, in particular 1 or 2, radicals RAr, where RArhas one of the meanings defined herein, especially one of the meanings mentioned as preferred. In an specific subgroup (13.1) group (13) of embodiments, C1and C2are inde- pendently selected from the group consisting of phenylene, naphthylene, bi- phenylylene, benzo[b]furanylene, dibenzo[b,d]furanylene, benzo[b]thienylene, dibenzo[b,d]thienylene, 9H-fluorenylene, oxanthrenylene, thianthrenylene, phenoxathi- inylene, 9H-xanthylene and 9H-thioxanthylene, preferably from the group consisting of phenylene, naphthylene, biphenylylene, dibenzo[b,d]thienylene, 9H-fluorenylene, oxanthrenylene, thianthrenylene, phenoxathiinylene, 9H-xanthylene and 9H-thioxanth- ylene, and in particular from the group consisting of phenylene, naphthylene, bi- phenylylene, dibenzo[b,d]thienylene and thianthrenylene, where the aforementioned mono- or polycyclic arylene and mono- and polycyclic hetarylene are unsubstituted or carry 1 or 2 radicals RAr. In an particularly preferred subgroup (13.2) of groups (13) and (13.1) of embodi- ments, C1and C2have the same meaning. M / REUCTR-054-PC 38In a particular group (14) of embodiments the one or more radicals RAr in formula(II-3) are selected from the group consisting of R, OR and NR2, especially R and OR, where RArmay be identical or different if more than one RAris present on the same (het)aryl group. In this context R has one of the meanings defined herein and is in par- ticular selected from the group consisting of methyl, ethyl, phenyl, benzyl, naphthyl, such as 1-naphthyl or 2-naphthyl, and phenanthrenyl, such as 9-phenanthrenyl, in par- ticular from phenyl, benzyl and naphthyl, where R may be substituted with 1 or 2 radi- cals R'" and preferably is unsubstituted. Accordingly, in this group (14) of embodi- ments, the one or more radicals RArare preferably selected from the group consisting of C1-C4-alkyl, phenyl, benzyl, naphthyl, phenanthrenyl, C1-C4-alkoxy, phenoxy, ben- zyloxy, naphthyloxy, phenanthrenyloxy, di(C1-C4-alkyl)amino, diphenylamino, dibenzyl- amino, dinaphthylamino, and diphenanthrenylamino, and especially from the group consisting of phenyl, benzyl, naphthyl, phenoxy, benzyloxy and naphthyloxy. In a particular group (15) of embodiments, the variables p and q are independently se- lected from 0 and 1, and are especially both either 0 or 1. In a particular group (16) of embodiments, both radicals R1and R2of formula (II-3), if present, are independently selected from the group consisting of halogen, C2-C3-al- kynyl, CN, R11aand OR11a, where R11ais in particular selected from the group consisting of benzyl, mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms or are mono- or polycyclic hetaryl having a total of 5 to 18 atoms, which are ring mem- bers, where 1, 2, 3 or 4, in particular 1 or 2, of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms, where aryl and hetaryl are unsubstituted or carry a substituent R'". In a preferred subgroup (16.1) of group (16) of embodiments, both radicals R1and R2of formula (II-3), if present, are independently selected from the group consisting of halogen, C2-C3-alkynyl, CN, R11aand OR11a, where R11ais selected from benzyl and mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms and mono- or polycyclic hetaryl having from 5 to 18 atoms as ring members, where 1, 2, 3 or 4, in particular 1 or 2, of these ring member atoms nitrogen, sulfur or oxygen, while the re- mainder of are carbon atoms. R11ais preferably selected here from benzyl, phenyl, naphthyl, phenanthrenyl, triphenylenyl, dibenzo[b,d]thiophenyl and thianthrenyl, more preferably from benzyl, phenyl, naphthyl and thianthrenyl, which radicals may be un- substituted or may carry a substituent R'" preferably selected from phenyl, halogen, especially chlorine or fluorine, and CN. In a preferred subgroup (16.2) of groups (16) and (16.1) of embodiments, the radicals R1and R2of formula (II-3), if present, are independently selected from fluorine, chlo- rine, CN, phenyl, phenoxy, naphthyl, such as 1-naphthyl or 2-naphthyl, naphthyloxy, M / REUCTR-054-PC 39 such as 1- or 2-naphthyloxy, phenanthrenyl, such as 9-phenanthrenyl, and thi- anthrenyl, such as 1-thianthrenyl or 2-thianthrenyl. Particular preference is given here to structural units of formula (II-3), where the radicals R1and R2have the same mean- ing. In a particular preferred subgroup (16.3) of groups (16), (16.1) and (16.2) of embodi- ments, the formula (II-3) is represented by the formula (II-3b), where each of the variables A1c, A2c, R1, R2, C1and C2has the meanings defined herein, in particular one of those mentioned herein as preferred. A skilled person will readily appreciate that in the formula (II-3) the meanings of the moieties A1cand A2cgiven in one of groups (12) and (12.1) of embodiments may be combined with the meanings of the groups C1and C2according to one or more of groups (13), (13.1) and (13.2) of embodiments, with the meanings of the radical RAraccording to the group (14) of embodiments, with the meanings of the variables p and q according to group (15) of embodiments, and also with the meanings of R1and R2according to one or more of groups (16), (16.1), (16.2) and (16.3) of embodiments. Apart from that and if not stated otherwise, in formula (II-3) the variables R11a, Rh1, R, R', R", R'" and s either alone or preferably in combination with each other and with the meanings and preferred meanings of the variables A1c, A2c, R1, R2, C1, C2, RAr, p and q described above, have the meaning defined above, and in particular the meanings mentioned herein as preferred. As apparent to a skilled person thermoplastic resins, such as especially those selected from polycarbonates, polyestercarbonates, polyesters or mixtures thereof, which com- prise at least one of the above structural units of formula (II-3), can be prepared from corresponding monomers. It is thus also apparent to the skilled person that these monomers are of formula (VI-3), which is derived from formula (II-3) by replacing the moieties #-A1cand #-A2cwith groups capable of being converted especially into ester or carbonate linkages, such as especially CH2OH or C(O)ORx, where Rxis in preferably selected from hydrogen, phenyl, benzyl and C1-C4-alkyl. M / REUCTR-054-PC 40 The monomers of formula (VI-3) can be prepared in analogy to procedures well known in the art, as described e.g. in WO2024 / 068860, to which full reference is made. A skilled person will also appreciate that the structural units of the formulae (II-1), (II- 2) and (II-3) are repeating units within the polymer chains of thermoplastic resins that are preferably contained in the resin compositions of the present invention. In addition to the structural units of the formulae (II-1), (II-2) and (II-3), respectively, the thermoplastic resin may have structural units different therefrom. In a preferred embodiment, these further structural units are derived from aromatic monomers of the formula (IV) resulting in structural units of the formula (V): HO-Rz-A3-Rz-OH (IV) #-O-Rz-A3-Rz-O-# (V) where # represents a connection point to a neighboring structural unit; A3is a polycyclic radical bearing at least 2 benzene rings, wherein the benzene rings may be connected by W and / or directly fused to each other and / or fused by a non-benzene carbocycle and / or fused by two non-benzene carbocycles that are linked via a linker L, where A3is unsubstituted or substituted by 1, 2 or 3 radicals Raa, which are selected from the group consisting of halogen, C1-C6-alkyl, C5-C6- cycloalkyl, phenyl, naphthyl, 1,2-dihydroacenaphthylenyl, phenanthrenyl, pyrenyl, triphenylenyl, benzo[b]furanyl, dibenzo[b,d]furanyl, benzo[b]thienyl, dibenzo[b,d]thienyl and thianthrenyl; W is selected from the group consisting of a single bond, O, C=O, S, S(O), SO2, CH2, CH-Ar, C(Ar)2, CH(CH3), C(CH3)2 and a radical of the formula (A') where Q’ represents a single bond, O, C=O or CH2; R7a, R7b, independently of each other are selected from the group consisting of hydrogen, fluorine, CN, R, OR, CHvR’3-v, NR2, C(O)R and C(O)NH2, where R and R’ are as defined herein and v is 0, 1 or 2; and * represents the connection point to a benzene ring; M / REUCTR-054-PC 41L is selected from a single bond, C1-C4-alkylene, C4-C7-cycloalkylene, C4-C7-cycloal-kylenedimethylene, phenylenedimethylene, where L is unsubstituted or substi- tuted by 1 or 2 radicals RL, which are selected from the group consisting of C1-C4- alkyl, halogen, C1-C4-haloalkyl, C4-C7-cycloalkyl and phenyl, Ar is selected from the group consisting of mono- or polycyclic aryl having from 6 to 26 carbon atoms as ring atoms and mono- or polycyclic hetaryl having a total of 5 to 26 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryl are selected from nitrogen, sulphur and oxygen, while the re- mainder of these ring member atoms of hetaryl are carbon atoms, where Ar is unsubstituted or substituted by 1, 2 or 3 radicals Rab, which are selected from the group consisting of halogen, phenyl and C1-C4-alkyl; Rzis a single bond, Alk3, O-Alk4-, O-Alk4-[O-Alk4-]w- or O-Alk5-C(O)- where O is bound to A3, and where w is an integer from 1 to 10; Alk3is C1-C4-alkandiyl; Alk4is C2-C4-alkandiyl; and Alk5is C1-C4-alkandiyl. If Rzin formula (IV) is O-Alk5-C(O), the esters, in particular the C1-C4-alkyl esters, of the monomers of formula (IV) may be used instead. In the context of formulae (IV) and (V), A3is in particular either a polycyclic radical bearing 2 benzene or naphthaline rings, wherein the benzene rings are connected by W or fused by two non-benzene carbocycles that are linked via a linker L, where W is in particular selected from the group consisting of a single bond, S, S(O), SO2, C(CH3)2, and a radical A' and where L is a single bond or C1-C4-alkylene. In the context of formulae (IV) and (V), Rzis in particular O-Alk4-, where Alk4is in par- ticular linear alkandiyl having 2 to 4 carbon atoms and especially O-CH2CH2. Amongst the monomers of formula (IV) preference is given to monomers of the gen- eral formulae (IV-1) to (IV-8) M / REUCTR-054-PC 42 where a and b are 0, 1, 2 or 3, in particular 0 or 1; a’ and b’ are 0, 1, 2 or 3, in particular 0 or 1; c and d are 0, 1, 2, 3, 4 or 5, in particular 0 or 1; e and f are 0, 1, 2, 3, 4 or 5, in particular 0 or 1; W’ is S, S(O), SO2, O, single bond, CH2, CH(CH3), C(CH3)2, in particular S, S(O), SO2or C(CH3)2; and where Rz, Raa, Rab, R7a, R7band L are as defined for formula (IV) and where Rzis in particular selected from a single bond, CH2and OCH2CH2, M / REUCTR-054-PC 43 Amongst the monomers of formula (IV) particular preference is given to monomers of the general formulae (IV-11) to (IV-22), where Rzand Raaare as defined herein and Rzis in particular selected from a single bond, CH2and O-CH2CH2, and especially is O- CH2CH2: (IV-17) (IV-18) M / REUCTR-054-PC 44 (IV-21) (IV-22) Examples of compounds of the formulae (IV-11) to (IV-22) are 9,9-bis(4-hydroxy- phenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxy-3-iso- propylphenyl)fluorene, 9,9-bis(4-hydroxy-3-tert.-butylphenyl)fluorene, 9,9-bis(4-hy- droxy-3-cyclohexylphenyl)fluorene, 9,9-bis(4-hydroxy-3-phenylphenyl)fluorene, 9,9- bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF), 9,9-bis(4-(2-hydroxyethoxy)-3- methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene, 9,9- bis(4-(2-hydroxyethoxy)-3-tert.-butylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3- cyclohexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene (BPPEF), 9,9-bis(6-hydroxy-2-naphthyl)fluorene, 9,9-bis(6-(2-hydroxyethoxy)-2-naph- thyl)fluorene also termed 9,9-bis(6-(2-hydroxyethoxy)naphthalene-2-yl)fluorene (BNEF) or 6,6′-(9-fluorenylidene)bis(2-naphthyloxyethanol) (NOLE), 10,10-bis(4-hy- droxyphenyl)anthracen-9-on, 10,10-bis(4-(2-hydroxyethoxy)phenyl)anthracen-9-on, 4,4'-dihydroxytetraphenylmethane, 4,4'-di-(2-hydroxyethoxy)-tetraphenylmethane, 3,3'-diphenyl-4,4'-dihydroxy-tetraphenylmethane, di-(6-hydroxy-2-naphthyl)-diphenyl- methane, 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-diphenyl-phenyl]-1-methyl-ethyl]-2,6-di- phenyl-phenoxy]ethanol, 2-[4-[1-[4-(2-hydroxyethoxy)-3-phenyl-phenyl]-1-methyl- ethyl]-2,6-diphenyl-phenoxy]ethanol, 9,9’-dihydroxymethyl-9,9’-difluorene, 2,2'-[1,1'- binaphthalene-2,2'-diylbis(oxy)]diethanol also termed 2,2'-bis(2-hydroxyethoxy)-1,1'- binaphthyl or 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene (BNE), 2,2'-bis(1-hy- droxymethoxy)-1,1'-binaphthyl, 2,2'-bis(3-hydroxypropyloxy)-1,1'-binaphthyl, 2,2'- bis(4-hydroxybutoxy)-1,1'-binaphthyl, 2,2'-((6,6'-diphenyl-[1,1'-binaphthalene]-2,2'- diyl)bis(oxy))bis(ethan-1-ol) (DPBN), 2,2'-bis(2-hydroxyethoxy)-6,6'-diphenyl-1,1'- binaphthalene (DPBN), 2,2'-bis(2-hydroxyethoxy)-6,6'-di(naphthalene-1-yl)-1,1'- M / REUCTR-054-PC 45 binaphthalene, 2,2'-bis(2-hydroxymethoxy)-6,6'-diphenyl-1,1'-binaphthalene, 2,2'- bis(2-hydroxymethoxy)-6,6'-di(naphthalene-1-yl)-1,1'-binaphthalene, 2,2'-bis(2-hydrox- ypropoxy)-6,6'-diphenyl-1,1'-binaphthalene, 2,2'-bis(2- hydroxypropoxy)-6,6'- di(naph- thalene-1-yl)-1,1'-binaphthalene, 2,2'-bis(2-hydroxyethoxy)-6,6'-di(naphthalene-2-yl)- 1,1'-binaphthalene, 2,2'-bis(2-hydroxyethoxy)-6,6'-di(9-phenanthrenyl)-1,1'-binaphtha- lene, 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-di(naphthalen-1-yl)-phenyl]-1-methyl-ethyl]- 2,6-di(naphthalen-1-yl)-phenoxy]ethanol, 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-di(naph- thalen-2-yl)-phenyl]-1-methyl-ethyl]-2,6-di(naphthalen-2-yl)-phenoxy]ethanol, 2-[4-[1- [4-(2-hydroxyethoxy)-3,5-di(phenanthren-9-yl)-phenyl]-1-methylethyl]-2,6-di(phenan- thren-9-yl)-phenoxy]ethanol, 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-di(1,2- dibenzo[b,d]thien-4-yl)-phenyl]-1-methyl-ethyl]-2,6-di(1,2-dibenzo[b,d]thien-4-yl)-phe- noxy]ethanol, 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-di(thiantren-1-yl)-phenyl]-1-methyl- ethyl]-2,6-di(thianthren-1-yl)-phenoxy]ethanol, 2-[4-[4-(2-hydroxyethoxy)-3,5-di(naph- thalene-1-yl)phenyl]sulfonyl-2,6-di(naphthalene-1-yl)-phenoxy]ethanol, 2-[4-[4-(2-hy- droxyethoxy)-3,5-di(naphthalene-2-yl)phenyl]sulfonyl-2,6-di(naphthalene-2-yl)-phe- noxy]ethanol, 2-[4-[4-(2-hydroxyethoxy)-3,5-di(phenanthren-9-yl)phenyl]sulfonyl-2,6- di(phenanthren-9-yl)-phenoxy]ethanol, 2-[4-[4-(2-hydroxyethoxy)-3,5-di(thianthrene- 1-yl)phenyl]sulfonyl-2,6-di(thianthrene-1-yl)phenoxy]ethanol and 2-[4-[4-(2-hydroxy- ethoxy)-3,5-di(dibenzo[b,d]thien-4-yl)phenyl]sulfonyl-2,6-dibenzo[b,d]thien-4-yl)phe- noxy]ethanol and the like. Among the monomers of the general formula (IV) or of formulae (IV-1) to (IV-8), par- ticular preference is given to the monomers of formulae (IV-1), (IV-2), (IV-3) and (IV- 8), even more preference is given to the monomers of formulae (IV-11), (IV-12), (IV- 13), (IV-14), (IV-15), (IV-21) and (IV-22), and special preference given to 2,2'-bis(2- hydroxyethoxy)-1,1'-binaphthyl (BNE or BHBNA), 2,2'-bis(2-hydroxyethoxy)-6,6’-diphe- nyl-1,1'-binaphthyl (DPBHBNA), 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF), 9,9-bis(6-(2-hydroxyethoxy)-2-naphthyl)fluorene (BNEF), 9,9-bis(4-(2-hydroxyethoxy)- 3-phenylphenyl)fluorene (BPPEF), 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-di(phenanthren-9- yl)-phenyl]-1-methylethyl]-2,6-di(phenanthren-9-yl)-phenoxy]ethanol, 2-[4-[1-[4-(2- hydroxyethoxy)-3,5-di(1,2-dibenzo[b,d]thien-4-yl)-phenyl]-1-methyl-ethyl]-2,6-di(1,2- dibenzo[b,d]thien-4-yl)-phenoxy]ethanol, 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-di(thi- antren-1-yl)-phenyl]-1-methyl-ethyl]-2,6-di(thianthren-1-yl)-phenoxy]ethanol, 2-[4-[4- (2-hydroxyethoxy)-3,5-di(phenanthren-9-yl)phenyl]sulfonyl-2,6-di(phenanthren-9-yl)- phenoxy]ethanol, 2-[4-[4-(2-hydroxyethoxy)-3,5-di(thianthrene-1-yl)phenyl]sulfonyl- 2,6-di(thianthrene-1-yl)phenoxy]ethanol and 2-[4-[4-(2-hydroxyethoxy)-3,5- di(dibenzo[b,d]thien-4-yl)phenyl]sulfonyl-2,6-dibenzo[b,d]thien-4-yl)phenoxy]ethanol. Accordingly, amongst the structural units of formula (V) that may be comprised in the thermoplastic resin preference is given to structural units of the general formulae (V-1) to (V-8), M / REUCTR-054-PC 46 where M / REUCTR-054-PC 47 a and b are 0, 1, 2 or 3, in particular 0 or 1; a’ and b’ are 0, 1, 2 or 3, in particular 0 or 1; c and d are 0, 1, 2, 3, 4 or 5, in particular 0 or 1; e and f are 0, 1, 2, 3, 4 or 5, in particular 0 or 1; W’ is S, S(O), SO2, O, single bond, CH2, CH(CH3), C(CH3)2, in particular S, S(O), SO2or C(CH3)2; and where Rz, Raa, Rab, R7a, R7band L are as defined for formula (V) and where Rzis in particular selected from a single bond, CH2and OCH2CH2. Particular preference is given to structural units of the general formulae (V-11) to (V- 22), where Rzand Raaare as defined herein and where Rzis in particular selected from a single bond, CH2and O-CH2CH2, and especially is O-CH2CH2: M / REUCTR-054-PC 48 Among the structural units of the formulae (V-1) to (V-8), particular preference is given to the structural units of formulae (V-1), (V-2), (V-3) and (V-8). Among the structural units of the formulae (V-11) to (V-22), particular preference is given to the structural units of formulae (V-11), (V-12), (V-13), (V-14), (V-15), (V-21) and (V-22), and special preference given to structural units derived from 2,2'-bis(2-hydroxyeth- oxy)-1,1'-binaphthyl (BNE or BHBNA), 2,2'-bis(2-hydroxyethoxy)-6,6’-diphenyl-1,1'- binaphthyl (DPBHBNA), 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BPEF), 9,9-bis(6- (2-hydroxyethoxy)naphthalene-2-yl)fluorene (BNEF), 9,9-bis(4-(2-hydroxyethoxy)-3- phenylphenyl)fluorene (BPPEF), 2-[4-[4-(2-hydroxyethoxy)-3,5-di(thianthrene-1- yl)phenyl]sulfonyl-2,6-di(thianthrene-1-yl)phenoxy]ethanol, 2-[4-[4-(2-hydroxyethoxy)- 3,5-di(phenanthren-9-yl)phenyl]sulfonyl-2,6-di(phenanthren-9-yl)-phenoxy]ethanol, 2- [4-[4-(2-hydroxyethoxy)-3,5-di(dibenzo[b,d]thien-4-yl)phenyl]sulfonyl-2,6- dibenzo[b,d]thien-4-yl)phenoxy]ethanol, 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-di(phenan- thren-9-yl)-phenyl]-1-methylethyl]-2,6-di(phenanthren-9-yl)-phenoxy]ethanol, 2-[4-[1- M / REUCTR-054-PC 49 [4-(2-hydroxyethoxy)-3,5-di(1,2-dibenzo[b,d]thien-4-yl)-phenyl]-1-methyl-ethyl]-2,6- di(1,2-dibenzo[b,d]thien-4-yl)-phenoxy]ethanol and 2-[4-[1-[4-(2-hydroxyethoxy)-3,5- di(thiantren-1-yl)-phenyl]-1-methyl-ethyl]-2,6-di(thianthren-1-yl)-phenoxy]ethanol. In a particular preferred group of embodiments, the thermoplastic resin of the present invention comprises at least one structural unit of the formulae (II-1), (II-2) and / or (II- 3) and at least one structural unit selected from the group consisting of structural units of the formula (V-11), structural units of the formula (V-12), structural units of the for- mula (V-13), structural units of the formula (V-14), structural units of the formula (V- 15), structural units of the formula (V-21) and structural units of the formula (V-22). In this particular group of embodiments, those thermoplastic resins are preferred, where in the structural units of the formulae (V-11), (V-12), (V-13), (V-14), (V-15), (V-21) and (V-22) the radicals Rzare O-CH2CH2. In the thermoplastic resins of this particular preferred group of embodiments, it is pre- ferred that the total molar ratio of the structural units of the formulae (II-1), (II-2) and / or (II-3), herein also called the structural units of formula (II), is in the range from 1 to 99 mol-%, preferably in the range from 5 to 98 mol-%, further preferably in the range from 10 to 97 mol-%, and even further preferably in the range from 20 to 95 mol-% of the total amount of structural units of the formula (II) and (V). The compounds of the formulae (IV), (IV-1), (IV-2), (IV-3), (IV-4), (IV-5), (IV-6), (IV- 7), (IV-8), (IV-11), (IV-12), (IV-13), (IV-14), (IV-15), (IV-16), (IV-17), (IV-18), (IV- 19), (IV-20), (IV-21) and (IV-22) are known or can be prepared by analogy to known methods. For example, the compounds of the formula (IV-8) can be prepared by various synthe- sis methods, as disclosed e.g. in JP Publication No. 2014-227387, JP Publication No. 2014-227388, JP Publication No. 2015-168658, and JP Publication No. 2015-187098. For example, 1,1’-binaphthols may be reacted with ethylene glycol monotosylates; al- ternatively, 1,1’-binaphthols may be reacted with alkylene oxides, halogenoalkanols, or alkylene carbonates; and alternatively, 1,1’-binaphthols may be reacted with ethylene carbonates. Thereby, the compounds of the formula (IV-8) are obtained, where Rz-OH is O-Alk2- or O-Alk2-[O-Alk2-]p-. For example, the compounds of the formula (IV-2) can be prepared by various synthe- sis methods, as disclosed e.g. in JP Patent Publication No. 5442800, and JP Publication No. 2014-028806. Examples include: (a) reacting fluorenes with hydroxy naphthalenes in the presence of hydrochloride gas and mercapto-carboxylic acid; (b) reacting 9-fluorene with hydroxy naphthalenes in the presence of acid catalyst (and alkyl mercaptan); M / REUCTR-054-PC 50 (c) reacting fluorenes with hydroxy naphthalenes in the presence of hydrochloride and thiols (such as, mercapto-carboxylic acid); (d) reacting fluorenes with hydroxy naphthalenes in the presence of sulfuric acid and thiols (such as, mercapto-carboxylic acid) and thereafter to crystallize the product from a crystallization solvent which consists of hydrocarbons and a polar solvent(s) to form bisnaphthol fluorene; and the like. Thereby, compounds of the formula (IV-2) can be obtained, where Rzis a single bond. The compounds of formulae (IV), where Rzis O-Alk2- or O-Alk2-[O-Alk2-]p- can be pre- pared from compounds of formulae (IV), where Rzis a single bond, by reaction with al- kylene oxides or haloalkanols. For example, reacting 9,9-bis(hydroxynaphthyl)-fluo- renes of the formula (IV-2) where Rzis a single bond with alkylene oxides or haloalka- nols results in the compounds of the formula (IV-2) where Rzis O-Alk2- or O-Alk2-[O- Alk2-]p-. For example, 9,9-bis[6-(2-hydroxyethoxy)naphthyl] fluorene can be prepared by reacting 9,9-bis[6-(2-hydroxynaphthyl] fluorene with 2-chloroethanol under alkaline conditions. The monomers of formulae (VI-1), (VI-2) and or (VI-3), herein also called monomers of formula (VI), and likewise the co-monomers of formula (IV) used for producing the thermoplastic resin may contain impurities resulting from their preparation, e.g. hy- droxy compounds, which bear an OH group instead of e.g. a group O-CH2CH2-OH. The total amount of such impurity compounds is preferably 5000 ppm or lower, more pref- erably 3000 ppm or lower, still more preferably 2000 ppm or lower, and especially preferably 1000 ppm or lower. The total content of the impurities in the monomers used for preparing the thermoplastic resin is preferably 4000 ppm or lower in particular 1500 ppm or lower, and more preferably 1000 ppm or lower, and even more prefera- bly 500 ppm or lower. Likewise, the amount of impurities in the co-monomers of for- mula (IV) will be in the range given for the monomers of formula (VI). Suitable resin compositions of the present invention for the preparation of optical de- vices, such as lenses comprise thermoplastic resins, that are in particular polycar- bonates, polyestercarbonates and polyesters. Preferred resin compositions for the preparation of optical devices, such as lenses, comprise thermoplastic resins that are in particular polycarbonates. Said polycarbonates are structurally characterized by having structural units of at least one of the formulae (II-1), (II-2) and (II-3), respectively, optionally structural units de- rived from diol monomers, which are different from the monomer compound of the for- mula (VI), e.g. structural units of the formula (V), #-O-Rz-A3-Rz-O-# (V) M / REUCTR-054-PC 51 where #, Rzand A3are as defined herein above; and a structural unit of formula (III-1) stemming from the carbonate forming compo- nent: (III-1) where each # represents a connection point to a neighboring structural unit, i.e. usu- ally to O at the connection point of the structural unit of the formula (II) and, if pre- sent, to O at the connection point of the structural unit of the formula (V). Said polyesters are structurally characterized by having structural units of at least one of the formulae (II-1), (II-2) and (II-3), respectively, optionally structural units derived from diol monomers which are different from the monomer compound of the formula (VI), e.g. structural units of the formula V. If A1a, A2a, A1b, A2c, A1cand A2cin formulae (II-1), (II-2) and / or (II-3) are selected from O and in the case of A1cand A2calso CH2O, the polyesters may have structural units derived from one or more dicarboxylic acids, e.g. of formula (III-2) in case of a benzene dicarboxylic acid, of formula (III-3) in case of a naphthalene carboxylic acid, of formula (III-4) in case of oxalic acid and of formula (III-5) in case of malonic acid: In formula (III-2) to (III-5) each variable # represents a connection point to a neigh- boring structural unit, i.e. typically to O of the connection point of the structural unit of the formula (II) and, if present, to O of the connection point of the structural unit of the formula (V). Said polyestercarbonates are structurally characterized by having structural units of at least one of the formulae (II-1), (II-2) and (II-3), respectively, optionally structural units derived from diol monomers which are different from the monomer compound of the formula (VI), e.g. structural units of the formula (V), a structural unit of formula (III-1) stemming from the carbonate forming component and structural units derived from dicarboxylic acid, e.g. of formula (III-2) in case of a benzene dicarboxylic acid, of M / REUCTR-054-PC 52 formula (III-3) in case of a naphthalene carboxylic acid, of formula (III-4) in case of oxalic acid and of formula (III-5) in case of malonic acid. A particular group of embodiments relates to resin compositions comprising thermo- plastic copolymer resins, such as in particular polycarbonates, polyestercarbonates and polyesters, which have both structural units of formula (II), i.e. structural units of for- mula (II-1), (II-2) or (II-3), and one or more structural units of formula (V), i.e. resins, in particular polycarbonates, polyestercarbonates and polyesters, which are obtainable by reacting at least one monomer of formula (VI) with one or more monomers of for- mula (IV). In this case the molar ratio of monomers of formula (VI) to monomers of formula (IV) and likewise the molar ratio of the structural units of formula (II) to struc- tural units of formula (V) are in the range from 1:99 to 99:1, in particular in the range from 10:90 to 99:1 and especially in the range from 15:85 to 97:3. Accordingly, the molar ratio of the structural units of the formula (II) is usually from 1 to 99 mol-% in particular from 10 to 99 mol-%, and specifically in range from 15 to 97 mol-%, based on the total molar amount of structural units of the formulae (II) and (V). Accordingly, the molar ratio of the structural units of the formula (V) is usually from 1 to 99 mol-%, in particular from 1 to 90 mol-%, especially in the range from 3 to 85 mol-% based on the total molar amount of structural units of the formulae (II) and (V). The above- mentioned molar ratios can be applied to the molar ratio of the structural units of for- mula (II) to the total structural units of the thermoplastic copolymer resins. A specific group of embodiments relates to resin compositions comprising thermo- plastic copolymer resins, such as in particular polycarbonates, polyestercarbonates and polyesters, which have both structural units of formula (II) and one or more structural units of formulae (V-11), (V-12), (V-13), (V-14), (V-15), (V-21) or (V-22), i.e. resins, in particular polycarbonates, polyestercarbonates and polyesters, which are obtainable by reacting at least one monomer of formula (VI) with one or more monomers of formu- lae (IV-11), (IV-12), (IV-13), (IV-14), (IV-15), (IV-21) or (IV-22). In this case the mo- lar ratio of monomers of formula (VI) to monomers of formulae (IV-11), (IV-12), (IV- 13), (IV-14), (IV-15), (IV-21) and (IV-22) and likewise the molar ratio of the structural units of formula (II) to structural units of formulae (V-11), (V-12), (V-13), (V-14), (V- 15), (V-21) and (V-22) are in the range from 1:99 to 99:1, in particular in the range from 10:90 to 99:1, and especially in the range from 15:85 to 97:3. The above-men- tioned molar ratios can be applied to the molar ratio of the structural units of formula (II) to the total structural units of the thermoplastic copolymer resins. The thermoplastic copolymer resins contained in the resin compostions of the present invention, such as a polycarbonate resin, may include either one of a random copoly- mer structure, a block copolymer structure, and an alternating copolymer structure. The thermoplastic resin contained in a resin composition according to the present in- vention does not need to include one or more of structural units (II) and one or more M / REUCTR-054-PC 53 different structural units (V) in one, same polymer molecule. Namely, the thermoplastic copolymer resin according to the present invention may be a blend resin as long as the above-described structures are each included in any of a plurality of polymer mole- cules. For example, the thermoplastic resin including structural units (II) and structural units (V) described above may be a mixture of a homopolymer or a copolymer includ- ing at least one structural unit (II) and a homopolymer or a copolymer including at least one structural unit (V) or it may be a blend resin of a copolymer including at least one structural unit (II) and a first structural unit (V) and a copolymer including at least one structural unit (II) and at least one other structural unit (V) different from the first structural units (V); etc. Thermoplastic polycarbonates are obtainable by polycondensation of a diol component and a carbonate forming component. Similarly, thermoplastic polyesters and polyester- carbonates are obtainable by polycondensation of a diol component and a dicarboxylic acid, or an ester forming derivative thereof, and optionally a carbonate forming compo- nent. Specifically, thermoplastic resins (polycarbonate resins) can be prepared by the follow- ing methods. A method for preparing the thermoplastic resin preferably contained in the resin com- positions of the present invention, such as a polycarbonate resin, includes a process of melt polycondensation of a dihydroxy component corresponding to the above-men- tioned structural units and a diester carbonate. The dihydroxy compound preferably comprises at least one dihydroxy compound represented by the formula (VI), in partic- ular by at least one of formulae (VI-1), (VI-2) or (VI-3), as defined herein. In addition to the compound of formula (VI), the dihydroxy compound may also comprise one or more dihydroxy compounds represented by the formula (IV), preferably by the formu- lae (IV-1) to (IV-8), in particular by the formulae (IV-11) to (IV-22), and especially by the formulae (IV-11), (IV-12), (IV-13), (IV-14), (IV-15), (IV-21) or (IV-22). As is clear from the above, the polycarbonate resin can be formed by reacting a dihy- droxy component with a carbonate precursor, such as a diester carbonate, where the dihydroxy component preferably comprises at least one compound represented by the formulae (VI-1), (VI-2) and (VI-3), respectively, or a combination of at least one com- pound represented by the formulae ((VI-1), (VI-2) and (VI-3), respectively, and at least one compound represented by the formulae (IV), (IV-1), (IV-2), (IV-3), (IV-4), (IV-5), (IV-6), (IV-7), (IV-8), (IV-11), (IV-12), (IV-13), (IV-14), (IV-15), (IV-16), (IV- 17), (IV-18), (IV-19), (IV-20), (IV-21) or (IV-22). Specifically, a polycarbonate resin can be formed by a melt polycondensation process in which the compound represented by the formulae (VI-1), (VI-2) and (VI-3), respectively, or a combination thereof with at least one compound of the formulae (IV), (IV-1), (IV-2), (IV-3), (IV-4), (IV-5), (IV- M / REUCTR-054-PC 54 6), (IV-7), (IV-8), (IV-11), (IV-12), (IV-13), (IV-14), (IV-15), (IV-16), (IV-17), (IV-18), (IV-19), (IV-20), (IV-21) or (IV-22) and a carbonate precursor, such as a diester car- bonate, are reacted in the presence of a basic compound catalyst, a transesterification catalyst, or a mixed catalyst thereof, or in the absence of a catalyst. A thermoplastic resin (or a polymer) other than a polycarbonate resin, such as polyes- tercarbonates and polyesters is preferably obtained by using the dihydroxy compound represented by the formulae (VI-1), (VI-2) and (VI-3), respectively, or a combination thereof with at least one compound represented by the formulae (IV), (IV-1), (IV-2), (IV-3), (IV-4-), (IV-5), (IV-6), (IV-7), (IV-8), (IV-11), (IV-12), (IV-13), (IV-14), (IV-15), (IV-16), (IV-17), (IV-18), (IV-19), (IV-20), (IV-21) or (IV-22) as a material (or a mono- mer). As mentioned before, the monomers of formula (VI) and likewise the co-monomers of formula (IV) used for producing the thermoplastic resin may contain impurities result- ing from their preparation. For example, the monomers of the formulae (IV-1) and (IV-2), where Rzis O-Alk2- or O-Alk2-[O-Alk2-]p-, may include a dihydroxy compound in which both Rzare a single bond, or a dihydroxy compound in which one of Rzis a single bond, instead of O-Alk2- or O-Alk2-[O-Alk2-]p-. The total amount of such dihydroxy compounds of the formulae (IV-1) or (IV-2) in which at least one of Rzdiffers from O-Alk4- or O-Alk4-[O-Alk4-]w-, is preferably 3000 ppm or lower, more preferably 1500 ppm or lower, still more preferably 1000 ppm or lower, and especially preferably 500 ppm or lower; in the monomer(s) of which main component is the dihydroxy compound(s) represented by the formulae (IV- 1) or (IV-2). The total content of the dihydroxy compounds in which at least one of the values of a and b or c and d differs from the formula (IV-1) or (IV-2) is still preferably 300 ppm or lower, and more preferably 200 ppm or lower. The polycarbonate resins can be obtained by reacting the monomer compounds of the formula (VI) or by reacting combination of at least one monomer compound of the for- mula (VI), in particular at least one monomer (VI) mentioned herein as preferred, and one or more monomer compounds of the formula (IV), and in particular of the formu- lae (IV-11), (IV-12), (IV-13), (IV-14), (IV-15), IV-21) or (IV-22), and the like, as dihy- droxy components; with carbonate precursors, such as diester carbonates. However, in a polymerization process for manufacturing the polycarbonate resins, some compounds of the formulae (VI) and (IV) may be converted into impurities, where terminal groups OCH2CH2OH, if present, are replaced with a different radical, such as a vinyl terminal radical represented by -OCH=CH2. Because the amount of M / REUCTR-054-PC 55 such impurities is generally small, the products of the formed polymers can be used as polycarbonate resins without a purification process. The thermoplastic resin contained in the resin composition of the present invention may also contain minor amount of impurities, for example, as extra contents of ther- moplastic resin composition or a part of the polymer skeleton of the thermoplastic resin. The examples of such impurities include phenols formed by a process for form- ing the thermoplastic resin, unreacted diester carbonates and monomers. The total amount of impurities in the thermoplastic resin may be 5000 ppm or lower, or 2000 ppm or lower. The total amount of impurities in the thermoplastic resin is prefer- ably 1000 ppm or lower, more preferably 500 ppm or lower, still more preferably 200 ppm or lower, and especially preferably 100 ppm or lower. The total amount of phenols as impurities in the thermoplastic resin may be 3000 ppm or lower, or 2000 ppm or lower. The total amount of phenols as impurities is prefera- bly 1000 ppm or lower, more preferably 800 ppm or lower, still more preferably 500 ppm or lower, and especially preferably 300 ppm or lower. The total amount of diester carbonates as impurities in the thermoplastic resin is pref- erably 1000 ppm or lower, more preferably 500 ppm or lower, still more preferably 100 ppm or lower, and especially preferably 50 ppm or lower. The total amount of unreacted monomers as impurities in the thermoplastic resin is preferably 3000 ppm or lower, more preferably 2000 ppm or lower, still more prefera- bly 1000 ppm or lower, and especially preferably 500 ppm or lower. The lower limit of the total amount of these impurities is not important, but may be 0.1 ppm, or 1.0 ppm. The total amount of residual heavy metals, e.g. palladium, as impurity in the thermo- plastic resin is preferably 50 ppm or lower, more preferably 10 ppm or lower. The amount of residual palladium can be reduced by standard procedures like treatment with an adsorbent, e.g. active charcoal. Thermoplastic resins having targeted characteristics can be formed by adjusting the amounts of phenols and diester carbonates. The amounts of phenols, diester car- bonates, and monomers can be suitably adjusted by arranging the conditions for poly- condensation, the working conditions of devices used for polymerization, or the condi- tions for extrusion molding after the polycondensation process. The weight-average molecular weight (Mw), as determined by GPC (gel permeation chromatography), of the resin, in particular the thermoplastic resin, contained in the resin composition according to the present invention is preferably in the range from 5000 to 100000 Dalton, more preferably 10000 to 80000 Dalton or 20000 to 65000 Dalton, especially in the range of 10000 to 50000 Dalton or 20000 to 40000 Dalton. M / REUCTR-054-PC 56 The GPC measurments may be calibrated by using polystyrene standards. The Mw of a thermoplastic resin determined this way is also denoted herein as “polystyrene conver- sion weight-average molecular weight”. The number-average molecular weight (Mn) of the thermoplastic resin contained in the resin according to the present invention is preferably in the range of 3000 to 30000, more preferably 5000 to 25000, and espe- cially in the range of 7000 to 20000. The viscosity-average molecular weight (Mv) of the thermoplastic resin according to the present invention is preferably in the range from 8000 to 28000, more preferably 9000 to 22000, and still more preferably 10000 to 18000. The value of the molecular weight distribution (Mw / Mn) of the thermoplastic resin con- tained in the resin compositon according to the present invention is preferably 1.5 to 9.0, more preferably 1.8 to 7.0, and still more preferably 2.0 to 4.0. The resin composition according to the present invention can be prepared by mixing at least one compound of formulae (I), (Ia) or (Ib) with thermoplastic resin, such as in particular at least one of the thermoplastic resins described herein as preferred. Mixing is preferably continued until a homogenous or almost homogenous compositon is ob- tained. In order to accomplish sufficient mixing procedures known in the art for similar purposes can be used. Preferably, the mixing is accomplised by adding at least one compound of formulae (I), (Ia) or (Ib) and at least one thermoplastic resin into a suita- ble reactor and agitating this combination at an elevated temperature of from 100 to 350°C, preferably 200 to 300°C, in particular 240 to 290°C, and specifically 250 to 280°C over to a period of time to obtain at least almost homogeneous blend. During this mixing procedure the pressure in the reactor may be kept close to the atmospheric pressure, i.e. in range of about 80 to 120 kPa. Alternatively the pressure within the re- actor may also me reduced to below 50 kPa, preferably to below 40 or 30 kPa, such as to pressure of 5 to 50 kPa, preferably 10 to 40 kPa and especially 15 to 30 kPa. The resin composition according to the present invention preferably comprises 5 to 50 % by weight, in particular 10 to 40 % by weight and especially 15 to 30 % by weight, 18 to 27 % by weight, 20 to 25 % by weight or 22 to 27 % by weight of at least one compound of formulae (I), (Ia) or (Ib), and accordingly 50 to 95 % by weight, in particular 60 to 90 % by weight and especially 70 to 85 % by weight, 73 to 82 % by weight, 75 to 80 % by weight or 73 to 78 % by weight of thermoplastic resin, such as in particular one of the thermoplastic resin described herein as preferred. Thus, in order to obtain a resin composition of the present invention containing the at least one compound of formulae (I), (Ia) or (Ib) and the at least one thermoplastic resin in the above preferred weight ratios, the two components have to be mixed in corresponding amounts. M / REUCTR-054-PC 57 Preferably, the thermoplastic resin contained in the resin compositon of the invention comprises 9% by weight or less, in particular 7% by weight or less and especially 5% by weight or less, e. g. 0.1 to 9% by weight, in particular 0.1 to 7% by weight and es- pecially 0.1 to 5% by weight, of low molecular weight compounds having molecular weight of less than 1000, based on the total weight of the thermoplastic resin, where the low molecular weight compounds are different from compounds of formulae (I), (Ia) and (Ib). If such low molecular weight compounds are present in the thermo- plastic resin in an amount within the above ranges, the mechanical strength of a molded body made from the resin composition containing the thermoplastic resin is commonly increased, especially compared to a molded body made from a resin compo- sition comprising thermoplastic resin with a higher amount of the low molecular weight compounds. The resin compositions of the present invention, such as especially those containing the above-mentioned polycarbonate resins, have a high refractive index (nDor nd) and thus are suitable to an optical lens. The values of the refractive index as referred herein are values of a film having a thickness of 0.1 mm may be measured by use of an Abbe refractive index meter by a method of JIS-K-7142. The refractive index of the resin compositions of the present invention, in particular those containing a polycar- bonate resin of the present invention, at 23°C and at a wavelength of 589 nm is, espe- cially in case the resin includes a structural unit (II), frequently 1.640 or higher, prefer- ably 1.650 or higher, more preferably 1.660 or higher, still more preferably 1.670 or higher, in particular 1.680 or higher, 1.685 or higher, or 1.690 or higher, and specifi- cally 1.695 or higher. For example, the refractive index of the resin composition com- prising a compound of formula (I) as additive and a copolycarbonate resin including at one or more of the the structural units (II) and optionally a structural unit (V) as de- scribed above is typically 1.640 to 1.730, preferably 1.650 to 1.730, preferably 1.660 to 1.730, still more preferably 1.670 to 1.730 or 1.680 to 1.730. The refractive index of the resin composition according to the present invention is typi- cally 0.001 or more, preferably 0.01 or more, in particular 0.05 or more, and specifi- cally 0.1 or more higher than that of a reference resin composition having the same composition but without the compounds of formulae (I), (Ia) or (Ib), where the refer- ence resin usually corresponds to the thermoplastic resin contained in the resin compo- sition. The Abbe number (^ or ^d) of the resin composition of the present invention, such as especially those containing the above-mentioned polycarbonate resins, is typically 24 or lower, preferably 22 or lower, more preferably 20 or lower, even more preferably 19 or lower, and still more preferably 18 or lower, or 18.5 or lower, and specifically 17 or lower, or 17.5 or lower. The Abbe number may be calculated by use of the following M / REUCTR-054-PC 58 equation based on the refractive index at wavelengths of 487 nm, 589 nm and 656 nm at 23°C: ^ = (nD - 1) / (nF - nC) nD: refractive index at a wavelength of 589 nm nC: refractive index at a wavelength of 656 nm nF: refractive index at a wavelength of 486 nm The Abbe number of the resin composition according to the present invention is typi- cally 0.05 or more, preferably 0.1 or more, more preferably 0.15 or more, in particular 0.2 or more, and specifically 0.25 ore more lower than that of a reference resin compo- sition having the same composition but without the compounds of formulae (I), (Ia) or (Ib), where the reference resin usually corresponds to the thermoplastic resin con- tained in the resin composition. The glass transition temperature (Tg) of the resin composition of the present inven- tion, such as especially one containing a polycarbonate resin as mentioned above, is, in consideration of that the composition is usable for injection molding, frequently in the range of 90 to 185°C, preferably in the range of 90 to 150°C, more preferably in the range of 90 to 140°C, even more preferably in the range of 90 to 135°C or 95 to 135°C. With regard to the molding fluidity and the molding heat resistance, the lower limit of Tg is preferably 105°C and more preferably 110°C, and the upper limit of Tg is preferably 160°C and more preferably 140°C. A glass transition temperature (Tg) in the above given ranges provides a significant range of usable temperature and avoids the risk that the melting temperature of the resin composition may be too high, and thus the resin may be undesirably decomposed or colored. What is more, it allows for preparing molds having have a high surface accuracy. The values given for the glass transition temperature refer to the values measured by differential scanning calorime- try (DSC) using a 10°C / minute heating program according to the protocol of JIS K7121-1987. The glass transition temperature (Tg) of the resin composition according to the present invention is typically 5(°C) or more, preferably 10(°C) or more, more preferably 15(°C) or more, in particular 20(°C) or more, and specifically 25(°C) ore more lower than that of a reference resin composition having the same composition but without the com- pounds of formulae (I), (Ia) or (Ib), where the reference resin usually corresponds to the thermoplastic resin contained in the resin composition. An optical molded body such as an optical element produced by using a resin composi- tion of the present invention has a total light transmittance of preferably 85% or M / REUCTR-054-PC 59 higher, more preferably 87% or higher, and especially preferably 88% or higher. A to- tal light transmittance of preferably 85% or higher is as good as that provided by bi- sphenol A type polycarbonate resin or the like. The resin composition according to the present invention has high moisture and heat resistance. The moisture and heat resistance may be evaluated by performing a "PCT test" (pressure cooker test) on a molded body such as an optical element produced by use of the resin composition and then measuring the total light transmittance of the molded body after the PCT test. In the PCT test, first, an injection molded body having a diameter of 50 mm and a thickness of 3 mm is kept for 20 hours with PC305S III made by HIRAYAMA Corporation under the conditions of 120°C, 0.2 MPa, 100%RH for 20 hours. Then, the sample of the injection molded body is removed from the device and the total light transmittance is measured using the SE2000 type spectroscopic par- allax measuring instrument made by Nippon Denshoku Industries Co., Ltd in accord- ance with the method of JIS-K-7361-1. The resin composition according to the present invention has a post-PCT test total light transmittance of 60% or higher, preferably 70% or higher, more preferably 75% or higher, still more preferably 80% or higher, and especially preferably 85% or higher. As long as the total light transmittance is 60% or higher, the resin composition is con- sidered to have a higher moisture and heat resistance than that of the conventional thermoplastic resin. The resin composition according to the present invention has a b value, which repre- sents the hue, of preferably 5 or lower. As the b value is smaller, the color is less yel- lowish, which is good as a hue. According to the invention, the diol component, which is used in the preparation of the polycarbonates or polyesters contained in the resin composition, may additionally com- prise one or more diol monomers, which are different from the monomer compound of the formula (VI), such as one or more monomers of the formula (IV). Suitable diol monomers, which are different from the monomer compound of the for- mula (VI), are those, which are conventionally used in the preparation of polycar- bonates, e.g. - aliphatic diols such as ethylene glycol, propanediol, butanediol, pentanediol and hexanediol; - alicyclic diols such as tricyclo[5.2.1.02,6]decane dimethanol, cyclohexane-1,4-di- methanol, decalin-2,6-dimethanol, norbornane dimethanol, pentacyclopentadecane dimethanol, cyclopentane-1,3-dimethanol, spiroglycol, 1,4:3,6-dianhydro-D-sorbi- tol, 1,4:3,6-dianhydro-D-mannitol and 1,4:3,6-dianhydro-L-iditol are also included in examples of the diol; and M / REUCTR-054-PC 60 - aromatic diols, in particular aromatic diols of the formula (IV) such as bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, bis(4-hydroxy- phenyl)ether, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfide, bis(4- hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)ketone, 2,2-bis(4-hydroxyphenyl)pro- pane, 2,2-bis(4-hydroxy-3-t-butylphenyl)propane, 2,2-bis(4-hydroxy-3- methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxy- phenyl)cyclohexane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxy- phenyl)diphenylmethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, α,ω-bis[2-(p- hydroxyphenyl)ethyl]polydimethylsiloxane, α,ω-bis[3-(o-hydroxyphenyl)propyl]pol- ydimethylsiloxane, 4,4’-[1,3-phenylenebis(1-methylethylidene)hydroxyphenyl]-1- phenylethane, 10,10-bis(4-hydroxyphenyl)anthracen-9-on, 10,10-bis(4-(2-hydroxy- ethyl)phenyl)anthracen-9-on, 2-[4-[4-(2-hydroxyethoxy)-3,5-di(thianthrene-1- yl)phenyl]sulfonyl-2,6-di(thianthrene-1-yl)phenoxy]ethanol, 2-[4-[4-(2-hydroxyeth- oxy)-3,5-di(dibenzo[b,d]thien-4-yl)phenyl]sulfonyl-2,6-dibenzo[b,d]thien-4-yl)phe- noxy]ethanol and 2-[4-[1-[4-(2-hydroxyethoxy)-3,5-di(phenanthren-9-yl)-phenyl]- 1-methylethyl]-2,6-di(phenanthren-9-yl)-phenoxy]ethanol. Frequently, the relative amount of monomer compound of formula (VI), based on the total weight of the diol component, is at least 30 % by weight, preferably at least 50% or at least 70% by weight, in particular at least 85% by weight, especially at least 95% by weightor at leats 99 % by weight, typically in the range of 30 to 100% by weight, preferably in the range of 50 to 100% by weight, in particular in the range of 70 to 100% by weight, especially in the range of 85 to 100% by weight, specifically in the range of 90 to 100% by weight or even 95 to 100% by weight. Consequently, the relative molar amount of monomer compound of formula (IV), based on the total molar amount of the diol component, will not exceed 70 mol-% or 50 mol-% or 30 mol-%, in particular not exceed 15 mol-% and especially not exceed 5 mol-% or 1 mol-%, and is preferably in the range of 0 to 70 mol-% or in the range of 0 to 50 mol-% or in the range of 0 to 30 mol-% or in the range of 0 to 15 mol-%, in particular in the range of 0 to 5 mol-% or in the range of 0 to 1 mol-%. Frequently, the total molar amount of monomers of formula (VI) and monomers of for- mula (IV) is at least 80 mol-%, in particular at least 90 mol-%, especially at least 95 mol-% or up to 100 mol-%, based on the total molar amount of the diol monomers in the diol component. Examples of further preferred aromatic dihydroxy compound, which can be used in ad- dition to the monomers of formula (I) and optionally monomers of formula (IV) in- M / REUCTR-054-PC 61 clude, but are not limited to bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bi- sphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol Z and the like. In order to adjust the molecular weight and the melt viscosity, the monomers forming the thermoplastic polymer contained in the resin composition of the present invention may also include a monofunctional compound, in case of polycarbonates a monofunc- tional alcohol and in case of polyesters a monofunctional alcohol or a monofunctional carboxylic acid. Suitable monoalcohols are butanol, hexanol and octanol. Suitable mon- ocarboxylic acids include e.g. benzoic acid, propionic acid and butyric acid. In order to increase the molecular weight and the melt viscosity, the monomers forming the ther- moplastic polymer may also include a polyfunctional compound, in case of polycar- bonates a polyfunctional alcohol having three or more hydroxyl groups and in case of polyesters a polyfunctional alcohol having three or more hydroxyl groups or a polyfunc- tional carboxylic acid having three or more carboxyl groups. Suitable polyfunctional al- cohols are e.g. glycerine, trimethylol propane, pentaerythrit and 1,3,5-trihydroxy pen- tane. Suitable polyfunctional carboxylic acids having three or more carboxyl groups are e.g. trimellitic acid and pyromellitic acid. The total amount of these compounds, will frequently not exceed 10 mol-%, based on the molar amount of the diol component. Suitable carbonate forming monomers, are those, which are conventionally used as carbonate forming monomers in the preparation of polycarbonates, include, but are not limited to phosgene, diphosgene and diester carbonates such as diethyl carbonate, diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate and dinaphthyl carbonate. Out of these, diphenyl carbonate is particularly preferred. The carbonate forming monomer is frequently used at a ratio of 0.97 to 1.20 mol, and more preferably 0.98 to 1.10 mol, with respect to 1 mol of the dihydroxy compound(s) in total. Suitable dicarboxylic acids include, but are not limited to - aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid; - alicyclic dicarboxylic acids such as tricyclo[5.2.1.02,6]decane dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, decalin-2,6-dicarboxylic acid, and norbornandi- carboxylic acid; and - aromatic dicarboxylic acids, such as benzene dicarboxylic acids, specifically phthalic acid, isophthalic acid, 2-methylterephthalic acid or terephthalic acid, and naphthalene dicarboxylic acids, specifically naphthalene-1,3-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene- 1,6-dicarboxylic acid, naphthalene-1,7-dicarboxylic acid, naphthalene-2,5-dicarbox- ylic acid, naphthalene-2,6-dicarboxylic acid, 2-[9-(carboxymethyl)fluoren-9-yl]ace- tic acid (formula DC1), 2-[9-(carboxymethyl)fluoren-9-yl]propionic acid (formula M / REUCTR-054-PC 62 DC2), 2,2’-bis(carboxymethyloxy)-1,1’-binaphthyl (formula DC3) and naphthalene-2,7-dicarboxylic acid. Suitable ester forming derivatives of dicarboxylic acids include, but are not limited to the dialkyl esters, the diphenyl esters and the ditolyl esters. In case of polyesters, the ester forming monomer is frequently used at a ratio of 0.97 to 1.20 mol, and more preferably 0.98 to 1.10 mol, with respect to 1 mol of the dihy- droxy compound(s) in total. The polycarbonates contained in resin composition of the present invention can be pre- pared by reacting a diol component comprising a monomer of formula (VI) and option- ally a further diol monomer such as a monomer of the formula (IV) and a carbonate forming monomer by analogy to the well known preparation of polycarbonates as de- scribed e.g. in US 9,360,593, US 2016 / 0319069 and US 2017 / 0276837, to which full reference is made. The polyesters contained in resin composition of the present invention can be prepared by reacting a diol component comprising a monomer of formula (VI) and optionally a further diol monomer such as a monomer of the formula (IV) and a dicarboxylic acid or its ester forming derivative by analogy to the well known preparation of polyesters as described e.g. in US 2017 / 044311 and the references cited therein, to which full refer- ence is made. The polyestercarbonates contained in resin composition of the present invention can be prepared by reacting a diol component comprising a monomer of formula (VI) and optionally a further diol monomer such as a monomer of the formula (IV), a carbonate M / REUCTR-054-PC 63 forming monomer and a dicarboxylic acid or its ester forming derivative by analogy to the well known preparation of polyestercarbonates as described in the art. The polycarbonates, polyesters and polyestercarbonates are usually prepared by react- ing the monomers of the diol component with the carbonate forming monomers and / or the ester forming monomers, i.e. the dicarboxylic acids or the ester forming derivatives thereof, in the presence of an esterification catalyst, in particular a transesterification catalyst, in case a carbonate forming monomer or an ester forming derivative of a pol- ycarboxylic acid is used. Suitable transesterification catalysts are basic compounds, which specifically include but are not limited to alkaline metal compounds, alkaline earth metal compound, nitro- gen-containing compounds, and the like. Likewise, suitable transesterification catalysts are acidic compounds, which specifically include but are not limited to Lewis acid com- pounds of polyvalent metals, including compounds such as zinc, tin, titanium, zirco- nium, lead, and the like. Examples of suitable alkaline metal compound include alkaline metal salts of an organic acid such as acetic acid, stearic acid, benzoic acid, or phenylphorsphoric acid, alkaline metal phenolates, alkaline metal oxides, alkaline metal carbonates, alkaline metal boro- hydrides, alkaline metal hydrogen carbonates, alkaline metal phosphate, alkaline metal hydrogenphosphate, alkaline metal hydroxides, alkaline metal hydrides, alkaline metal alkoxides, and the like. Specific examples thereof include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stea- rate, cesium stearate, lithium stearate, sodium borohydride, sodium borophenoxide, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, and disodium phenylphosphate; and also include disodium salt, dipotassium salt, dice- sium salt, dilithium salt of bisphenol A, sodium salt, potassium salt, cesium salt and lithium salt of phenol; and the like. Examples of the alkaline earth metal compound include alkaline earth metal salts of an organic acid such as acetic acid, stearic acid, benzoic acid, or phenylphorsphoric acid, alkaline earth metal phenolates, alkaline earth metal earth oxides, alkaline earth metal carbonates, alkaline metal borohydrides, alkaline earth metal hydrogen carbonates, al- kaline earth metal hydroxides, alkaline earth metal hydrides, alkaline earth metal alkoxides, and the like. Specific examples thereof include magnesium hydroxide, cal- cium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen car- bonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen M / REUCTR-054-PC 64 carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium car- bonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, mag- nesium stearate, calcium stearate, calcium benzoate, magnesium phenylphosphate, and the like. Examples of the nitrogen-containing compound include quaternary ammoniumhydrox- ide, salt thereof, amines, and the like. Specific examples thereof include quaternary ammoniumhydroxides including an alkyl group, an aryl group or the like, such as tetra- methylammoniumhydroxide, tetraethylammoniumhydroxide, tetrapropylammoniumhy- droxide, tetrabutylammoniumhydroxide, trimethylbenzylammoniumhydroxide, and the like; tertiary amines such as triphenylamine, dimethylbenzylamine, triphenylamine, and the like; secondary amines such as diethylamine, dibutylamine, and the like; primary amines such as propylamine, butylamine, and the like; imidazoles such as 2-methylim- idazole, 2-phenylimidazole, benzoimidazole, and the like; bases or basic salts such as ammonia, tetramethylammoniumborohydride, tetrabutylammoniumborohydride, tet- rabutylammoniumtetraphenylborate, tetraphenylammoniumtetraphenylborate, and the like. Preferred examples of the transesterification catalyst include salts of polyvalent metals such as zinc, tin, titanium, zirconium, lead, and the like, in particular the chlorides, alkoxyides, alkanoates, benzoates, acetylacetonates and the like. They may be used in- dependently or in a combination of two or more. Specific examples of such transesteri- fication catalyst include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin chloride (II), tin chloride (IV), tin acetate (II), tin acetate (IV), dibutyltinlaurate, dibutyltinoxide, dibutyltinmethoxide, zirconiumacetylacetonate, zirconium oxyacetate, zirconiumtet- rabutoxide, lead acetate (II), lead acetate (IV), and the like. The transesterification catalyst are frequently used at a ratio of 10-9to 10-3mol, prefer- ably 10-7to 10-4mol, with respect to 1 mol of the dihydroxy compound(s) in total. Frequently, the polycarbonates, polyesters and polyestercarbonates are prepared by a melt polycondensation method. In the melt polycondensation the monomers are re- acted in the absence of an additional inert solvent. While the reaction is performed any byproduct formed in the transesterification reaction is removed by heating the reaction mixture at ambient pressure or reduced pressure. The melt polycondensation reaction preferably comprises charging the monomers and catalyst into a reactor and subjecting the reaction mixture to conditions, where the re- action between the monomers and the formation of the byproduct takes place. It has been found advantageous, if the byproduct resides for at least a while in the polycon- densation reaction. However, in order to drive the polycondensation reaction to the M / REUCTR-054-PC 65 product side, it is beneficial to remove at least a portion of the formed byproduct dur- ing or preferably at the end of the polycondensation reaction. In order to allow the by- product in the reaction mixture, the pressure may be controlled by closing the reactor, or by increasing or decreasing the pressure. The reaction time for this step is 20 minutes or longer and 240 minutes or shorter, preferably 40 minutes or longer and 180 minutes or shorter, and especially preferably 60 minutes or longer and 150 minutes or shorter. In this step, in the case where the byproduct is removed by distillation soon after being generated, the finally obtained thermoplastic resin has a low content of high molecular-weight resin molecules. By contrast, in the case where the byproduct is allowed to reside in the reactor for a certain time, the finally obtained thermoplastic resin has a high content of high molecular-weight resin molecules. The melt polycondensation reaction may be performed in a continuous system or in a batch system. The reactor usable for the reaction may be of a vertical type including an anchor-type stirring blade, a Maxblend®stirring blade, a helical ribbon-type stirring blade or the like; of a horizontal type including a paddle blade, a lattice blade, an eye glass-type blade or the like; or an extruder type including a screw. A reactor including a combination of such reactors is preferably usable in consideration of the viscosity of the polymerization product. According to the method for producing the thermoplastic resin, such as a polycar- bonate resin, after the polymerization reaction is finished, the catalyst may be removed or deactivated in order to maintain the thermal stability and the hydrolysis stability. A preferred method for deactivating the catalyst is the addition of an acidic substance. Specific examples of the acidic substance include esters such as butyl benzoate and the like; aromatic sulfonates such as p-toluenesulfonic acid and the like; aromatic sul- fonic acid esters such as butyl p-toluenesulfonate, hexyl p-toluenesulfonate, and the like; phosphoric acids such as phosphorous acid, phosphoric acid, phosphonic acid, and the like; phosphorous acid esters such as triphenyl phosphite, monophenyl phosphite, diphenyl phosphite, diethyl phosphite, di-n-propyl phosphite, di-n-butyl phosphite, di-n- hexyl phosphite, dioctyl phosphite, monooctyl phosphite, and the like; phosphoric acid esters such as triphenyl phosphate, diphenyl phosphate, monophenyl phosphate, dibu- tyl phosphate, dioctyl phosphate, monooctyl phosphate, and the like; phosphonic acids such as diphenyl phosphonic acid, dioctyl phosphonic acid, dibutyl phosphonic acid, and the like; phosphonic acid esters such as diethyl phenylphosphonate, and the like; phosphines such as triphenylphosphine, bis(diphenylphosphino)ethane, and the like; boric acids such as boric acid, phenylboric acid, and the like; aromatic sulfonic acid salts such as tetarabutylphosphonium dodecylbenzensulfonate salt, and the like; or- ganic halides such as chloride stearate, benzoyl chloride, chloride p-toluenesulfonate, and the like; alkylsulfonic acids such as dimethylsulfonic acid, and the like; organic hal- ides such as benzyl chloride, and the like. These deactivators are frequently used at 0.01 to 50 mol, preferably 0.3 to 20 mol, with respect to the catalyst. After the catalyst M / REUCTR-054-PC 66 has been deactivated, there may be a step of removing low boiling point compounds from the polymer by distillation. The distillation is preferably performed at reduced pressure, e.g. at a pressure of 0.1 to 1 mm Hg at a temperature of 200 to 350°C. For this step, a horizontal device including a stirring blade having a high surface renewal capability such as a paddle blade, a lattice blade, an eye glass-type blade or the like, or a thin film evaporator is preferably used. It is desirable that the thermoplastic resin such as a polycarbonate resin has a very small amount of foreign objects. Therefore, the molten product is preferably filtered to remove any solids from the melt. The mesh of the filter is preferably 5 µm or less, and more preferably 1 µm or less. It is preferred that the generated polymer is filtrated by a polymer filter. The mesh of the polymer filter is preferably 100 µm or less, and more preferably 30 µm or less. A step of sampling a resin pellet needs to be performed in a low dust environment, needless to say. The dust environment is preferably of class 6 or lower, and more preferably of class 5 or lower. The resin composition may be molded by any conventional molding procedure for pro- ducing optical elements. Suitable molding procedures include but are not limited to in- jection molding, compression molding, casting, roll processing, extrusion molding, ex- tension and the like. While it is possible to mold the resin composition of the invention as such, it is also possible to mold a resin composition, which contains at least one thermoplastic resin as described herein and which further contains at least one additive and / or further resin. Suitable additives include antioxidants, processing stabilizers, photostabilizers, polymerization metal deactivators, flame retardants, lubricants, antistatic agents, sur- factants, antibacterial agents, releasing agents, ultraviolet absorbers, plasticizers, com- patibilizers, and the like. Suitable further resins are e.g. another polycarbonate resin, polyester carbonate resin, polyester resin, polyamide, polyacetal and the like, which does not contain repeating units of the formula (VI-1), (VI-2) or (VI-3). Examples of the antioxidant include but are not limited to triethyleneglycol-bis[3-(3- tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-bu- tyl-4-hydroxyphenyl)propionate], pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydrox- yphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphospha- spiro[5.5]undecane, 5,7-Di-tert-butyl-3-(3,4-dimethylphenyl)benzofuran-2(3H)-one, 5,7-Di-tert-butyl-3-(1,2dimethylphenyl)benzofuran-2(3H)-one, 1,3,5-trimethyl-2,4,6- tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, N,N-hexamethylenebis(3,5-di-tert-bu- tyl-4-hydroxy-hydrocinnamide, 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethy- lester, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, and 3,9-bis{1,1-dimethyl-2- [β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl}-2,4,8,10- M / REUCTR-054-PC 67 tetraoxaspiro(5,5)undecane, and the like. Among these examples, 3,9-bis(2,6-di-tert- butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 5,7-Di- tert-butyl-3-(3,4-dimethylphenyl)benzofuran-2(3H)-one, and 5,7-Di-tert-butyl-3-(1,2di- methylphenyl)benzofuran-2(3H)-one are more preferred. The content of the antioxi- dant in the thermoplastic resin is preferably 0.001 to 0.3 parts by weight with respect to 100 parts by weight of the thermoplastic resin. Examples of the processing stabilizer include but are not limited to phosphorus-based processing stabilizers, sulfur-based processing stabilizers, and the like. Examples of the phosphorus-based processing stabilizer include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, esters thereof, and the like. Specific examples thereof include triphenylphosphite, tris(nonylphenyl)phosphite, tris(2,4-di-tert-bu- tylphenyl)phosphite, tris(2,6-di-tert-butylphenyl)phosphite, tridecylphosphite, trioctylphosphite, trioctadecylphosphite, didecylmonophenylphosphite, dioctylmonophe- nylphosphite, diisopropylmonophenylphosphite, monobutyldiphenylphosphite, monodecyldiphenylphosphite, monooctyldiphenylphosphite, bis(2,6-di-tert-butyl-4- methylphenyl)pentaerythritoldiphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)oc- tylphosphite, bis(nonylphenyl)pentaerythritoldiphosphite, bis(2,4-dicumylphenyl)pen- taerythritoldiphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritoldiphosphite, dis- tearylpentaerythritoldiphosphite, tributylphosphate, triethylphosphate, trime- thylphosphate, triphenylphosphate, diphenylmonoorthoxenylphosphate, dibu- tylphosphate, dioctylphosphate, diisopropylphosphate, dimethyl benzenephosphonate, diethyl benzenephosphonate, dipropyl benzenephosphonate, tetrakis(2,4-di-t-bu- tylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-t-butylphenyl)-4,3'-bi- phenylenediphosphonite, tetrakis(2,4-di-t-butylphenyl)-3,3'-biphenylenediphosphonite, bis(2,4-di-tert-butylphenyl)-4-phenyl-phenylphosphonite, bis(2,4-di-tert-butylphenyl)-3- phenyl-phenylphosphonite, and the like. The content of the phosphorus-based pro- cessing stabilizer in the thermoplastic resin composition is preferably 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the thermoplastic resin. Examples of the sulfur-based processing stabilizer include but are not limited to pen- taerythritol-tetrakis(3-laurylthiopropionate), pentaerythritol-tetrakis(3-myristylthiopropi- onate), pentaerythritol-tetrakis(3-stearylthiopropionate), dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, and the like. The con- tent of the sulfur-based processing stabilizer in the thermoplastic resin compositon is preferably 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the ther- moplastic resin. Preferred releasing agents contain at least 90% by weight of an ester of an alcohol and a fatty acid. Specific examples of the ester of an alcohol and a fatty acid include an ester of a monovalent alcohol and a fatty acid, and a partial ester or a total ester of a polyvalent alcohol and a fatty acid. Preferred examples of the above-described ester M / REUCTR-054-PC 68 of an alcohol and a fatty acid include the esters of a monovalent alcohol having a car- bon number of 1 to 20 and a saturated fatty acid having a carbon number of 10 to 30. Preferred examples of partial or total esters of a polyvalent alcohol and a fatty acid in- clude the partial or total ester of a polyvalent alcohol having a carbon number of 2 to 25 and a saturated fatty acid having a carbon number of 10 to 30. Specific examples of the ester of a monovalent alcohol and a fatty acid include stearyl stearate, palmityl pal- mitate, butyl stearate, methyl laurate, isopropyl palmitate, and the like. Specific exam- ples of the partial or total ester of a polyvalent alcohol and a fatty acid include mono- glyceride stearate, monoglyceride stearate, diglyceride stearate, triglyceride stearate, monosorbitate stearate, monoglyceride behenate, monoglyceride caprylate, mono- glyceride laurate, pentaerythritol monostearate, pentaerythritol tetrastearate, pentae- rythritol tetrapelargonate, propyleneglycol monostearate, biphenyl biphenate, sorbitan monostearate, 2-ethylhexylstearate, total or partial esters of dipentaerythritol such as dipentaerythritol hexastearate and the like, etc. The content of the releasing agent in the resin composition is preferably 0.005 to 2.0 parts by weight, more preferably 0.01 to 0.6 parts by weight, and still more preferably 0.02 to 0.5 parts by weight, with re- spect to 100 parts by weight of the thermoplastic resin. Preferred ultraviolet absorbers are selected from the group consisting of benzotriazole- based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, cyclic iminoester-based ultraviolet absorbers, and cyanoacrylate- based ultraviolet absorbers. Namely, the following ultraviolet absorbers may be used independently or in a combination of two or more. Examples of benzotriazole-based ultraviolet absorbers include 2-(2-hydroxy-5- methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hy- droxy-3,5-dicumylphenyl)phenylbenzotriazole, 2-(2-hydroxy-3-tert-butyl-5- methylphenyl)-5-chlorobenzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6- (2N-benzotriazole-2-yl)phenol)], 2-(2-hydroxy-3,5-di-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert- amylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy- 5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy-4-octoxyphenyl)benzotriazole, 2,2'- methylenebis(4-cumyl-6-benzotriazolephenyl), 2,2'-p-phenylenebis(1,3-benzoxazine-4- one), 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidemethyl)-5-methylphenyl]benzotria- zole, and the like. Examples of benzophenone-based ultraviolet absorbers include 2,4-dihydroxybenzo- phenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid hydrate, 2,2'-dihydroxy-4-methoxy- benzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethox- ybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5-sodiumsulfoxybenzophenone, bis(5- M / REUCTR-054-PC 69 benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2-hydroxy-4-n-dodecyloxybenzophe- none, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, and the like. Examples of triazine-based ultraviolet absorbers include 2-(4,6-diphenyl-1,3,5-triazine- 2-yl)-5-([(hexyl)oxy]-phenol, 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5- ([(octyl)oxy]-phenol, and the like. Examples of cyclic iminoester-based ultraviolet absorbers include 2,2'-bis(3,1-benzoxa- zine-4-one), 2,2'-p-phenylenebis(3,1-benzoxazine-4-one), 2,2'-m-phenylenebis(3,1- benzoxazine-4-one), 2,2'-(4,4'diphenylene)bis(3,1-benzoxazine-4-one), 2,2'-(2,6-naph- thalene)bis(3,1-benzoxazine-4-one), 2,2'-(1,5-naphthalene)bis(3,1-benzoxazine-4-one), 2,2'-(2-methyl-p-phenylene)bis(3,1-benzoxazine-4-one), 2,2'-(2-nitro-p-phe- nylene)bis(3,1-benzoxazine-4-one), 2,2'-(2-chloro-p-phenylene)bis(3,1-benzoxazine-4- one), and the like. Examples of cyanoacrylate-based ultraviolet absorbers include 1,3-bis-[(2'-cyano-3',3'- diphenylacryloyl)oxy]-2,2-bis(((2-cyano-3,3-diphenylacryloyl)oxy)methyl)propane, 1,3-bis-[(2-cyano-3,3-diphenylacryloyl)oxy]benzene, and the like. The content of the ultraviolet absorber in the resin composition is preferably 0.01 to 3.0 parts by weight, more preferably 0.02 to 1.0 parts by weight, and still more prefer- ably 0.05 to 0.8 parts by weight, with respect to 100 parts by weight of the thermo- plastic resin. The ultraviolet absorber contained in such a range of content in accord- ance with the use may provide a sufficient climate resistance to the thermoplastic resin. As mentioned above, the thermoplastic polymer resins contained in the resin composi- tions of the present invention, in particular the polycarbonate resins comprising repeat- ing units of formulae (II-1), (II-2) and (II-3), respectively, as described herein, provide high transparency and high refractive index to thermoplastic resins. The resin composi- tions of the present invention containing these thermoplastic polymer resins are there- fore suitable for preparing optical devices, where high transparency and high refractive index is required. More precisely, the resin compositions of the present invention con- taining these thermoplastic polycarbonates having structural units of formulae (II-1), (II-2) and (II-3), respectively, are characterized by having a high refractive index, which is preferably at least 1.660, more preferably at least 1.680, in particular at least 1.690. The contribution of the monomer of the formulae (VI-1), (VI-1 and (VI-3), respectively, to the refractive index of the thermoplastic resin, in particular a polycarbonate resin, contained in the resin composition of the invention will depend from the refractive in- dex of said monomer and the relative amount of said monomer in the thermoplastic M / REUCTR-054-PC 70 resin. In general, a higher refractive index of the monomer contained in the thermo- plastic resin will result in a higher refractive index of the resulting thermoplastic resin. Apart from that, the refractive index of a thermoplastic resin comprising structural units of the formula (II) can be calculated from the refractive indices of the monomers used for preparing the thermoplastic resin, either from the refractive index of the mon- omers or ab initio, e.g. by using the computer software ACD / ChemSketch 2012 (Ad- vanced Chemistry Development, Inc.). In case of thermoplastic copolymer resins, the refractive index of the thermoplastic resin, in particular a polycarbonate resin, can be calculated from the refractive indices of the homopolymers of the respective monomers, which form the copolymer resin, by the following so called “Fox equation”: 1 / nD= x1 / nD1+ x2 / nD2+ .... xn / nDn, where nD is the refractive index of the copolymer, x1, x2, .... xn are the mass fractions of the monomers 1, 2, .... n in the copolymer and nD1, nD2, .... nDnare the refractive in- dices of the homopolymers synthesized from only one of the monomers 1, 2, .... n at a time. In case of polycarbonates, x1, x2, .... xn are the mass fractions of the OH mono- mers 1, 2, .... n, based on the total amount of OH monomer. It is apparent that a higher refractive index of a homopolymer will result in a higher refractive index of the copolymer. The refractive indices of the resin composition of the present invention and of thermo- plastic resins contained therein can be determined directly, whereas the refractive indi- ces of the thermoplastic resins can also be determinted indirectly. For direct determi- nation, the refractive indices nDof the resin compositions or the thermoplastic resins are measured at wavelength of 589 nm in accordance with the protocol JIS-K-7142 us- ing an Abbe refractometer and applying a 0.1 mm film of the composition or the resin. In case of the refractive indices of the homopolycarbonates of the compounds of for- mula (VI), the refractive indices can also be determined indirectly. For this, a co-poly- carbonate of the respective monomer of formula (VI) with 9,9-bis(4-(2-hydroxyeth- oxy)phenyl)fluorene and diphenyl carbonate is prepared according to the protocol of example 1 in column 48 of US 9,360,593 and the refractive indices nD of the co-poly- carbonate is measured at wavelength of 589 nm in accordance with the protocol JIS-K- 7142 using an Abbe refractometer and applying a 0.1 mm film of the co-polycarbonate. From the thus measured refractive indices nD, the refractive index of the homopolycar- bonate of the respective monomer can be calculated by applying the Fox equation and the known refractive index of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (nD(589 nm) = 1.639). M / REUCTR-054-PC 71 The compounds of formula (VI) can be obtained in a purity, which provides for a low yellowness index Y.I., as determined in accordance with ASTM E313, which may also be important for the use in the preparation of optical resins. More precisely, the yellowness index Y.I., as determined in accordance with ASTM E313, of the compounds of formula (VI) preferably does not exceed 100, more prefer- ably 50, even more preferably 20, in particular 10 or 5. The resin composition according to the present invention has a high refractive index and a low Abbe number. The resin composition of the present invention can be used for producing a transparent conductive substrate usable for a liquid crystal display, an organic EL display, a solar cell and the like. Also, the resin composition of the present invention can be used as a structural material for optical parts, such as, optical disks, liquid crystal panels, optical cards, optical sheets, optical fibers, connectors, evaporated plastic reflecting mirrors, displays, and the like; or used as optical devices suitable for functional material purpose. Accordingly, molded articles, such as optical devices can be formed using the resin compositions of the present invention. The optical devices include optical lenses, and optical films. The specific examples of the optical devices include lenses, films, mirrors, filters, prisms, and so on. These optical devices can be formed by arbitrary production process, for example, by injection molding, compression molding, injection compres- sion molding, extrusion molding, or solution casting. Because of an excellent moldability and a high heat resistance, the resin compositions of the present invention are very suitable for production of optical lenses which re- quires injection molding. For molding, the resin compositions of the present invention, such as those including a polycarbonate resin with structural units of formula (II) and a compound of formula (I) as an additive, may further include other thermoplastic res- ins, for example, different polycarbonate resin, polyestercarbonate resin, polyester resin, and other resins, in mixed form. In addition, the resin compositions of the present invention can be mixed with addi- tives for forming the optical devices, which are different from the compounds of for- mula (I), (Ia) or (Ib). As such additives for forming the optical devices, the above- mentioned ones can be used. These additives may include antioxidants, processing stabilizers, photostabilizers, polymerization metal deactivators, flame retardants, lubri- cants, antistatic agents, surfactants, antibacterial agents, releasing agents, ultraviolet absorbers, plasticizers, compatibilizers, and the like. As is clear from the above, another aspect of the present invention relates to an optical device made of a resin composition as defined above, where the resin composiiton M / REUCTR-054-PC 72 comprises a compound of formulae (I), (Ia) or (Ib) and a thermoplastic resin prefera- bly comprising a structural unit represented by the formula (II) and optionally of for- mula (V). As regards to the preferred meanings and preferred embodiments of the structural units of the formulae (II) and (V), reference is made to the statements given above. An optical device made of an optical resin composition as defined herein are usually optical molded articles such as optical lenses, for example car head lamp lenses, Fres- nel lenses, fθ lenses for laser printers, camera lenses, lenses for glasses and projection lenses for rear projection TV's, CD-ROM pick-up lenses, but also optical disks, optical elements for image display media, optical films, film substrates, optical filters or prisms, liquid crystal panels, optical cards, optical sheets, optical fibers, optical con- nectors, eposition plastic reflective mirrors, and the like. Here particular preference is given to optical lenses and optical films. Optical resin compositions comprising com- pounds of formulae (I), (Ia) or (Ib) and a thermoplastic resin preferably having a structural unit represented by the formula (II) and optionally of formula (V) are also useful for producing a transparent conductive substrate usable for an optical device suitable as a structural member or a functional member of a transparent conductive substrate for a liquid crystal display, an organic EL display, a solar cell and the like. The optical lens produced from the resin composition according to the present inven- tion has a high refractive index, a low Abbe number and a low degree of birefringence, and is highly moisture and heat resistant. Therefore, the optical lens can be used in the field in which a costly glass lens having a high refractive index is conventionally used, such as for a telescope, binoculars, a TV projector and the like. It is preferred that the optical lens is used in the form of an aspherical lens. Merely one aspherical lens may make the spherical aberration substantially zero. Therefore, it is not neces- sary to use a plurality of spherical lenses to remove the spherical aberration. Thereby the weight and the production cost of a device including the spherical aberration is de- creased. An aspherical lens is useful especially as a camera lens among various types of optical lenses. The present invention easily provides an aspherical lens having a high refractive index and a low level of birefringence, which is technologically difficult to produce by processing glass. An optical lens of the present invention may be formed, for example, by injection molding, compression molding, injection compression molding or casting the resin composition comprising a compound of formula (I) and a thermoplasting resin prefera- bly having repeating units of the formula (II) and optionally repeating units of the for- mula (V) as defined herein. The optical lens of the present invention is characterized by a small optical distortion. An optical lens comprising a conventional optical resin has a large optical distortion. M / REUCTR-054-PC 73 Although it is not impossible to reduce the value of an optical distortion by molding conditions, the condition widths are very small, thereby making molding extremely dif- ficult. Since the resin composition including a compound (I) and a thermoplastic resin with repeating units of the formula (II) and optionally repeating units of the formula (V) as defined herein has an extremely small optical distortion caused by the orienta- tion of the resin and a small molding distortion, an excellent optical element can be ob- tained without setting molding conditions strictly. To manufacture the optical lens of the present invention by injection molding, it is pre- ferred that the lens should be molded at a cylinder temperature of 260°C to 320°C and a mold temperature of 100°C to 140°C. The optical lens of the present invention is advantageously used as an aspherical lens as required. Since spherical aberration can be substantially nullified with a single as- pherical lens, spherical aberration does not need to be removed with a combination of spherical lenses, thereby making it possible to reduce the weight and the production cost. Therefore, out of optical lenses, the aspherical lens is particularly useful as a camera lens. Since resin compositions including a compound (I) and a thermoplastic resin preferably having repeating units of the formula (II) and optionally repeating units of the formula (V) as defined herein have a high moldability, they are particularly useful as the mate- rial of an optical lens, which is thin and small in size and has a complex shape. As a lens size, the thickness of the center part of the lens is 0.05 to 3.0 mm, preferably 0.05 to 2.0 mm, more preferably 0.1 to 2.0 mm. The diameter of the lens is 1.0 to 20.0 mm, preferably 1.0 to 10.0 mm, more preferably 3.0 to 10.0 mm. It is preferably a meniscus lens, which is convex on one side and concave on the other side. The surface of the optical lens of the present invention may have a coating layer such as an antireflection layer or a hard coat layer as required. The antireflection layer may be a single layer or a multi-layer and composed of an organic material or inorganic ma- terial but preferably an inorganic material. Examples of the inorganic material include oxides and fluorides such as silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, magnesium oxide and magnesium fluoride. The optical lens of the present invention may be formed by an arbitrary method such as metal molding, cutting, polishing, laser machining, discharge machining or edging. Metal molding is preferred. An optical film produced by the use of the thermoplastic resin composition according to the present invention is high in transparency and heat resistance, and therefore is preferably usable for a liquid crystal substrate film, an optical memory card or the like. M / REUCTR-054-PC 74 In order to avoid foreign objects from being incorporated into the optical film as much as possible, the molding needs to be performed in a low dust environment, needless to say. The dust environment is preferably of class 6 or lower, and more preferably of class 5 or lower. The following examples serve as further illustration of the invention. 1. Abbreviations: m.p.: melting point wt%: percent by weight eq.: molar equivalent(s) r.t.: room temperature h: hour MEK: methylethylketone (butan-2-one) CuI: copper(I) iodide DMF: dimethylformamide Fe(acac)3: iron(III) acetylacetonate HCl: hydrochloric acid K2CO3: potassium carbonate NaOH: sodium hydroxide NaHCO3: sodium hydrogen carbonate Na2SO4: sodium sulfate THF: tetrahydrofuran TEA: triethylamine TLC: thin layer chromatography nD: Refractive index ^^ Abbe number Mw: Molecular weight Tg: Glass transition temperature GPC: Gel permeation chromatography DPBN: 2,2'-((6,6'-diphenyl-[1,1'-binaphthalene]-2,2'-diyl)bis(oxy))bis(ethan-1-ol) BNEF: 9,9-bis[6-(2-hydroxyethoxy)naphthalene-2-yl]fluorene BNE: 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl DPC: diphenylcarbonate 2. Preparation of additive compounds of formula (I) 2.1 Analytics relating to the compounds of formula (I):1H-NMR spectra were determined at 23°C using an 80 MHz NMR-spectrometer (Ma- gritek Spinsolve 80). If not stated otherwise the solvent was CDCl3. M / REUCTR-054-PC 75 Melting points of the compounds were determined by Büchi Melting Point B-545. 2.2 Preparation Examples: Example 1: 2,2'-bis(benzyloxy)-1,1’-binaphthalene (DBNBNA; compound of formula (Ia), with k and l = 0, Ar1and Ar2= phenyl, L1and L2= CH2 and p and q = 0; com- pound 9 of table A) To racemic 1,1'-binaphthalene-2,2'-diol (also called 1,1’-bi-2-naphthol; 250 g; 873.1 mmol) dissolved in MEK (1.5 kg) K2CO3 (555.1 g) was added. The mixture was stirred at 60 °C for 1 h. Then bromomethyl-benzene (328.5 g; approx. 228.15 mL; 1.92 mol; 2.2 eq.) was added and the mixture was stirred at reflux until the TLC (elu- ent: cyclohexane / ethyl acetate = 10 / 1) showed complete conversion. The mixture was cooled to r.t. and water (ca. 1.0 L) was added. After phase separation the organic layer was washed with water (500 g) and then with a 10%-solution of citric acid (500 g), and finally with brine (500 g). The solvent was removed under reduced pres- sure and the crude product was recrystallized from cyclohexane (ca. 1.5 L) to obtain 338.3 g of desired product with chemical purity of 98.4 %. After further recrystalliza- tion using the same procedure 2,2'-bis(benzyloxy)-1,1'-binaphthalene [DBNBNA] was obtained with chemical purity of > 99.5%.1H NMR (80 MHz, CDCl3): δ = 8.05 – 7.60 (m, 4H), 7.53 – 6.71 (m, 14H), 4.99 (s, 4H) ppm. Example 2: Synthesis of 2-benzyloxy-2’-[(2’-benzyloxy-1,1’-binaphthyl-2-oxy)-1- ethyloxy]-1,1'-binaphthalene (DBBNAE; compound of formula (Ib), with l = 1, k = 0, Ar1= 1-(2-benzyloxy-1-naphthyl)naphthalene-2-yl, Ar2= phenyl, L1= single bond, L2= CH2 and p and q = 0; compound 5 of table A) Example 2a: Synthesis of 2'-(benzyloxy)-1,1'-binaphthalen-2-ol (building block 1; BnBNA) M / REUCTR-054-PC 76 To a mixture of racemic 1,1’-bi-2-naphthol (250 g, 873 mmol, 1.0 eq.) and K2CO3(350 g, 2.53 mol, 2.9 eq.) in acetone (1.5 kg) benzyl bromide (109 ml, 917 mmol, 1.05 eq.) was added dropwise. The mixture was then heated to reflux until TLC showed no fur- ther conversion (approx. 2 h). The reaction mixture was cooled to r.t., then water (300 g) was added and the acetone was removed under vacuum. Toluene (170 g) and n-heptane (500 g) were added to the residue and the mixture was stirred vigorously for several hours. The crystalline solid was filtered off and washed with pentane. The solid was then heated together with toluene (330 g) and a 6 M aqueous solution of HCl (330g) at 80 °C until two homogenous phases formed. The phases were separated and the organic phase was concentrated under reduced pressure. Methanol (600 g) was added to the residue and the mixture stirred at r.t.. The formed crystals were filtered off to give the title compound as a white solid (177 g, 471 mmol, yield: 54%, chemical purity: >99%).1H NMR (80 MHz, CDCl3): δ = 8.13-7.79 (m, 4H), 7.64-6.97 (m, 13H), 5.24 (s, 1H, OH), 5.10 (s, 2H) ppm. Example 2b: Synthesis of ethane-1,2-diyl bis(4-methylbenzene-1-sulfonate) (building block 2; EGDT) A solution of ethylene glycol (50.0 g, 806 mmol, 1.0 eq.) in THF (450 g) was added a solution of NaOH (74.1 g, 1.85 mol, 2.3 eq.) in water (100 g) and stirred at r.t. for 2 h. The mixture was then cooled to 0 °C and tosyl chloride (307 g, 1.61 mol, 2.0 eq.) was added portionwise over 2 h. Stirring was continued at 0 °C for 2 h. Then the reaction was warmed to r.t. overnight. The mixture was poured into a 2 M aqueous solution of HCl (1.5 kg) and the formed solid was filtered off, washed with water and then with methanol to give the product as a white solid (220 g, 594 mmol, yield: 74%, chemical purity >99%).1H NMR (80 MHz, CDCl3): δ = 7.87-7.62 (m, 4H), 7.48-7.20 (m, 4H), 4.20 (s, 4H), 2.47 (s, 6H) ppm. M / REUCTR-054-PC 77 Example 2c: Synthesis of 2-benzyloxy-2’-[(2’-benzyloxy-1,1’-binaphthyl-2-oxy)-1- ethyloxy]-1,1'-binaphthalene (DBBNAE; compound of formula (Ib), with l = 1, k = 0, Ar1= 1-(2-benzyloxy-1-naphthyl)naphthalene-2-yl, Ar2= phenyl, L1= single bond, L2= CH2 and p and q = 0; compound 5 of table A) To a mixture of BnBNA (see Example 2a; 279 g, 742 mmol, 2.2 eq.) and K2CO3 (233 g, 1.69 mol, 5.0 eq.) in DMF (1000 mL) EGDT (see Example 2b; 125 g, 337 mmol, 1.0 eq.) was added portionwise. The mixture was then heated to reflux until TLC showed complete conversion. The reaction was cooled to r.t. and water (2000 mL) was added. The solvent was decanted off and water (1000 mL) was added to the residue. The suspension was stirred vigorously and the crude product was filtered off. Repeated recrystallization from ethanol gave the desired product as a white solid (122 g, 157 mmol, yield: 46%, chemical purity: 97.4%).1H NMR (80 MHz, CDCl3): δ = 8.06-7.53 (m, 8H), 7.51-6.60 (m, 26H), 4.90 (s, 4H, dia- stereomer 1), 4.84 (s, 4H, diastereomer 2), 3.86 (s, 4H) ppm. Example 3: Synthesis of 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1-ethyloxy]- 1,1'-binaphthalene (DBBNABHBNA; compound of formula (Ib), with l and k = 1, Ar1and Ar2= 1-(2-benzyloxy-1-naphthyl)naphthalene-2-yl, L1and L2= single bond, and p and q = 0; compound 1 of table A) Example 3a: Synthesis of [([1,1'-binaphthalene]-2,2'-diyl)bis(oxy)ethane-2,1-diyl] di- methanesulfonate (building block 3; BHBNADMs) 2,2'-Bis(2-hydroxyethoxy)-1,1'-binaphthyl (BHBNA; 300 g, 801 mmol, 1.0 eq.) and TEA (335 mL, 2.40 mol, 3.0 eq.) were added to dichloromethane (2000 mL) and the mix- ture was cooled to 0°C. Methanesulfonyl chloride (186 mL, 2.40 mol, 3.0 eq.) was then added dropwise. Stirring was continued at 0°C for an additional 2 h and the reaction mixture was then allowed to warm to r.t.. The reaction mixture was stirred until TLC showed complete conversion. Water was added and the phases were separated. The organic phase was washed with a saturated aqueous solution of NaHCO3, dried over Na2SO4 and the solvent was removed in vacuo to give the crude product. The material M / REUCTR-054-PC 78 was stirred in acetone (500 g) at reflux for 1 h, followed by cooling to r.t. and filtration to give the desired product as a white solid (357 g, 673 mmol, yield: 84%).1H NMR (80 MHz, CDCl3): δ = 8.11-7.74 (m, 4H), 7.53-6.97 (m, 8H), 4.24 (mc, 8H), 2.12 (s, 6H) ppm. Example 3b: Synthesis of 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1-ethyloxy]- 1,1'-binaphthalene (DBBNABHBNA; compound of formula (Ib), with l and k = 1, Ar1and Ar2= 1-(2-benzyloxy-1-naphthyl)naphthalene-2-yl, L1and L2= single bond, and p and q = 0; compound 1 of table A) To a mixture of BnBNA (see Example 2a; 50.0 g, 133 mmol, 2.07 eq.) and K2CO3 (51.4 g, 372 mmol, 5.8 eq.) in DMF (500 g) BHBNADMs (see Example 3a; 34.0 g, 64.1 mmol, 1.0 eq.) was added portionwise. The mixture was then heated to reflux un- til TLC showed complete conversion. The reaction was cooled to r.t. and water (1000 mL) was added. The crude product was filtered off. Purification by column chro- matography (solvent: cyclohexane / ethyl acetate, gradient 10:1 to 1:1) gave the de- sired product as a white solid (20.0 g, 18.3 mmol, yield: 35%, chemical purity: 97.5%).1H NMR (80 MHz, CDCl3): δ = 8.07-6.72 (m, 46H), 4.89 (s, 4H), 4.07-3.64 (m, 8H) ppm. Example 4: 2,2'-bis(4-cyano-phenoxy)-1,1’-binaphthalene (BNAD4PODCN; compound of formula (Ia), with k and l = 0, Ar1and Ar2= 4-cyanophenyl, L1and L2= single bond and p and q = 0; compound 20 of table A) To 1,1’-bi-2-naphthol (101.23 g; 350 mmol) dissolved in N,N-dimethylformamide (350 g) K2CO3(120.93 g) was added. The mixture was stirred at 60 °C for 1 h. Then 4- fluorobenzonitrile (105.97 g; 875 mmol; 2.5 eq.) was added and the mixture was stirred at reflux until the TLC (eluent: cyclohexane / ethyl acetate = 3 / 1) showed a complete conversion (approximately 2 h). The mixture was cooled to 70 °C and water (ca. 2.8 L) was added. The suspension was stirred at 1 h at r.t. and the precipitated M / REUCTR-054-PC 79 solid was filtered off, washed with water (3×250 mL) and then washed with isopropa- nol (250 mL) and dried in vacuo to obtain approx. 170 g of crude product. The crude product was dissolved in tetrahydrofuran (1.87 kg) and to the obtained solu- tion activated charcoal (Norit DX 1) was added. The mixture was stirred for 2 h at 50 °C, cooled to r.t. and the mixture was then filtered over celite and the solution was concentrated under reduced pressure. Afterwards toluene (600 g) was added and the mixture stirred overnight. The precipitated crystals were collected by filtration to yield 120.6 g of desired product with chemical purity of ca. 98 %. After further recrystalliza- tion using the same procedure the desired product BNAD4PODCN was obtained with chemical purity of > 99.2 %. m.p. (DSC): 215.3 °C. Example 5: 2,2'-bis[(phenanthren-9-yl)oxy]-1,1'-binaphthalene (D9PNBNA, compound of formula (Ia), with k and l = 0, Ar1and Ar2= 9-phenanthrenyl, L1and L2= single bond and p and q = 0; compound 27 of table A) To a solution of [1,1'-binaphthalene]-2,2'-diol (43.4 g; 150 mmol) in DMF (240 g) K2CO3(62.4 g), 9-bromophenanthrene (97.4 g; 450 mmol), CuI (2.3 g; 12 mmol) and Fe(acac)3(2.12g; 6 mmol) were added. The mixture was stirred under argon at reflux for 59 h until TLC (eluent: cyclohexane / ethyl acetate = 3 / 1) showed a complete con- version. The mixture was cooled to room temperature and slowly added to 1 L of water under stirring. The resulting mixture was stirred at room temperature for 16 h. The formed solid was collected by filtration, subsequently washed with isopropanol (2×50 mL) and methanol (2×50 mL) and dryed at 60°C. The obtained solid material (130 g) was stirred in methanol (850 g) at room temperature for 1 h. After filtration and drying 100.5 g of 2,2'-bis[(phenanthren-9-yl)oxy]-1,1'-binaphthalene was obtained. This crude product was taken up in trichloromethane (500 g). To the obtained solution activated charcoal (5 g) was added and the mixture was stirred at room temperature for 30 min. The solution was filtered over celite to remove the activated charcoal. The obtained clear solution was concentrated to 30% under reduced pressure. Then, methanol (400 g) was added and the mixture was concentrated to half under reduced pressure. The precipitate was collected by filtration, washed with methanol and dried at 60°C to yield the title compound (D9PNBNA) with a chemical purity of 97.5 %. The material was fur- ther purified by crystallization from 2-methyl-tetrahydrofurane (200 mL) to yield 70.4 g of D9PNBNA. M / REUCTR-054-PC 801H NMR (80 MHz, CDCl3): δ = 8.66 (t, 4 H); 8.15 – 7.13 (m, 24 H); 6.90 (s, 2 H) ppm. 2.3 Refractive indices nD of monomers of formula (I): The following table B lists refractive indices of some monomers of formula (I) that were calculated using the software ACD / ChemSketch 2012 (Advanced Chemistry De- velopment, Inc.). The individual monomers are identified in table B by their names and their entry numbers in table A. Table B 3. Preparation of resins compositions 3.1 Analytics relating to resins and resin compositions: Refractive index (nD): The refractive index was measured using a disk shaped test piece with a thickness of 3 mm made by resin or resin composition as a test piece according to JIS B 7071- 2:2018. The measurement was conducted at 23○C using the refractive index measure- ment device below. Refractive index measurement device: M / REUCTR-054-PC 81 KPR-3000 manufactured by Shimadzu Corporation Abbe number A disk shaped test piece with a thickness of 3 mm which is same as the test piece used in the refractive index measurement was used. The refractive index values were meas- ured using the refractive index measurement device below at 23°C and at wavelengths of 486 nm, 589 nm and 656 nm. Then, the Abbe number was calculated using the be- low-described formula. Refractive index measurement device: KPR-3000 manufactured by Shimadzu Corporation ^ = (nD- 1) / (nF- nC) nD: refractive index at a wavelength of 589 nm nC: refractive index at a wavelength of 656 nm nF: refractive index at a wavelength of 486 nm Glass transition temperature (Tg): The glass transition temperature was measured by differential scanning calorimetry (DSC) using a 10°C / minute heating program according to JIS K7121-1987. Differential scanning calorimetry device: X-DSC7000 manufactured by Hitachi High-Tech Science Corporation Molecular weight The molecular weight distribution of the resin molecules, in particular the values of the weight average molecular weight (Mw) of the resins can be measured by the gel per- meation chromatography (GPC) method and calculated by the standard polystyrene conversion aproach. For example, the following devices, columns and measurement conditions can be used: GPC device: HLC-8420GPC (from Tosoh Corporation); Columns: three TSKgel SuperHM-M (from Tosoh Corporation), one guard column SuperHM-M (from Tosoh Corporation), one TSKgel SuperH-RC (from Tosoh Corporation); Detection Device: RI detection Standard polystyrene: PstQuick C as standard polystyrene kit (from Tosoh Corpora- tion); Eluent: tetrahydrofuran; Flow rate of eluent: 0.6 ml / min; M / REUCTR-054-PC 82 Column temperature: 40°C. The number average molecular weight (Mn) values can be calculated using similar methods to those used for measuring the Mw values described above. The polystyrene converted weight average molecular weights (Mw) and number average molecular weights (Mn) can be calculated using a previously prepared standard curve of polysty- rene. Specifically, the standard curve can be prepared using a standard polystyrene for which the molecular weight is known (“PStQuick C” from Tosoh Corporation). Further, a calibration curve can be obtained by plotting the elution time and molecular weight value of each of the peaks based on the measured data of the standard polystyrene, and conducting three-dimensional approximation. The values for Mw and Mn can be calculated based on the following calculation formulae: In the calculation formulae, “i” represents the “i”th dividing point, “Wi” represents the molecular weight (g) of the polymer at the “i”th dividing point, “Ni” represents the number of the molecules of the polymer at the “i”th dividing point, and “Mi” represents the molecular mass at the “i”th dividing point. The molecular mass (M) represents the value of the molecular mass of polystyrene at the corresponding elution time in the calibration curve. Contents of low molecular weight compounds (CLWC) The contents of low molecular weight compounds represent area ratios of compounds with the MWvalues lower than 1.000 on GPC analysis. Therefore, contents of low mo- lecular weight compounds can be determined according to the following formula: ^^^^^^^^(%) =the total area of peaks of compounds with Mw lower than 1.000 on GPC analysis ^^100 (the total area of all peaks of compounds on GPC analysis) The GPC analysis of the low molecular weight compounds can be carried out as de- scribed above for measuring the molecular weight of the thermoplastic resins. Birefringence The values of ^n (birefringence) can be determined as follows: a cast film of 0.1 mm thickness is cut out into a square of 5.0 cm per side, and the film is then clamped at the both ends with chucks (distance between the chucks: 3.0 cm), stretched 1.5-fold M / REUCTR-054-PC 83 at a temperature of the polycarbonate resin’s Tg + 20^C and measured for phase dif- ference (Re) at 589 nm using an ellipsometer M-220 (JASCO Corporation, Japan), fol- lowed by calculation according to the following equation: ^n = Re / d ^n: orientation birefringence Re: phase difference d: thickness The criteria of birefringence (^n) can be, for example, as shown in the table below. 3.2 Preparations Examples: 3.2.1 Resin Preparation Polymerisation Example 1: Preparation of the thermoplastic polycarbonate Resin A As materials, 14.6245 g (0.0272 mol) of 2,2'-((9H-fluorene-9,9-diyl)bis(naphthalene- 6,2-diyl))bis(ethan-1-ol) (BNEF), 11.4371 g (0.0305 mol) of 2,2'-bis(2-hydroxyethoxy)- 1,1'-binaphthyl(BNE), 5.3555 g (0.0102 mol) of 2,2'-((6,6'-diphenyl-[1,1'-binaphtha- lene]-2,2'-diyl)bis(oxy))bis(ethan-1-ol) (DPBN), 14.9768 g (0.0699 mol) of diphenylcar- bonate (DPC) and 0.5628×10-4g (0.6700×10-6mol) of sodium hydrogen carbonate were put into a 300 milliliter reactor with a stirrer and a distillation device. The reactor was flushed with nitrogen and the inside pressure was set to 101.3 kPa. The reactor was immersed in an oil bath at 180 °C and then the ester exchange reac- tion started. Stirring of the mixture was started 5 minutes after the start of the reac- tion and 20 minutes later the pressure was reduced from 101.3 kPa to 93.33 kPa over 10 minutes. 10 Minutes later, the oil bath was heated to 190 °C over 10 minutes. Af- ter 10 minutes, the pressure of the reaction mixture was reduced from 93.33 kPa to 26.66 kPa over 10 minutes. Then, the oil bath was heated from 190 °C to 210 °C and the pressure was further reduced to 24.00 kPa over 10 minutes. After that, the oil bath was heated to 220 °C and the pressure was reduced to 20.00 kPa over 10 minutes. Then, the oil bath was heated to 240 °C and the pressure was reduced to 17.33 kPa over 10 minutes. After 30 minutes, the pressure was reduced to 0 kPa, and these con- ditions were afterwards maintained for 30 minutes. Finally, the pressure was increased M / REUCTR-054-PC 84 back to 101.3 kPa by introducing nitrogen into the reactor to obtain a polycarbonate resin (Resin A). The characteristics of the obtained resin are summarized in Table 1 below. The following diol monomers BNEF, BNE and DPBN were used for preparing the ther- moplastic polycarbonate Resin A, see Polymerisation Example 1 above, and the diol monomers BNEF and BNE were used for preparing Resin B, see Polymerisation Exam- ple 2 below. Polymerisation Example 2: Preparation of the thermoplastic polycarbonate Resin B As materials, 26.2625 g (0.046 mol) of 2,2'-((9H-fluorene-9,9-diyl)bis(naphthalene-6,2- diyl))bis(ethan-1-ol) (BNEF), 7.5267 g (0.0203 mol) of 2,2'-bis(2-hydroxyethoxy)-1,1'- binaphthyl (BNE), 14.9768 g (0.0699 mol) of diphenylcarbonate (DPC) and 0.5628×10-4g (0.6700×10-6mol) of sodium hydrogen carbonate were put into a 300 milliliter reactor with a stirrer and a distillation device. The reactor was flushed with ni- trogen and the inside pressure was set to 101.3 kPa. The reactor was immersed in an oil bath at 180 °C and then the ester exchange reac- tion started. Stirring of the mixture was started 5 minutes after the start of the reac- tion and the oil bath was heated to 200 °C over 10 minutes. 20 minutes later, the pressure was reduced from 101.3 kPa to 93.33 kPa over 10 minutes. After 50 minutes, the pressure of the reaction mixture was reduced from 93.33 kPa to 26.66 kPa over 10 minutes. 10 Minutes later, the oil bath was heated from 200 °C to 220 °C over 10 minutes and it was further heated to 230 °C over 10 minutes. Then, the oil bath was heated to 250 °C and the pressure was reduced to 24.00 kPa over 10 minutes. After that, the pressure was reduced to 17.33 kPa over 10 minutes. Then, the oil bath was heated to 270 °C and the pressure was reduced to 17.33 kPa over 20 minutes. After 20 minutes the pressure was reduced to 0 kPa over 30 minutes. These conditions were afterwards maintained for 30 minutes. Finally, the pressure was increased back to M / REUCTR-054-PC 85 101.3 kPa by introducing nitrogen into the reactor to obtain the polycarbonate resin (Resin B). The characteristics of the obtained resin are summarized in Table 1 below. Table 1 3.2.2 Preparation of Resin Compositions Example 5: Composition of Resin A and Compound DBBNABHBNA as additive As materials, 5.4755 g of the polycarbonate resin obtained by Polymerization Example 1 (Resin A) and 1.8209 g of 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1- ethyloxy]-1,1'-binaphthalene (DBBNABHBNA, a compound of formula (Ia)) were put into a 10 milliliter reactor with a stirrer and a distillation device. The reactor was flushed with nitrogen and the inside pressure was set to 101.3 kPa. The reactor was immersed in an oil bath at 260 °C. Stirring of the mixture at 200 rpm was started 10 minutes after the start of the heating, and 10 minutes later the pres- sure was reduced from 101.3 kPa to 26.7 kPa. These conditions were then maintained for 30 minutes. Finally the pressure was increased back to 101.3 kPa by introducing ni- trogen into the reactor to obtain the desired polycarbonate resin composition. The characteristics of the obtained resin composition are summarized in Table 2 below. Example 6: Composition of Resin B and Compound DBBNABHBNA as additive As materials, 6.0348 g of the polycarbonate resin obtained by Polymerization Example 2 (Resin B) and 2.0238 g 2,2'-bis[2-(2-benzyloxy-1,1’-binaphthyl-2’-oxy)-1-ethyloxy]- 1,1'-binaphthalene (DBBNABHBNA, a compound of formula (Ia)) were put into a 10 milliliter reactor with a stirrer and a distillation device. The reactor was flushed with ni- trogen and the inside pressure was set to 101.3 kPa. The reactor was immersed in an oil bath at 260 °C. Stirring of the mixture at 10 rpm was started 10 minutes after the start of the heating, and 15 minutes later the oil bath M / REUCTR-054-PC 86 was heated from 260 °C to 270°C over 10 minutes. Then, the stirring speed was in- creased to at 100 rpm. 15 Minutes later the stirring speed was further increased to 150 rpm. These conditions were afterwards maintained for 15 minutes to obtain the de- sired polycarbonate resin composition. The characteristics of the obtained resin composition are summarized in Table 2 below. Comparative Example 1 depicted in Tables 2 to 5 is the polycarbonate resin obtained in Polymerization Example 1 (Resin A). The characteristics of the resin are summarized in Tables 2 to 5. Comparative Example 2 depicted in Tables 2 and 3 is the polycarbonate resin obtained in Polymerization Example 2 (Resin B). The characteristics of the resin are summarized in Tables 2 and 3. Table 2 DBBNABHBNA Example 7: Composition of Resin A and Compound BNAD4PODCN as additive The composition resin was prepared in analogy to the procedure of Example 5 using Resin A and BNAD4PODCN as additive compound of the formula (Ia). M / REUCTR-054-PC 87 The characteristics of the obtained resin composition are summarized in Table 3 below. Example 8: Composition of Resin B and Compound BNAD4PODCN as additive The composition resin was prepared in analogy to the procedure of Example 6 using Resin B and BNAD4PODCN as additive compound of the formula (Ia). The characteristics of the obtained resin composition are summarized in Table 3 below. Table 3 Example 9: Composition of Resin A and Compound DBNBNA as additive The composition resin was prepared in analogy to the procedure of Example 5 using Resin A and DBNBNA as additive compound of the formula (Ia). The characteristics of the obtained resin composition are summarized in Table 4 below. M / REUCTR-054-PC 88 Table 4 DBNBNA Example 10: Composition of Resin A and Compound DBBNAE as additive The composition resin was prepared in analogy to the procedure of Example 5 using Resin A and DBBNAE as additive compound of the formula (Ia). The characteristics of the obtained resin composition are summarized in Table 5 below. Table 5 DBBNAE

Claims

1. M / REUCTR-054-PC 89 We claim:

1. The use of a compound of the formula (I) or a mixture thereof where A1and A2are identical or different and independently selected from C1-C6- alkylene which are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'", X1and X2are identical or different and independently selected from the group consisting of O, C(=O), O-C(=O), S and SO2; Ar1is selected from the group consisting of a mono- or polycyclic aryl having from 6 to 50 carbon atoms as ring members and a mono- or polycyclic hetaryl having a total of 5 to 50 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms, where mono- or polycyclic aryl and mono- or polycyclic hetaryl are unsubstituted or carry 1, 2, 3 or 4 radicals RAr; Ar2is selected from the group consisting of a mono- or polycyclic aryl having from 6 to 50 carbon atoms as ring members and a mono- or polycyclic hetaryl having a total of 5 to 50 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms, where mono- or polycyclic aryl and mono- or polycyclic hetaryl are unsubstituted or carry 1, 2, 3 or 4 radicals RAr; M / REUCTR-054-PC 90 L1, L2are identical or different and independently selected from a single bond and C1-C6-alkylene which is unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'", R1and R2are identical or different and independently selected from the group consisting of halogen, C1-C20-alkyl, C1-C20-alkoxy, C1-C20-alkyl, C5-C20- cycloalkyl, C6-C20-aryl, C5-C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulphur and oxygen, -C≡C-Rh1, where Rh1 is selected from C6-C20-aryl and C5-C20-hetaryl having 1 or more atoms selected from nitrogen, sulfur and oxygen; C2-C3-alkynyl, CN, R11, OR11, CHsR'3-s, NR112, C(O)R and CH=CHR'', it being possible that R1and R2are identical or different if p+q>1, where s on each occurrence is 0, 1 or 2; k is 0 or 1; l is 0 or 1; p and q are identical or different and independently 0, 1 or 2; RAris selected from the group consisting of CN, R, OR, CHtR'3-t, NR2 and CH=CHR'', where RArmay be identical or different if more than one is present on the same (het)arylene group, where t on each occurrence is 0, 1 or 2; R is selected from the group consisting of C1-C20-alkyl, CN, benzyl, C6-C20-aryl, C5-C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulfur and oxygen, where benzyl, C6-C20-aryl and C5-C20-hetaryl, are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R11is selected from the group consisting of C1-C20-alkyl, benzyl, C6-C20-aryl, C5- C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulfur and oxygen, where benzyl, C6-C20-aryl and C5-C20-hetaryl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R' is selected from the group consisting of phenyl, naphthyl, phenanthrenyl and triphenylenyl, where phenyl, naphthyl, phenanthrenyl and triphenylenyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; M / REUCTR-054-PC 91 R'' is selected from hydrogen, methyl, phenyl and naphthyl, where phenyl and naphthyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; and R'" is selected from the group consisting of phenyl, halogen, CN, OCH3, CH3, N(CH3)2 and C(O)CH3, as an additive for resin.

2. The compound of the formula (I) as defined in claim 1, provided that at least one of the following conditions 2.1 or 2.2 are met: 2.1 p+q =1, 2 or 3; 2.2 k+l = 1 or 2; 2.3 k=l = 0, and at least one of Ar1and Ar2are selected from 2-naphthyl, phenanthrene-9-yl, 9H-fluoren-2-yl, dibenzo[b,d]thiophen-2-yl, dibenzo[b,d]thiophen-4-yl, dibenzo[b,d]furan-2-yl, dibenzo[b,d]furan- 4-yl, thianthrene-1-yl, thianthrene-2-yl, 2-triphenylenyl and thiophen- 3-yl; 3. The use of claim 1 or the compound of claim 2, where formula (I) is represented by formula (Ia): where Ar1, Ar2, A1, A2, X1, X2, L1, L2, R1, R2, k, l, p and q are as defined in claim 1 or in claim 2.

4. The use or the compound of any one of the preceding claims, where A1and A2are selected from C1-C3-alkylene which is unsubstituted and where A1and A2are in particular CH2-CH2.

5. The use or the compound of any one of the preceding claims, where X1and X2are selected from O, O-C(=O), C(=O) and S and where in particular both X1and X2are O. M / REUCTR-054-PC 926. The use or the compound of any one of the preceding claims, where Ar1 and Ar2are independently selected from the group consisting of a mono- or polycyclic aryl having from 6 to 36 carbon atoms as ring members and a mono- or polycyclic hetaryl having a total of 5 to 36 atoms, which are ring members, where polycyclic aryl and polycyclic hetaryl are unsubstituted or carry 1, 2, or 3 substituents RAr.

7. The use or the compound of any one of the preceding claims, where Ar1is polycyclic aryl having from 10 to 36 carbon atoms as ring members which is unsubstituted or carries 1, 2, or 3 substituents RAr.

8. The use or the compound of claim 7, where Ar1is phenyl, naphthyl or phenanthrenyl, where phenyl, naphthyl and phenanthrenyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; or Ar1is a group represented by the following formula (Ar1-a) where # represents a connection point to L1; a and b are identical or different and independently 0 or 1 and RAr1and RAr2are identical or different and are as defined for RAr.

9. The use or the compound of any one of the preceding claims, where Ar2is mono- or polycyclic aryl having from 6 to 36 carbon atoms as ring members which is unsubstituted or carries 1, 2, or 3 substituents RAr.

10. The use or the compound of claim 9, where Ar2is phenyl, naphthyl or phenanthrenyl, where phenyl, naphthyl and phenanthrenyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; or Ar2is a group represented by the following formula (Ar2-a) M / REUCTR-054-PC 93 where # represents a connection point to L2; a and b are identical or different and independently 0 or 1 and RAr1and RAr2are identical or different and are as defined for RAr.

11. The use or the compound of any one of the preceding claims, where RAris selected from the group consisting of R, OR and NR2, where RArmay be identical or different if more than one RAris present on the same (het)aryl group; and R is in particular selected from the group consisting of C1-C4-alkyl, phenyl, benzyl, and naphthyl.

12. The use or the compound of any one of the preceding claims, where k+l is 1 or 2 and both L1and L2are single bonds or where k+l is 0 and both L1and L2are single bonds or CH2and mixtures thereof.

13. The use or the compound of any one of the preceding claims, where R1and R2, if present, are independently selected from the group consisting of halogen, C2-C3- alkynyl, CN, R11and OR11, where R11is in particular selected from the group consisting of benzyl, mono- or polycyclic aryl having from 6 to 18 carbon atoms as ring atoms or are mono- or polycyclic hetaryl having a total of 5 to 18 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryl are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetaryl are carbon atoms, where aryl and hetaryl are unsubstituted or carry a substituent R'", and where p and q are independently 0 or 1.

14. The use or the compound of any one of the preceding claims, where p = 0 and q is 0.

15. The use or the compound of any one of the preceding claims, where formula (I) is represented by the following formula (Ib), where Ar1, Ar2, R1, R2, L1, L2, k, l, p’ and q’ are as defined in one row of table A: M / REUCTR-054-PC 94 Table A: M / REUCTR-054-PC 95 Ph: phenyl 4-CN-Ph: 4-cyanophenyl Ar1-1: 1-(2-benzyloxy-1-naphthyl)naphthalene-2-yl Ar2-1: 1-(2-benzyloxy-1-naphthyl)naphthalene-2-yl Ar1-2: 4-CN-naphth-1-yl Ar2-2: 4-CN-naphth-1-yl Ar1-3: dibenzo[b,d]thiophen-2-yl Ar2-3: dibenzo[b,d]thiophen-2-yl Ar1-4: dibenzo[b,d]thiophen-4-yl Ar2-4: dibenzo[b,d]thiophen-4-yl Ar1-5: dibenzo[b,d]furan-2-yl Ar2-5: dibenzo[b,d]furan-2-yl Ar1-6: dibenzo[b,d]furan-4-yl Ar2-6: dibenzo[b,d]furan-4-yl Ar1-7: 9H-fluoren-2-yl Ar2-7: 9H-fluoren-2-yl Ar1-8: 2-triphenylenyl Ar2-8: 2-triphenylenyl Ar1-9: phenanthren-9-yl Ar2-9: phenanthren-9-yl Ar1-10: thianthren-1-yl Ar2-10: thianthren-1-yl Ar1-11: thianthren-2-yl Ar2-11: thianthren-2-yl 16. A resin composition comprising at least one resin and at least one compound of the formula (I) as defined in any one of claims 1 to 15.

17. The resin composition of claim 16, where the resin is a thermoplastic resin, in particular a polycarbonate, polyestercarbonate or polyester or a mixture thereof, especially an aromatic polycarbonate, an aromatic polyestercarbonate or an aromatic polyester or a mixture thereof.

18. The resin composition of any one of claims 16 or 17, where the resin comprises at least one of a structural unit represented by formulae (II-1) and (II-2) below; M / REUCTR-054-PC 96 where # represents a connection point to a neighbouring structural unit; R0are independently selected from C1-C6-alkylene which are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'", where R'" is selected from the group consisting of phenyl, halogen, OCH3, CH3, N(CH3)2 and C(O)CH3; a1, b1, a2 and b2 are independently selected from 0 to 10; A1a, A2aA1band A2bare independently selected from the group consisting of O, C=O, C(O)O, S and SO2; R1and R2are independently selected from the group consisting of halogen, C1- C20-alkyl, C1-C20-alkoxy, C1-C20-alkyl, C5-C20-cycloalkyl, C6-C20-aryl, C5-C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulphur and oxygen, -C≡C-Rh1, where Rh1 is selected from C6-C20-aryl and C5-C20-hetaryl having 1 or more atoms selected from nitrogen, sulfur and oxygen; C2-C3-alkynyl, CN, R11a, OR11a, CHsR'3-s, NR11a2, C(O)R and CH=CHR'', it being possible that R1and R2are identical or different if m1+n1>1 or m2+n2>1, where s on each occurrence is 0, 1 or 2; R11ais selected from the group consisting of C1-C20-alkyl, benzyl, C6-C20-aryl, C5- C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulfur and oxygen, where benzyl, C6-C20-aryl and C5-C20-hetaryl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; M / REUCTR-054-PC 97 m1and n1are independently selected from 0 to 6; m2and n2are independently selected from 0 to 4; Z1and Z2are independently selected from a single bond and fluorene ring which is unsubstituted or substituted by 1, 2, 3, 4 or 5 identical or different radicals R'"', where R'"' is selected from the group consisting of halogen, methyl, methoxy, CN, N(CH3)2, C(O)CH3, phenyl, naphthyl and phenanthrenyl; and where R, R’, R’’ and R’’’ are as defined in claim 1.

19. The resin composition of claim 18, where A1a, A2aA1band A2bare independently selected from the group consisting of O, C=O and C(O)O.

20. The resin composition of claims 18 or 19, where R0are independently selected from C1-C6-alkylene which are unsubstituted.

21. The resin composition of any one of claims 18 to 20, where m1and n1are independently selected from 0 and 1; and m2and n2are independently selected from 0 and 1.

22. The resin composition of any one of claims 18 to 21, where Z1and Z2are independently selected from a single bond and unsubstituted fluorene ring.

23. The resin composition of any one of claims 18 to 22, where a1, b1, a2 and b2 are independently selected from 0 to 2.

24. The resin composition of any one of claims 16 to 23, where the resin comprising a structural unit represented by formula (II-3) below where # represents a connection point to a neighboring structural unit; M / REUCTR-054-PC 98C1 and C2 are independently selected from the group consisting of a mono- orpolycyclic arylene having from 6 to 26 carbon atoms as ring members and a mono- or polycyclic hetarylene having a total of 5 to 26 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetarylene are selected from nitrogen, sulfur and oxygen, while the remainder of these ring member atoms of hetarylene are carbon atoms, where mono- or polycyclic arylene and mono- or polycyclic hetarylene are unsubstituted or carry 1, 2, 3 or 4 radicals RAr; RAris selected from the group consisting of CN, R, OR, CHtR'3-t, NR2and CH=CHR'', where RArmay be identical or different if more than one is present on the same (het)arylene group, where t on each occurrence is 0, 1 or 2; R is selected from the group consisting of C1-C4-alkyl, phenyl, naphthyl, phenanthrenyl and triphenylenyl, where phenyl, naphthyl, phenanthrenyl and triphenylenyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R' is selected from the group consisting of phenyl, naphthyl, phenanthrenyl and triphenylenyl, where phenyl, naphthyl, phenanthrenyl and triphenylenyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R'' is selected from hydrogen, methyl, phenyl and naphthyl, where phenyl and naphthyl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; R'" is selected from the group consisting of phenyl, halogen, OCH3, CH3, N(CH3)2 and C(O)CH3; R1and R2are independently selected from the group consisting of halogen, C1- C20-alkyl, C1-C20-alkoxy, C1-C20-alkyl, C5-C20-cycloalkyl, C6-C20-aryl, C5-C20- hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulphur and oxygen, -C≡C-Rh1, where Rh1 is selected from C6-C20-aryl and C5-C20-hetaryl having 1 or more atoms selected from nitrogen, sulfur and oxygen; C2-C3- alkynyl, CN, R11a, OR11a, CHsR'3-s, NR11a2, C(O)R and CH=CHR'', it being possible that R1and R2are identical or different if p+q>1, where s on each occurrence is 0, 1 or 2; R11ais selected from the group consisting of C1-C20-alkyl, benzyl, C6-C20-aryl, C5- C20-hetaryl having 1, 2, 3 or 4 atoms selected from nitrogen, sulfur and oxygen, where benzyl, C6-C20-aryl and C5-C20-hetaryl are unsubstituted or substituted by 1, 2, 3 or 4 identical or different radicals R'"; M / REUCTR-054-PC 99 p and q are independently 0, 1 or 2; and A1cand A2care independently selected from the group consisting of O, -CH2O, C=O, C(O)O, S and SO2 and where R, R’, R’’ and R’’’ are as defined in claim 1.

25. The resin composition of claim 24, which is of the formula (II-3b), where C1, C2, A1ｃ, A2ｃ, R1and R2are as defined in claim 24.

26. The resin composition of any one of claims 16 to 25, where the structural unit of the formula (II-1), (II-2) or (II-3), wherein two O atoms in A1a, A2a, A1b, A2bA1cor A2care connected to one of the structures represented by formulae (III-1) to (III-5) below, (III-1) (III-2) (III-3) (III-4) (III-5) where # represents a connection point to a neighboring structural unit.

27. The resin composition of any one of claims 16 to 26, where the resin is selected from copolycarbonate resins, copolyestercarbonate resins and copolyester resins, where the thermoplastic resin in addition to structural units represented by formula (II-1), (II-2) or (II-3) comprises a structural unit of the formula (V), #-O-Rz-A3-Rz-O-#- (V) M / REUCTR-054-PC 100 where # represents a connection point to a neighbouring structural unit; A3is a polycyclic radical bearing at least 2 benzene rings, wherein the benzene rings may be connected by W and / or directly fused to each other and / or fused by a non-benzene carbocycle and / or fused by two non- benzene carbocycles that are linked via a linker L, where A3is unsubstituted or substituted by 1, 2 or 3 radicals Raa, which are selected from the group consisting of halogen, C1-C6-alkyl, C5-C6-cycloalkyl, phenyl, naphthyl, 1,2-dihydroacenaphthylenyl, phenanthrenyl, pyrenyl, triphenylenyl, benzo[b]furanyl, dibenzo[b,d]furanyl, benzo[b]thienyl, dibenzo[b,d]thienyl and thianthrenyl; W is selected from the group consisting of a single bond, O, C=O, S, S(O), SO2, CH2, CH-Ar, CAr2, CH(CH3), C(CH3)2 and a radical of the formula (A') where Q’ represents a single bond, O, C=O, CH2, S or SO2; and R7a, R7b, independently of each other are selected from the group consisting of hydrogen, fluorine, CN, R, OR, CHvR’3-v, NR2, C(O)R and C(O)NH2, where R and R’ are as defined in claim 1 and v is 0, 1 or 2; and * represents a connection point to a benzene ring; L is selected from a single bond, C1-C4-alkylene, C4-C7-cycloalkylene, C4-C7- cycloalkylenedimethylene, phenylenedimethylene, where L is unsubstituted or substituted by 1 or 2 radicals RL, which are selected from the group consisting of C1-C4-alkyl, halogen, C1-C4-haloalkyl, C4-C7-cycloalkyl and phenyl, Ar is selected from the group consisting of mono- or polycyclic aryl having from 6 to 26 carbon atoms as ring atoms and mono- or polycyclic hetaryl having a total of 5 to 26 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryl are selected from nitrogen, sulphur and oxygen, while the remainder of these ring member atoms of M / REUCTR-054-PC 101 hetaryl are carbon atoms, where Ar is unsubstituted or substituted by 1, 2 or 3 radicals Rab, which are selected from the group consisting of halogen, phenyl and C1-C4-alkyl; Rzis a single bond, Alk3, O-Alk4-, O-Alk4-[O-Alk4-]w- or O-Alk5-C(O)- where O is bound to A3, and where w is an integer from 1 to 10; Alk3is C1-C4-alkandiyl; Alk4is C2-C4-alkandiyl; and Alk5is C1-C4-alkandiyl, and where R and R’ are as defined in claim 1.

28. The resin composition of claim 27, where the structural unit of the formula (V) is represented by one of the following formulae V-1 to V-8: M / REUCTR-054-PC 102 a and b are 0, 1, 2 or 3, in particular 0 or 1; a’ and b’ are 0, 1, 2 or 3, in particular 0 or 1; c and d are 0, 1, 2, 3, 4 or 5, in particular 0 or 1; e and f are 0, 1, 2, 3, 4 or 5, in particular 0 or 1; W’ is S, S(O), SO2, O, a single bond, CH2, CH(CH3) or C(CH3)2, in particular S, S(O), SO2 or C(CH3)2; and where Rz, Raa, Rab, R7a, R7band L are as defined for formula (V).

29. The resin composition of claim 27 or 28, where the molar ratio of the structural units of the formula (II-1), (II-2) or (II-3) is from 1 to 99 mol-%, preferably from 10 to 99 mol-%, in particular from 15 to 97 mol-%, based on the total molar amount of structural units of the formulae (II-1), (II-2) or (II-3) and (V) and where the molar ratio of the structural units of the formula (V) is from 1 to 99 mol-%, preferably from 1 to 90 mol-%, in particular from 3 to 85 mol-%, based on the total molar amount of structural units of the formulae (II-1), (II-2) or (II- 3) and (V).

30. The resin composition of any one of claims 16 to 29, which has a refractive index of 1.640 or higher. M / REUCTR-054-PC 103 31. The resin composition of claim 30, where the refractive index is 0.001 or more higher than that of a reference resin composition having the same composition but without the compound of any one of Claim 1 to 15.

32. The resin composition of any one of claims 16 to 31, which has an Abbe number of 24 or lower.

33. The resin composition of claim 32, where the Abbe number is 0.10 or more lower than that of a reference resin composition having the same composition but without the compound of any one of Claim 1 to 15.

34. The resin composition of any one of Claims 16 to 33, which has a glass transition temperature (Tg) of 90 to 185°C.

35. The resin composition of Claim 34, where the glass transition temperature (Tg) is 5℃ or more lower than that of a reference resin composition having the same composition but without the compound of any one of Claims 1 to 15.

36. The resin composition of any one of Claims 16 to 35, where the resin has a weight-average molecular weight of 10000 to 50000 as determined by gel permeation chromatography against a polystyrene standard.

37. The resin composition of any one of Claims 16 to 36, where the resin composition comprises 5 to 50 % by weight of at least one compound of formula (I) and 50 to 95 % by weight of the resin based on the total weight of the resin composition.

38. The resin composition of any one of Claims 16 to 37, which comprises 9% by weight or less of low molecular weight compounds other than the compounds of the formula (I) having molecular weight of less than 1000, based on the total weight of the thermoplastic resin.

39. An optical device made of the resin composition of any one of Claims 16 to 38.

40. Use of the compound of any one of claims 1 to 15, as an additive of the resin composition as defined in any one of claims 16 to 38.

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