Bipyrylidene, disulfide bipyrylidene and diselenide bipyrylidene and their uses

Abstract

The present invention relates to bipyrans, dithiobipyrans and diselenoidbipyrans according to formula (I), their use as light absorbers or infrared absorbers, and electronic or optoelectronic components comprising at least one compound according to formula (I).

Description

[0001] The present invention relates to bipyrans, dithiobipyrans and diselenoidbipyrans according to formula (I), their use as light absorbers or infrared absorbers, and electronic or optoelectronic components containing at least one compound according to formula (I).

[0002] Optoelectronic components have the property of converting light, particularly sunlight, into electricity or vice versa. These component categories include solar cells, OLEDs, and sensors, particularly photodetectors. Solar cells are optimized to convert the largest possible fraction of sunlight into electricity. Detectors, on the other hand, often operate with an externally applied voltage to achieve higher external quantum efficiency and faster response times within their detection range. This detection range can be within or beyond the visible light range.

[0003] Electronic components, such as organic field-effect transistors (OFETs), can consist of very thin insulating films and organic semiconductor layers in addition to three contacts (source, drain, and gate), and their drain voltage / current characteristic curve depends largely on the gate voltage.

[0004] The development of compounds for electronic and optoelectronic components is currently the subject of intensive research. The aim is to develop and investigate compounds that have improved property characteristics, in particular with regard to absorption range, electromobility and component efficiency.

[0005] Strzelecka et al. disclose a study of the optical and electrical properties of unsubstituted and substituted dipyranylenes and dithiopyranylenes (Strzelecka et al., 1979). The compounds are used to prepare TCNQ molecular complexes.

[0006] Fabre et al. disclose dipyranylenes substituted by various aromatic groups, in particular by phenyl groups, p-tolyl groups or thiophene groups (Fabre et al., 1976).

[0007] Mabon et al. describe a process for the preparation of different tetrasubstituted dipyrans, in particular symmetrical and unsymmetrical dipyrans substituted by methyl groups or aryl groups, such as phenyl groups, thiophene groups or anisyl groups (Mabon et al., 1989).

[0008] A variant for improving the properties of optoelectronic components, such as photovoltaic cells and photodetectors, in particular near infrared (NIR) sensors and infrared (IR) sensors, provides the use of so-called charge transfer transitions. Charge transfer transitions (CT, ) are divided into intramolecular and intermolecular charge transfer transitions. A charge transfer transition is a complete or almost complete charge transfer from a donor compound to an acceptor compound. If both compounds are anchored in the same molecule, an intramolecular charge transfer transition is present. If different (discrete) molecules or ions, which can also be loosely coupled by coordination interactions, act as donor and acceptor compounds, this is also referred to as intermolecular charge transfer. Intermolecular charge transfer transitions typically result in electrostatically bound donor-acceptor complexes.

[0009] An intermolecular charge transfer state is a weakly bound state between an excited electron in the LUMO (or a state existing at a higher energy) and a hole in the HOMO (or a state existing at a lower energy), wherein the hole and electron are located on spatially separated molecules. Preferably, a charge transfer state is formed at the interface between the donor compound and the acceptor compound. Subsequently, the donor compound, excited by absorption of electromagnetic radiation, transfers negative charge from the LUMO to the LUMO of the acceptor compound via interchromophore charge transfer or enters the ground state via recombination.

[0010] EP 3152785 B1 and Siegmund et al. describe near-infrared photodetectors based on molecular charge transfer absorption (Siegmund et al., 2017), in particular using optical microcavities to improve the external quantum efficiency (EQE), which is typically negligible in the spectral range of charge transfer absorption, by a factor of more than 40. Siegmund et al. describe EQEs exceeding 20% and spectral linewidths as low as 36 nm and resonant wavelengths between 810 nm and 1550 nm, based on the use of donor materials with high HOMO levels and C 60 - mixtures of fullerenes, especially ZnPc:C 60 and TPDP:C 60 .

[0011] EP 3152785 B1 describes the detection of electromagnetic signals in the wavelength range from 780 nm to 10 μm using a donor compound and an acceptor compound, the donor compound being preferably selected from the group consisting of phthalocyanines such as zinc phthalocyanine or iron phthalocyanine; pyrans such as bipyranylene, in particular TPDP; fulvalenes such as tetrathiofulvalene, or aromatic amines such as N,N,N',N'-tetrakis(4-methoxyphenyl)-benzidine, 2,7-bis[N,N-bis(4-methoxy-phenyl)amino]9,9-spiro-bifluorene or 4,4',4"-tris(3-methylphenyl-phenylamino)triphenylamine), bisthiopyranylene, bipyridine or diketopyrrolopyrrole; the acceptor compound being preferably selected from the group consisting of fullerenes such as C 60 .

[0012] Bolag et al. disclosed a field-effect transistor based on tetraphenyldipyran (TPDP) and its sulfur-containing analogs (Bolag et al., 2009). Bolag et al. described the stability of the cations and dications of TPDP, the extended π system that facilitates intermolecular interactions, the simple preparation method, and the high absorption in the visible range. Bolag et al. also disclosed that the sulfur-containing compounds have higher performance than TPDP due to their higher crystallinity, and introduced halogen substituents to improve stability and solubility.

[0013] DE 102015101768 A1 discloses unsubstituted and substituted quinone-type aromatic compounds, polyaromatic compounds, heteroaromatic compounds or polyaromatic compounds, their possible use for optoelectronic components and the optoelectronic components and their use as IR absorbers in films and thin layers, in particular in thermally insulating glasses.

[0014] US 2011 / 0083730 A1 discloses symmetrical and asymmetrical compounds of formula (I) and their use in electronic and optoelectronic components

[0015]

[0016] Among them, X 1 and X 2 are independently selected from N, P, O, S, Se and Te, and R 1 and R 2 are independently selected from unsubstituted or substituted aromatic compounds and heteroaromatic compounds having 4 to 10 C atoms. As heteroaromatic compounds, thienyl groups and alkoxythienyl groups are disclosed, in particular furan group, pyrrole group, pyridine group, pyrazine group, pyrazolyl group, pyridazine group, pyrimidine group, triazole group, imidazole group, oxazole group, indene group, indazole group, quinolyl group and quinoxaline group.

[0017] Although improved efficiencies of optoelectronic components have been achieved through various means, the efficiencies and component lifetimes currently achieved are not sufficient for commercial use.

[0018] It is therefore an object of the present invention to provide organic photoactive compounds having a high absorption intensity.

[0019] Another object of the present invention is to provide an electronic or optoelectronic component with high efficiency.

[0020] According to the invention, this object is achieved by compounds according to formula (I)

[0021]

[0022] Among them, X 1 and X 2 are independently selected from oxygen, sulfur and selenium, wherein R 1 and R 2 are each independently selected from substituted thiophene groups and substituted selenophene groups.

[0023] Advantageously, the compounds according to the present invention have high thermal stability. Advantageously, the compounds according to the present invention can be sublimed in a high vacuum. Also advantageously, the compounds according to the present invention have photoactivity in the visible and infrared ranges. Advantageously, the compounds according to the present invention are electron donor compounds and particularly advantageously, the compounds according to the present invention have long-wave and strongly absorbing charge-transfer (CT) transitions together with suitable p-acceptor materials. The reason for the difference in absorption in the redder or longer-wave absorption range of the compounds according to the present invention having substituted thiophene groups and substituted selenophene groups in the CT state is the broadening and increase of the HOMO state, whereby the overlap with the LUMO energy is greater and also overlaps with the acceptor used.

[0024] In another embodiment, R 1 and R 2 Each independently selected from

[0025] where R 3 selected from C1 to C20 alkyl groups and C1 to C20 cycloalkyl groups, C1 to C20 perfluoroalkyl groups, C1 to C20 aryl groups and C1 to C20 heteroaryl groups, C1 to C20 alkoxy groups and C1 to C20 thioalkoxy groups, and primary, secondary and tertiary C1 to C20 alkylamino groups.

[0026] A "perfluoroalkyl group" is understood to be an alkyl group in which all hydrogen atoms are replaced by fluorine atoms. Preferably, the perfluoroalkyl group is selected from trifluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl, nonafluorobutyl, nonafluoro-tert-butyl and nonafluoroisobutyl.

[0027] A "primary alkylamino group" is understood to be a derivative of ammonia in which one hydrogen atom is replaced by an alkyl group, such as methylamine.

[0028] A "secondary alkylamino group" is understood to be an ammonia derivative in which the two hydrogen atoms are each replaced by an alkyl group, such as dimethylamine or ethylmethylamine.

[0029] A "tertiary alkylamino group" is understood to be an ammonia derivative in which each of the three hydrogen atoms is replaced by an alkyl group, such as trimethylamine or ethyldimethylamine.

[0030] In further embodiments, primary, secondary, and tertiary C1 to C20 alkylamine groups include cyclic amines, especially cyclic secondary amines, and ditoluidine.

[0031] In another embodiment, R 3 is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl, nonafluorobutyl, nonafluoro-tert-butyl, nonafluoroisobutyl, 2,2,2-trifluoroethyl, 2,2,3,3,3-pentafluoropropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, 2,2,3,3, 4,4,5,5,6,6,6-undecafluorohexyl, phenyl, benzyl, diphenyl, naphthyl, anthracenyl, phenanthrenyl, pyridyl, furyl, thienyl, thiazolyl, oxazolyl, imidazolyl, pyrimidinyl, thiazinyl, methoxy, ethoxy, propoxy, butoxy, pentyloxy, thiomethoxy, thioethoxy, thiopropoxy, thioisopropoxy, thiobutoxy, thioisobutoxy, t-butoxy, thiohexyloxy, thioisohexyloxy, amino, methylamino, butylamino, tolylamino, dimethylamino, diethylamino, methylphenylamino, methyltolylamino, pyrrolidine, piperidine, morpholine, thiomorpholine, and xylidine.

[0032] In a preferred embodiment, R 3 It is selected from unsubstituted or substituted C1 to C20 alkyl groups, particularly preferably selected from methyl, ethyl, propyl, butyl, pentyl and hexyl groups.

[0033] In one embodiment, R 1 With R 2 same.

[0034] In another embodiment, X 1 and X 2 It is oxygen and sulfur, oxygen and selenium, or sulfur and selenium.

[0035] In a preferred embodiment, X 1 and X 2 are each independently selected from sulfur and selenium.

[0036] In a preferred embodiment, X 1 and X 2 In a preferred embodiment, X 1 and X 2 is selected from oxygen, sulfur and selenium, particularly preferably, X 1 and X 2 For sulfur.

[0037] In a further embodiment, the compounds according to the invention are symmetrical, wherein R 1 With R 2 and X 1 With X 2 same.

[0038] Particularly preferred embodiments of the compounds according to the invention are the following individual compounds:

[0039] 2,2',6,6'-Tetrakis-(2-methylthienyl)-4,4'-bipyran,

[0040] 2,2',6,6'-Tetra-(2-ethylthienyl)-4,4'-bipyran,

[0041] 2,2',6,6'-Tetra-(2-propylthienyl)-4,4'-bipyran,

[0042] 2,2',6,6'-Tetra-(2-butylthienyl)-4,4'-bipyran,

[0043] 2,2',6,6'-Tetra-(2-pentylthienyl)-4,4'-bipyran,

[0044] 2,2',6,6'-Tetra-(2-hexylthienyl)-4,4'-bipyran,

[0045] 2,2',6,6'-tetrakis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-4,4'-bipyran,

[0046] 2,2',6,6'-Tetra-(2-heptylthienyl)-4,4'-bipyran,

[0047] 2,2',6,6'-Tetrakis-(2-methylthienyl)-4,4'-dithiopyran,

[0048] 2,2',6,6'-Tetra-(2-ethylthienyl)-4,4'-dithiopyran,

[0049] 2,2',6,6'-Tetrakis-(2-propylthienyl)-4,4'-dithiopyran,

[0050] 2,2',6,6'-Tetra-(2-butylthienyl)-4,4'-dithiopyran,

[0051] 2,2',6,6'-Tetra-(2-pentylthienyl)-4,4'-dithiopyran,

[0052] 2,2',6,6'-Tetrakis-(2-hexylthienyl)-4,4'-dithiopyran,

[0053] 2,2',6,6'-Tetra-(2-heptylthienyl)-4,4'-dithiopyran,

[0054] 2,2',6,6'-tetrakis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-4,4'-dithiopyran,

[0055] 2,2',6,6'-Tetrakis-(2-methylthienyl)-4,4'-diselenopyran,

[0056] 2,2',6,6'-Tetrakis-(2-ethylthienyl)-4,4'-diselenopyran,

[0057] 2,2',6,6'-Tetrakis-(2-propylthienyl)-4,4'-diselenopyran,

[0058] 2,2',6,6'-Tetra-(2-butylthienyl)-4,4'-diselenopyran,

[0059] 2,2',6,6'-Tetra-(2-pentylthienyl)-4,4'-diselenopyran,

[0060] 2,2',6,6'-Tetrakis-(2-hexylthienyl)-4,4'-diselenopyran,

[0061] 2,2',6,6'-Tetrakis-(2-heptylthienyl)-4,4'-diselenopyran, or

[0062] 2,2',6,6'-Tetrakis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-4,4'-diselenopyran.

[0063] The present invention also provides for the use of at least one compound according to formula (I) as a light absorber or infrared absorber, in particular in electronic or optoelectronic components, wherein X 1 and X 2 are independently selected from oxygen, sulfur and selenium, wherein R 1 and R 2 are each independently selected from substituted thiophene groups and substituted selenophene groups.

[0064] "Light" is understood to mean electromagnetic radiation having a wavelength in the range of 380 nm to 780 nm. "Infrared (IR)" is understood to mean electromagnetic radiation having a wavelength in the range of 780 nm to 1 mm. "Near infrared (NIR)" is understood to mean electromagnetic radiation having a wavelength in the range of 780 nm to 3 μm.

[0065] A “light absorber or infrared absorber” is understood to be a compound which is able to absorb at least a portion of electromagnetic radiation having a wavelength in the range from 380 nm to 1 mm.

[0066] "Optoelectronic component" is understood to be a component representing an interface between electrical and optical components. In an embodiment, the optoelectronic component is selected from organic solar cells (OSC), Batteries, organic integrated circuits (O-ICs), organic field-effect transistors (OFETs), organic thin film transistors (O-TFTs), organic light-emitting diodes (OLEDs), photodetectors, and IR sensors, especially infrared (IR) charge-transfer (CT) absorption sensors.

[0067] In various embodiments, the use of at least one compound according to the invention as a light absorber or infrared absorber in combination with an electron acceptor, preferably a fullerene, particularly preferably C 60 or C 70 Fullerene; or fullerene derivatives such as 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C 61 The (PCBM) combination is implemented as a photoactive mixed layer in optoelectronic components. Advantageously, after absorption of light or IR radiation by the compound according to the invention, electrons are transferred to an electron acceptor. Preferably, the electrons reach the electrode via an electron transport layer.

[0068] In other embodiments, the use as donor absorber materials in organic solar cells (OSCs), as hole transport materials (HTMs) in The present invention is implemented in batteries, in organic integrated circuits (O-ICs), in organic field effect transistors (OFETs), in organic thin film transistors (O-TFTs), in organic light emitting diodes (OLEDs), in photodetectors or IR sensors, in particular infrared (IR) charge transfer (CT) absorption sensors.

[0069] Preferably, at least one compound according to the invention is used in an infrared (IR) charge transfer (CT) absorption sensor. Advantageously, IR-CT absorption sensors containing the compound according to the invention achieve spectral line widths of at most 100 nm, preferably at most 50 nm, and particularly preferably at most 15 nm.

[0070] The present invention also provides for the use of at least one compound according to formula (I) in a method for detecting electromagnetic signals in the wavelength range from 780 nm to 10 μm, wherein X 1 and X 2 are independently selected from oxygen, sulfur and selenium, wherein R 1 and R 2 are each independently selected from substituted thiophene groups and substituted selenophene groups.

[0071] Preferably, the method is implemented as a method for detecting electromagnetic signals in the wavelength range of 780 nm to 10 μm, the method comprising the following steps:

[0072] a) providing an optoelectronic component, the optoelectronic component being arranged on a substrate, and

[0073] i. having two mirrors separated from each other and facing each other, the mirrors forming an optical microcavity,

[0074] ii. having a photoactive layer arranged between the mirror surfaces, the photoactive layer containing at least one compound according to formula (I) and one further compound,

[0075] Wherein, the additional compound is preferably selected from fullerenes, preferably C 60 or C 70 Fullerene, or a fullerene derivative, preferably 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C 61 (PCBM), wherein the energy difference between the HOMO energy of the compound according to formula (I) and the LUMO energy of the further compound is lower than 1.6 eV,

[0076] wherein the optical path length between the mirrors is equivalent to 25 to 75% of the wavelength of the signal to be detected, and

[0077] Among them, the energy equivalent range of the wavelength range of the electromagnetic signal to be detected is

[0078] - the energy difference defined by the HOMO energy of the compound according to formula (I) and the LUMO energy of the further compound, and

[0079] - the energy difference defined by the HOMO energy and the LUMO energy of the compound according to formula (I),

[0080] wherein the photoactive layer is aligned within the optical microcavity at a spatial intensity maximum of the wavelength of the electromagnetic signal to be detected between the mirror surfaces;

[0081] b) irradiating the optoelectronic component with an electromagnetic signal having a wavelength in the range of 780 nm to 10 mm;

[0082] c) intensifying the electromagnetic signal to be detected within the optical microcavity, wherein a direct interchromophore charge transfer of the compound according to formula (I) to the further compound occurs induced by the wavelength of the signal to be detected;

[0083] d) Convert electromagnetic signals into electrical signals.

[0084] Another aspect of the present invention relates to an electronic or optoelectronic component comprising at least one compound according to formula (I), wherein X 1 and X 2 are independently selected from oxygen, sulfur and selenium, wherein R 1 and R 2 are each independently selected from substituted thiophene groups and substituted selenophene groups.

[0085] In an embodiment, the optoelectronic component further comprises at least one additional compound, in particular an electron acceptor compound (acceptor compound), wherein the additional compound is selected from fullerenes, preferably C 60 or C 70 Fullerene, or a fullerene derivative, preferably 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C 61 (PCBM). Preferably, the optoelectronic component comprises at least one compound according to the invention and at least one further compound as a photoactive mixed layer.

[0086] In another embodiment, the optoelectronic components, in particular organic solar cells, have two or more photoactive layers (multi-node components), wherein the photoactive layers are usually arranged in individual solar cells that are processed mostly vertically directly on top of each other and are connected in series via so-called recombination contacts.

[0087] In various embodiments, optoelectronic components, in particular organic solar cells, contain the compounds according to the invention as light absorbers in a so-called cascade structure. The photoactive layer of the solar cell consists of a sequence of multiple donor molecules followed by multiple acceptor molecules (depending on the design, this can also be done in the reverse order as a pin or nip structure). In other embodiments, multiple donors can also be mixed with multiple acceptors to form the photoactive layer and thus cover a wider spectral range of sunlight.

[0088] Advantageously, the charge transfer strength of the optoelectronic device is two to three times greater than that of an optoelectronic device comprising tetraphenyldipyranylene (TPDP).

[0089] In one embodiment, the optoelectronic component according to the invention has an absorption range up to a wavelength of at least 1000 nm, preferably up to at least 1300 nm, particularly preferably up to at least 1600 nm.

[0090] In a preferred embodiment, the optoelectronic component according to the invention has an absorption range of 810 nm to 1665 nm, preferably 900 nm to 1300 nm.

[0091] In another embodiment, the optoelectronic component comprises an electrode consisting of: a metal, a conductive oxide, in particular indium tin oxide (ITO), ZnO:Al or another transparent conductive oxide (TCO); or a conductive polymer, in particular PEDOT / PSS (poly(3,4-ethylenedioxy-thiophene) poly-(styrenesulfonate)) or PANI (polyaniline).

[0092] In various embodiments, the electrodes arranged on the substrate are translucent to light. "Translucent" is understood as a material that is partially light-transmissive, having a transmittance in the range of 1% to 100% at least in a specific light wavelength range.

[0093] In an embodiment, the optoelectronic component has at least on a substrate:

[0094] i. Two mirrors separated from each other and facing each other, which form an optical microcavity,

[0095] ii. a photoactive layer arranged between the mirror surfaces, the photoactive layer containing at least one compound according to formula (I) and one further compound, wherein the further compound is preferably selected from the group consisting of fullerenes, preferably C 60 or C 70Fullerene, or a fullerene derivative, preferably 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C 61 (PCBM), wherein the energy difference between the HOMO energy of the compound according to formula (I) and the LUMO energy of the further compound is lower than 1.6 eV,

[0096] wherein the optical path length between the mirrors is equivalent to 25 to 75% of the wavelength of the signal to be detected, and

[0097] Among them, the energy equivalent range of the wavelength range of the electromagnetic signal to be detected is

[0098] - the energy difference defined by the HOMO energy of the compound according to formula (I) and the LUMO energy of the further compound, and

[0099] - the energy difference defined by the HOMO energy and the LUMO energy of the compound according to formula (I),

[0100] wherein the photoactive layer is aligned within the optical microcavity at a spatial intensity maximum of the wavelength of the electromagnetic signal to be detected between the mirror surfaces;

[0101] A further aspect of the invention relates to the use of optoelectronic components for the detection of electromagnetic signals in the wavelength range of 780 nm to 10 μm with spatial, temporal and / or spectral resolution and for their further processing.

[0102] For the implementation of the invention, it is also expedient to combine the features of the aforementioned embodiments and claims, in particular to apply the aforementioned embodiments of the compounds according to the invention to the described uses and the described electronic or optoelectronic components.

[0103] The present invention is explained in more detail below with the aid of some exemplary embodiments and related drawings. The exemplary embodiments are intended to illustrate but not to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Figure 1 The results show that the thienyl-substituted bipyran and dithiobipyran are substituted with dimethylformamide (DMF) (c = 10 -5 mol / l).

[0105] Figure 2 The samples containing 2,2',6,6'-tetrathienyl-4,4'-dithiodipyran (reference) (circles) or 2,2',6,6'-tetrakis(2-methylthienyl)-4,4'-dithiodipyran (squares) and C 60Measurement of the external quantum efficiency (EQE) and internal quantum efficiency (IQE) of optoelectronic components. Unfilled symbols represent the IQE in the 425nm to 525nm spectral range (IQE = EQE·Absorbance -1 ). The dashed line represents the average IQE. The solid symbols represent the EQE.

[0106] Figure 3 Shows a) Compound C 60 The CT absorbance curve of the mixture σ CT (Linear and logarithmic scales). b) Oscillator strength f σ , c) Structures of symmetrical thienyl-substituted bipyranes and dithiobipyranes.

[0107] General synthesis processing technology

[0108] Solvents were purified and dried according to standard techniques before use.

[0109] Electrospray ionization mass spectrometry Ionization-Mass Spectrometry, ESI-MS)

[0110] Mass spectrometry was performed with the aid of a Bruker Esquire Ion Trap (ESI / APCI) and a sample concentration of 2 mg / l.

[0111] Nuclear Magnetic Resonance (NMR) spectroscopy

[0112] NMR spectra were measured using a Bruker AC 300, AC-600, or Bruker DRX 500 nuclear magnetic resonance spectrometer in deuterated solvents at 26 to 30°C. 1 H and 13 The shifts of the C resonances are given in ppm relative to the residual signal of the undeuterated solvent. Coupling constants are given in Hz without assigned symbols, with the following abbreviations used for the multiplicities of the individual signals: s: singlet; d: doublet; dd: doublet of a doublet; t: triplet; qua: quartet; qi: quintet; sep: septet; m: multiplet; br.s.: broad signal.

[0113] Ultraviolet-visible (UV-Vis) absorption spectroscopy

[0114] Optical characterization was performed by UV-Vis spectroscopy to determine the optical bandwidth, shape of the absorption band and extinction coefficient. UV-Vis spectra were measured by a Perkin Elmer Lambda 25 UV / VIS spectrophotometer at a scan rate of 600 nm / min.

[0115] Synthesis Procedure of 1,5-di-(2-thienyl)pentane-1,5-dione

[0116] In a 100ml round-bottom flask, 15ml of anhydrous dichloromethane (DCM) was added to 16.0g (120mmol, 2 equivalents) of aluminum chloride under a protective gas atmosphere. A solution of 11.6ml (120mmol, 2.4 equivalents) of thiophene and 6.4ml (50mmol, 1 equivalent) of glutaryl chloride in 15ml of DCM was added dropwise over 10 minutes. During the addition, the color changed from bright orange to dark red. The solution was stirred overnight and the flask was cooled in an ice bath. The reaction was terminated with ice and concentrated hydrochloric acid (2ml). Water was added under stirring until the exothermic reaction with excess aluminum chloride was complete. The mixture was diluted with 50ml of DCM and stirred for 2 hours. The organic phase was extracted with warm DCM, dried over magnesium sulfate and concentrated under vacuum. The crude product was ground and washed with cold ether.

[0117]

[0118] Molecular formula: C 13 H 12 O2S2 (264.03 g / mol)

[0119] Yield: 11.2 g (42.3 mmol, 85%)

[0120] ESI-MS: m / z 265[M] +

[0121] 1 H-NMR (500MHz, CDCl3, ppm): δ=7.73 (dd, J=3.8, 1.1Hz, 1H), 7.61 (dd, J=4.9, 1.1Hz, 1H), 7.10 (dd, J=4.9, 3.8Hz, 1H), 3.04 (t, J=7.0Hz, 2H), 2.19 (qt, J=7.0, 3.5Hz, 1H).

[0122] 13 C-NMR (75MHz, CDCl3, ppm): δ=193.39, 144.81, 134.22, 132.68, 128.78, 38.81, 19.96.

[0123] Synthesis Procedure of 2,6-di-(2-thienyl)pyrylium tetrafluoroborate

[0124] 9.7 ml (76.2 mmol, 10 equivalents) of tetrafluoroboric acid solution (50% (m / m) in water) were added dropwise over 30 minutes to a suspension of 2.0 g (7.6 mmol, 1 equivalent) of 1,5-di-(2-thienyl)pentane-1,5-dione in 50 ml of acetic anhydride, while the temperature was kept below 15° C. by means of an ice bath. After the addition was complete, the mixture was stirred at room temperature for a further 2 h and left at 5° C. overnight. After the addition of 500 ml of hexane / diethyl ether (1:10), a brown precipitate precipitated. The product was obtained by vacuum filtration, washing with diethyl ether and drying under vacuum at room temperature.

[0125]

[0126] Molecular formula: C 13 H9BF4OS2 (332.01 g / mol)

[0127] Yield: 1.59 g (4.8 mmol, 63%)

[0128] ESI-MS: m / z 245 [M-BF4] + , 277[M-BF4+CH3OH] +

[0129] Absorbance (DCM): α max =489nm(ε=30458Lmol -1 cm -1 )

[0130] 1 H-NMR (500 MHz, acetonitrile, ppm): δ = 8.61 (t, J = 8.4 Hz, 1H), 8.28 (dd, J = 4.0, 1.1 Hz, 2H), 8.21 (dd, J = 4.9, 1.1 Hz, 2H), 8.08 (d, J = 8.4 Hz, 2H), 7.44 (dd, J = 4.9, 4.1 Hz, 2H).

[0131] 13 C-NMR (75 MHz, acetonitrile, ppm): δ = 167.00, 155.90, 140.54, 186.98, 188.28, 181.95, 117.71.

[0132] Synthesis Procedure of 2,2',6,6'-Tetrathienyl-4,4'-bipyran

[0133] Under a protective gas atmosphere, 1.2 ml (4.7 mmol, 1 equivalent) of tributylphosphine was added to an orange suspension of 1.56 g (4.7 mmol, 1 equivalent) of 2,6-di-(2-thienyl)pyrylium tetrafluoroborate in 50 ml of dry acetonitrile. The mixture turned yellow and was stirred at room temperature for 2.5 h. 4.0 ml (23.5 mmol, 5 equivalents) of N,N-diisopropylethylamine were subsequently added. The mixture was boiled at 95° C. under reflux under a protective gas atmosphere for 2 h and allowed to stand overnight. After filtering, washing with acetonitrile and drying in air, the product was obtained as a black solid.

[0134]

[0135] Molecular formula: C 26 H 16 O2S4(488.00g / mol)

[0136] Yield: 0.62 g (1.27 mmol, 54%)

[0137] ESI-MS: m / z 488[M] +

[0138] Absorbance (DMF): α max =482nm(ε=29610Lmol -1 cm -1 )

[0139] Melting point: 239°C

[0140] 1 H-NMR (500MHz, CDCl3, ppm): δ=7.74 (dd, J=3.7, 1.1Hz, 1H), 7.65 (dd, J=5.0, 1.1Hz, 1H), 7.21 (dd, J=5.0, 3.7Hz, 1H), 6.95 (s, 1H).

[0141] 13 C-NMR (125.75MHz, CDCl3, ppm): δ=144.90, 136.50, 12.08, 126.42, 124.15, 113.68, 101.85.

[0142] Synthesis of 2,6-dithienylthiopyrylium perchlorate

[0143] In a 250 ml round-bottom flask, 7.80 g (29.5 mmol, 1.0 equivalent) of 1,5-di-(2-thienyl)pentane-1,5-dione, 9.86 g (44.3 mmol, 1.5 equivalents) of phosphorus (V) sulfide, 180 ml of acetic acid and 18.90 g (60 mmol, 6.0 equivalents) of lithium perchlorate were gradually introduced. The mixture was boiled under reflux for 3 h. The color changed from orange to dark red. A green solid was obtained by filtration and washing with hot acetic acid. The filtrate was concentrated under vacuum and a black solid was obtained by adding excess ether and storing at 5 ° C overnight. The crude product was recrystallized in acetic acid to obtain green crystals.

[0144]

[0145] Molecular formula: C 13 H9ClO4S3(359.94g / mol)

[0146] Yield: 3.0 g (8.3 mmol, 28%)

[0147] ESI-MS: m / z 261[M-ClO4] +

[0148] Absorbance (DCM): α max =514nm(ε=31902Lmol -1 cm -1 )

[0149] 1 H-NMR (500 MHz, acetonitrile, ppm): δ = 8.55 (t, J = 8.8 Hz, 1H), 8.43 (d, J = 8.7 Hz, 2H), 8.20-8.04 (m, 4H), 7.42 (dd, J = 4.9, 4.0 Hz, 2H).

[0150] 13 C-NMR (125.75 MHz, acetonitrile, ppm): δ = 162.24, 151.35, 139.07, 137.80, 134.81, 132.50, 130.26.

[0151] Synthesis Procedure of 2,2',6,6'-Tetrathienyl-4,4'-dithiodipyran (Reference)

[0152] Under protective gas, 0.65 ml (2.6 mmol, 1 equivalent) of tributylphosphine was added to a purple suspension of 0.95 g (2.6 mmol, 1 equivalent) of 2,6-dithienylthiopyrylium perchlorate in 50 ml of dry acetonitrile. The mixture turned gray and was stirred at room temperature for 2.5 h. 2.2 ml (13.0 mmol, 5 equivalents) of N,N-diisopropylethylamine were then added. The mixture was boiled at 95° C. under reflux under protective gas for 2 h and allowed to stand overnight. After filtration and recrystallization from DMSO, the product was obtained as a black solid.

[0153]

[0154] Molecular formula: C 26 H 16 S6 (519.96 g / mol)

[0155] Yield: 0.26 g (0.5 mmol, 39%)

[0156] ESI-MS: m / z 520[M] +

[0157] Absorbance (DMF): α max =512nm

[0158] Melting point: 314°C

[0159] 1 H-NMR (500 MHz, pyridine, ppm): δ = 7.52 (dd, J = 5.1, 1.1 Hz, 1H), 7.50 7.46 (m, 1H), 7.40 (s, 1H), 7.13 (dd, J = 5.1, 3.7 Hz, 1H).

[0160] Synthesis Procedure of 1,5-di-(2-(5-methyl)thienyl)pentane-1,5-dione

[0161] In a 100ml round-bottom flask, 15ml of anhydrous dichloromethane (DCM) was added to 16.0g (120mmol, 2 equivalents) of aluminum chloride under a protective gas atmosphere. A solution of 11.6ml (120mmol, 2.4 equivalents) of 2-methylthiophene and 6.4ml (50mmol, 1 equivalent) of glutaryl chloride in 15ml of DCM was added dropwise over 10min. Upon addition, the color changed from bright orange to dark red. The solution was stirred overnight and the flask was cooled in an ice bath. The reaction was terminated with ice and concentrated hydrochloric acid (2ml). Water was added under stirring until the exothermic reaction with excess aluminum chloride was complete. The mixture was diluted with 50ml of DCM and stirred for 2h. The organic phase was extracted with warm DCM, dried over magnesium sulfate and concentrated under vacuum. The crude product was ground and washed with cold ether.

[0162]

[0163] Molecular formula: C 15 H 16 O2S2 (292.06 g / mol)

[0164] Yield: 9.9 g (33.8 mmol, 68%)

[0165] ESI-MS: m / z 293[M] +

[0166] 1 H-NMR (500MHz, CDCl3, ppm): δ=7.53 (d, J=3.7Hz, 1H), 6.76 (m, 1H), 2.94 (t, J=7.0Hz, 2H), 2.51 (d, J=0.7Hz, 3H), 2.13 (p, J=7.0Hz, 1H).

[0167] 13 C-NMR (125,75MHz, CDCl3, ppm): δ=192.47, 149.60, 141.96, 132.64, 126.74, 37.75, 19.72, 15.60.

[0168] Synthesis Procedure of 2,6-bis-(2-(5-methyl)thienyl)pyrylium tetrafluoroborate

[0169] 9.7 ml (76.2 mmol, 10 equivalents) of tetrafluoroboric acid solution (50% (m / m) in water) were added dropwise over 30 minutes to a suspension of 2.2 g (7.6 mmol, 1 equivalent) of 1,5-di-(2-(5-methyl)thienyl)pentane-1,5-dione in 50 ml of acetic anhydride, while the temperature was kept below 15° C. by means of an ice bath. After the addition was complete, the mixture was stirred at room temperature for a further 2 h and left at 5° C. overnight. After the addition of 500 ml of hexane / diethyl ether (1:10), a red precipitate precipitated. The product was obtained by vacuum filtration, washing with diethyl ether and drying under vacuum at room temperature.

[0170]

[0171] Molecular formula: C 15 H 13 BF4OS2 (360.04 g / mol)

[0172] Yield: 1.0 g (2.8 mmol, 37%)

[0173] ESI-MS: m / z 273 [M-BF4] + , 305[M-BF4+CH3OH] +

[0174] Absorbance (DCM): α max =520nm(ε=27691Lmol -1 cm -1 )

[0175] 1 H-NMR (500 MHz, acetonitrile, ppm): δ = 8.45 (t, J = 8.4 Hz, 1H), 8.06 (d, J = 4.0 Hz, 2H), 7.88 (d, J = 8.4 Hz, 2H), 7.13 (dd, J = 4.0, 0.9 Hz, 2H), 2.66 (s, 6H).

[0176] 13 C-NMR (75 MHz, acetonitrile, ppm): δ = 166.03, 157.53, 154.45, 137.45, 131.13, 130.83, 116.23, 16.58.

[0177] Synthesis Procedure of 2,2',6,6'-Tetrakis-(2-methylthienyl)-4,4'-bipyran

[0178] Under a protective gas atmosphere, 1.2 ml (4.7 mmol, 1 equivalent) of tributylphosphine was added to an orange suspension of 1.69 g (4.7 mmol, 1 equivalent) of 2,6-di-(2-(5-methyl)thienyl)pyrylium tetrafluoroborate in 50 ml of dry acetonitrile. The mixture turned yellow and was stirred at room temperature for 2.5 h. 4.0 ml (23.5 mmol, 5 equivalents) of N,N-diisopropylethylamine were subsequently added. The mixture was boiled at 95° C. under reflux under a protective gas atmosphere for 2 h and left overnight. After filtering, washing with acetonitrile and drying in air, the product was obtained as a black solid.

[0179]

[0180] Molecular formula: C 30 H 24 O2S4 (544.07 g / mol)

[0181] Yield: 0.89 g (1.64 mmol, 70%)

[0182] HR-EI-MS: m / z 544.0661[M] +

[0183] Absorbance (DMF): α max =488nm(ε=44663Lmol -1 cm -1 )

[0184] Melting point: 328°C

[0185] 1 H-NMR (600MHz, Benzol, ppm): δ=7.16 (s, 1H), 6.45 (d, J=3.0Hz, 1H), 6.40 (br.s., 1H), 2.11 (br.s., 3H).

[0186] Synthesis of 2,6-bis(5-methylthienyl)thiopyrylium perchlorate

[0187] In a 250 ml round-bottom flask, 5.00 g (17.1 mmol, 1.0 eq) of 1,5-bis-(2-(5-methyl)thienyl)pentane-1,5-dione, 5.72 g (25.7 mmol, 1.5 eq) of phosphorus(V) sulfide, 250 ml of acetic acid, and 10.90 g (102.2 mmol, 6.0 eq) of lithium perchlorate were gradually introduced. The mixture was boiled under reflux for 3 h. The color changed from orange to dark purple. The mixture was filtered hot and allowed to stand for 48 h. The green crystals were washed with diethyl ether and air-dried.

[0188]

[0189] Molecular formula: C 15 H 13 ClO4S3 (387.97 g / mol)

[0190] Yield: 2.16 g (5.6 mmol, 33%)

[0191] ESI-MS: m / z 289[M-ClO4] +

[0192] Absorbance (DCM): α max =552nm(ε=37946Lmol -1 cm -1 )

[0193] 1 H-NMR (500 MHz, acetonitrile, ppm): δ = 3.33 (dd, J = 9.5, 3.1 Hz, 1H), 3.25 ± 3.15 (m, 2H), 7.93 (d, J = 4.0 Hz, 2H), 7.13 (dd, J = 4.0, 1.0 Hz, 2H), 2.65 (s, 6H).

[0194] 13 C-NMR (75 MHz, acetonitrile, ppm): δ = 161.09, 156.02, 150.44, 135.56, 135.27, 131.57, 123.49, 16.76.

[0195] Synthesis of 2,2',6,6'-tetrakis(2-methylthienyl)-4,4'-dithiopyran

[0196] Under protective gas, 0.7 ml (2.8 mmol, 1 equivalent) of tributylphosphine was added to a purple suspension of 1.10 g (2.8 mmol, 1 equivalent) of 2,6-bis(5-methylthienyl)pyrylium sulfonate in 50 ml of dry acetonitrile. The mixture turned gray and was stirred at room temperature for 2.5 h. 2.4 ml (14.0 mmol, 5 equivalents) of N,N-diisopropylethylamine were then added. The mixture was boiled at 95° C. under reflux under protective gas for 2 h and allowed to stand overnight. The product was obtained as a black solid after filtration and recrystallization from DMSO.

[0197]

[0198] Molecular formula: C 30 H 24 S6 (576.02 g / mol)

[0199] Yield: 0.58 g (1.0 mmol, 72%)

[0200] ESI-MS: m / z 576[M] +

[0201] Absorbance (DMF): α max =521nm

[0202] Melting point: 304°C

[0203] 1 H-NMR (500 MHz, pyridine, ppm): δ = 7.35 (m, 1H), 7.29 (d, J = 3.6 Hz, 1H), 6.76 (dd, J = 3.6, 1.1 Hz, 1H), 2.33 (s, 3H).

[0204] Synthesis Procedure of 1,5-di-(2-(5-ethyl)thienyl)pentane-1,5-dione

[0205] In a 100ml round-bottom flask, 15ml of anhydrous dichloromethane (DCM) was added to 16.0g (120mmol, 2 equivalents) of aluminum chloride under a protective gas atmosphere. A solution of 12.7ml (120mmol, 2.4 equivalents) of 2-ethylthiophene and 6.4ml (50mmol, 1 equivalent) of glutaryl chloride in 15ml of DCM was added dropwise over 10 minutes. During the addition, the color changed from bright orange to dark red. The solution was stirred overnight and the flask was cooled in an ice bath. The reaction was terminated with ice and concentrated hydrochloric acid (2ml). Water was added under stirring until the exothermic reaction with excess aluminum chloride was complete. The mixture was diluted with 50ml of DCM and stirred for 2 hours. The organic phase was extracted with warm DCM, dried over magnesium sulfate and concentrated under vacuum. The crude product was ground and recrystallized from ether.

[0206]

[0207] Molecular formula: C 17 H 20 O2S2 (320.09 g / mol)

[0208] Yield: 10.3 g (32.1 mmol, 64%)

[0209] ESI-MS: m / z 321[M] +

[0210] 1 H-NMR (500MHz, CDCl3, ppm): δ=7.55 (d, J=3.8Hz, 1H), 6.79 (dt, J=3.8, 0.9Hz, 1H), 2.95 (t , J=7.0Hz, 2H), 2.85 (qd, J=7.5, 0.6Hz, 2H), 2.14 (p, J=7.0Hz, 1H), 1.30 (t, J=7.5Hz, 3H).

[0211] 13 C-NMR (75MHz, CDCl3, ppm): δ=192.52, 157.16, 141.46, 132.47, 124.90, 37.76, 24.00, 19.74, 15.53.

[0212] Synthesis Procedure of 2,6-bis-(2-(5-ethyl)thienyl)pyrylium tetrafluoroborate

[0213] 9.7 ml (76.2 mmol, 10 equivalents) of tetrafluoroboric acid solution (50% (m / m) in water) were added dropwise over 30 minutes to a suspension of 2.4 g (7.6 mmol, 1 equivalent) of 1,5-di-(2-(5-ethyl)thienyl)pentane-1,5-dione in 50 ml of acetic anhydride, while the temperature was kept below 15° C. by means of an ice bath. After the addition was complete, the mixture was stirred at room temperature for a further 2 h and left at 5° C. overnight. After the addition of 500 ml of hexane / diethyl ether (1:10), a red precipitate precipitated. The product was obtained by vacuum filtration, washing with diethyl ether and drying under vacuum at room temperature.

[0214]

[0215] Molecular formula: C 17 H 17 BF4OS2 (388.07 g / mol)

[0216] Yield: 1.4 g (3.6 mmol, 48%)

[0217] ESI-MS: m / z 301[M-BF4] +

[0218] Absorbance (DCM): α max =524nm(ε=31596Lmol -1 cm -1 )

[0219] 1 H-NMR (500MHz, acetonitrile, ppm): δ=8.45 (t, J=8.4Hz, 1H), 8.11 (d, J=4.1Hz, 2H), 7.89 (d, J=8 .4Hz, 2H), 7.20 (dt, J=4.1, 0.9Hz, 2H), 3.05 (q, J=7.5Hz, 4H), 1.39 (t, J=7.5Hz, 6H).

[0220] 13 C-NMR (75 MHz, acetonitrile, ppm): δ = 165.95, 164.53, 154.10, 137.05, 130.22, 129.13, 115.99, 24.79, 15.56.

[0221] Synthesis Procedure of 2,2',6,6'-Tetra-(2-ethylthienyl)-4,4'-bipyran

[0222] Under a protective gas atmosphere, 1.3 ml (5.2 mmol, 1 equivalent) of tributylphosphine was added to an orange suspension of 2.0 g (5.2 mmol, 1 equivalent) of 2,6-di-(2-(5-ethyl)thienyl)pyrylium tetrafluoroborate in 60 ml of dry acetonitrile. The mixture turned yellow and was stirred at room temperature for 2.5 h. 4.4 ml (26 mmol, 5 equivalents) of N,N-diisopropylethylamine were subsequently added. The mixture was boiled at 95° C. under reflux under a protective gas atmosphere for 2 h and left overnight. After filtering, washing with acetonitrile and drying in air, the product was obtained as a black solid.

[0223]

[0224] Molecular formula: C 34 H 32 O2S4 (600.13 g / mol)

[0225] Yield: 1.0 g (1.67 mmol, 64%)

[0226] HR-EI-MS: m / z 600.1288[M] +

[0227] Absorbance (DMF): α max =488nm(ε=51749Lmol -1 cm -1 )

[0228] Melting point: 221°C

[0229] 1 H-NMR (500MHz, Benzol, ppm): δ=7.16 (s, 1H), 6.52 (d, J=3.5Hz, 1H), 6.44 (br.s., 1H), 2.53 (br.s., 2H), 1.07 (t, J=7.6HZ, 3H).

[0230] Synthesis of 2,6-bis(5-ethylthienyl)thiopyrylium perchlorate

[0231] In a 250 ml round-bottom flask, 4.00 g (12.6 mmol, 1.0 eq) of 1,5-di-(2-(5-ethyl)thienyl)pentane-1,5-dione, 4.21 g (18.9 mmol, 1.5 eq) of phosphorus (V) sulfide, 250 ml of acetic acid, and 8.07 g (75.6 mmol, 6.0 eq) of lithium perchlorate were gradually introduced. The mixture was boiled under reflux for 3 h. The color changed from orange to dark purple. The mixture was filtered hot and allowed to stand for 48 h.

[0232] The green crystals were washed with ether and dried in air.

[0233]

[0234] Molecular formula: C 17 H 17 ClO4S3 (416.00 g / mol)

[0235] Yield: 2.23 g (5.4 mmol, 43%)

[0236] ESI-MS: m / z 317 [M-ClO4] +

[0237] Absorbance (DCM): α max =554nm(ε=39270Lmol -1 cm -1 )

[0238] 1 H-NMR (300MHz, acetonitrile, ppm): δ=8.39 (dd, J=9.6, 3.0Hz, 1H), 8.26-8.16 (m, 2H), 7.95 (d, J= 4.0Hz, 2H), 7.18 (dt, J=4.0, 0.9Hz, 2H), 3.01 (q, J=7.5Hz, 4H), 1.37 (t, J=7.5Hz, 6H).

[0239] 13 C-NMR (125,75MHz, CDCl3, ppm): δ=161.92, 159.34, 149.72, 134.38, 133.70, 128.64, 126.94, 24.42, 15.28.

[0240] Synthesis of 2,2',6,6'-tetrakis(2-ethylthienyl)-4,4'-dithiopyran

[0241] Under a protective gas atmosphere, 0.6 ml (2.4 mmol, 1 equivalent) of tributylphosphine was added to a purple suspension of 1.0 g (2.4 mmol, 1 equivalent) of 2,6-bis(5-ethylthienyl)pyrylium sulfonate in 50 ml of dry acetonitrile. The mixture turned gray and was stirred at room temperature for 2.5 h. 2.1 ml (12.0 mmol, 5 equivalents) of N,N-diisopropylethylamine were then added. The mixture was boiled at 95° C. under reflux under a protective gas atmosphere for 2 h and allowed to stand overnight. After filtration, washing with acetonitrile and drying in air, the product was obtained in the form of black crystals.

[0242]

[0243] Molecular formula: C 34 H 32 S6 (632.08 g / mol)

[0244] Yield: 0.46 g (0.73 mmol, 61%)

[0245] ESI-MS: m / z 632[M] +

[0246] Absorbance (DMF): α max =521nm(ε=72122Lmol -1 cm -1 )

[0247] Melting point: 253°C

[0248] 1 H-NMR (500 MHz, pyridine, ppm): δ = 7.41 (s, 1H), 7.34 (d, J = 3.6 Hz, 1H), 6.80 (d, J = 3.6 Hz, 1H), 2.70 (q, J = 7.5 Hz, 2H), 1.17 (t, J = 7.5 Hz, 3H).

[0249] 13 C-NMR (125,75MHz, Benzol, ppm): δ=147.99, 139.99, 127.12, 125.02, 124.74, 124.42, 119.13, 24.16, 16.34.

[0250] Figure 1 The UV-Vis absorption spectra of thienyl-substituted bipyrans and dithiobipyrans in dimethylformamide (DMF) are shown. Each curve is normalized to the strongest π-π* transition. In the case of thienyl-substituted bipyrans, the absorption band splits into two peaks and has two low-intensity red-shifted shoulders. Compared to the equivalent thienyl-substituted bipyrans, the absorption band of thienyl-substituted dithiobipyrans has a red shift of about 100 nm, λ max Furthermore, the methyl-substituted or ethyl-substituted thienyl compounds have a red shift compared to the unsubstituted thienyl compounds.

[0251] 1,5-Bis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl])pentane-1,5- Synthesis protocol for diketones

[0252] Suspend 2.33 g of AlCl₃ in 20 ml of dry DCM with vigorous stirring and ice-cooling. Slowly add dropwise a solution of 2.72 g of 5-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl, 1.4 g of glutaryl chloride, and 20 ml of DCM under ice-cooling. Stir at room temperature for an additional 24 h.

[0253]

[0254] Molecular formula: C 19 H 20 O6S2 (408.48 g / mol)

[0255] Yield: 2.7 g (80%)

[0256] ESI-MS: m / z 409.1[MH] +

[0257] 2,6-Bis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl])-thiopyranium Synthesis protocol for perchlorate

[0258] 2.5 g of 1,5-bis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl])pentane-1,5-dione, 2.1 g of P2S 10 The mixture was heated under reflux for 3 h with 3.9 g of LiClO4 in 80 ml of glacial acetic acid. After cooling and standing overnight, the purple solid was filtered off with suction and washed with ether.

[0259]

[0260] Molecular formula: C 19 H 17 ClO8S3 (504.98 g / mol)

[0261] Yield: 1.92 g (77%)

[0262] ESI-MS: m / z 405.1[M-ClO4] +

[0263] 2,2',6,6'-tetrakis(7-methyl-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-4, 4'-dithiopyranylene

[0264] Under N2 sparge, 1.5 g of the corresponding thiopyrylium salt was dissolved in 40 ml of acetonitrile and 0.73 ml of PBu3 was added. The mixture was stirred at room temperature for 2 h, 1.5 ml of Hünig's base was added and heated under reflux for 2 h. After cooling, crystals formed, which were filtered with suction and washed with a suitable solvent.

[0265]

[0266] Molecular formula: C 38 H 32 O8S6 (809.03 g / mol)

[0267] Yield: 0.88 g (73%)

[0268] ESI-MS: m / z 808.1[M] +

[0269] General Procedure for the Synthesis of Diselenide-Bis(pyranylene)

[0270] Diselenopyrans can be obtained, for example, from selenopyrone via selenopyronethione (Detty et al., 1985). 10 mmol of the corresponding selenopyronethione and 3 g of copper powder were stirred in 30 ml of toluene and heated to reflux under inert gas for 16 h. The reaction mixture was subjected to appropriate post-treatment and recrystallized from acetonitrile.

[0271]

[0272] General Procedure for the Synthesis of Asymmetric Bipyrans

[0273] Asymmetric bipyrylidenes can be synthesized analogously to the symmetrical compounds via phosphonium salts in a two-step reaction according to Reynolds and Chen (Reynolds and Chen 1980). Thio(seleno)pyrylium salts can also be phosphonated and then reacted with pyrylium salts.

[0274] A solution of 10 mmol of pyrylium salt in 25 ml of acetonitrile was stirred at room temperature for 2 h until the intense yellow color disappeared. The white precipitate was filtered off with suction and washed with acetonitrile.

[0275]

[0276] In two steps, the suspension of the corresponding previously shown phosphonium salt of 2mmol in 35ml THF was cooled to-78 ℃ under protective gas under stirring. Slowly add 0.9ml of 2.5M n-BuLi and stir other 5min. Add 2mmol of desired thio or seleno-pyrylium salt subsequently and stir 1h at-78 ℃, then add 5ml triethylamine. The reaction mixture is slowly warming up to room temperature overnight and with purification by chromatography. In this case, achieve good to very good yield.

[0277]

[0278] Trifluoromethylation method

[0279] Negishi et al. describe a trifluoromethylation method for preparing compounds according to the invention having perfluoroalkyl groups (Negishi et al., 2016).

[0280] Electrochemical characterization

[0281] Cyclic Voltammetry (CV)

[0282] In order to measure the oxidation and reduction potentials and further determine the HOMO / LUMO energy levels, cyclic voltammetry was performed using a potentiostat (Methrom, μ-Autolab) and a 3-electrode cell configuration. Tetrabutylammonium hexafluorophosphate (0.1 M) in dry dimethylformamide (DMF) or dimethyl sulfoxide (DMSO) was used as the electrolyte, a glass-platinum electrode was used as the working electrode, a platinum wire was used as the counter electrode, and Ag / AgCl was used as the pseudo-reference electrode. Ferrocene / ferrocenium was used as the internal standard to scale the measurement potential. All solvents were deoxygenated with nitrogen before measurement. The measurements were performed in the range of -1 V to 1 V with scan rates of 50 mV / s and 100 mV / s. The samples were measured at a concentration of 1 mM / l.

[0283] Differential scanning calorimetry (DSC)

[0284] Thermal characterization was carried out by means of dynamic differential calorimetry (DSC) to determine phase transitions, melting temperatures and decomposition temperatures.DSC was performed under a nitrogen atmosphere with the aid of a Mettler-Toledo DSC 1 Star and a scanning rate of 5 K / min.

[0285] sublimation

[0286] The compound was crystallized two or three times to increase the purity. Sublimation was carried out using a 3-zone gradient furnace from VEB Hochvakuum Dresden.

[0287] Preparation of optoelectronic components

[0288] Optoelectronic components were produced, for example, by thermal evaporation under ultrahigh vacuum (8 to 10 mbar) on glass substrates with prestructured ITO contacts (ThinFilm Devices, USA). On it was deposited a layer of 4,7-diphenyl-1,10-phenanthroline (BPhen): Cs, C60, 2,2',6,6'-tetrathienyl-4,4'-dithiodipyran or 2,2',6,6'-tetrakis(2-methylthienyl)-4,4'-dithiodipyran: C60 (5% (m / m) mixture in C60), N4,N4'-bis(9,9-dimethyl-9H-265-fluoren-2-yl)-N4,N4'-diphenylbiphenyl-4,4'-diamine (BF-DPB): F6-TCNNQ, 2,2'-(perfluoronaphthalene-2,6-diylidene) dimalononitrile (F6-TCNNQ) and Al. The assembly was characterized by a geometric overlap of 6.44 m between the upper and lower contacts. 2 The organic area is bonded to the small glass substrate.

[0289] Sensitive external quantum efficiency (EQE) measurements

[0290] To measure the external quantum efficiency using a monochromatic light source, a current was generated in an organic solar cell (OSC) under short-circuit conditions. The generated current was preamplified and analyzed using a lock-in amplifier (Signal Recovery 7280 DSP).

[0291] Figure 2 Shown are 2,2',6,6'-tetrathienyl-4,4'-dithiodipyran (reference) (circles) or 2,2',6,6'-tetrakis(2-methylthienyl)-4,4'-dithiodipyran (squares) and C 60 The external quantum efficiency (EQE) and internal quantum efficiency (IQE) of the photovoltaic components of the mixture are measured. The IQE (IQE = EQE·absorbance) is calculated in the 425nm to 525nm spectral range. -1 ) and assuming that the IQE is independent of the excitation wavelength to calculate the average IQE.

[0292] Using the IQE in a 50 nm thin layer and the density of donor molecules, the EQE spectrum is converted to an absorption curve σ CT ( Figure 3 The methylated compounds show a red-shifted CT absorbance compared to the equivalent non-methylated compounds. The introduction of sulfur into the subpyran nucleus shifts the peak σ CT and f σ Increased to twice.

[0293] Cited non-patent literature

[0294] Bolag A,Mamada M,Nishida J,Yamashita Y(2009)Field-Effect TransistorsBased on Tetraphenyldipyranylidenes and the Sulfur Analogues.Chem.Mater.21,4350-4352.

[0295] Detty MR,Hassett JW,Murray BJ,Reynolds GA(1985)Δ 4,4 -4-Chalcogenpyranyl-4H-Chalcogenapyrans.Tetrahedron 41,4853-4859.

[0296] Fabre C, Fugnitto R, Strzelecka H (1976) On the synthesis of dipyranylidènes. Comptes rendus des séances de l'Académie des Sciences. Series C, Scienceschimiques 282(3), 175-177.

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[0298] Negishi K, Aikawa K, Mikami K(2016) Cyclic-Protected Hexafluoroacetoneas an Air-Stable Liquid Reagent for Trifluoromethylations.European Journal ofOrganic Chemistry 23,4099-4104.

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Claims

1. Compounds according to formula (I) (I)， in, X 1 and X 2 are each independently selected from oxygen, sulfur and selenium, R 1 and R 2 Each independently selected from 、 、 、 、 ， Among them, R 3 Selected from C1 to C20 alkyl groups and cycloalkyl groups, C1 to C20 perfluoroalkyl groups, C1 to C20 aryl groups and heteroaryl groups, C1 to C20 alkoxy groups and thioalkoxy groups, and primary, secondary and tertiary C1 to C20 alkylamino groups.

2. The compound according to claim 1, characterized in that R 3 is selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, pentafluoroisopropyl, nonafluorobutyl, nonafluoro-tert-butyl, nonafluoroisobutyl, 2,2,2-trifluoroethyl, 2,2,3,3,3-pentafluoropropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, 2,2,3,3, 4,4,5,5,6,6,6-undecafluorohexyl, phenyl, benzyl, diphenyl, naphthyl, anthracenyl, phenanthrenyl, pyridyl, furyl, thienyl, thiazolyl, oxazolyl, imidazolyl, pyrimidinyl, thiazinyl, methoxy, ethoxy, propoxy, butoxy, pentyloxy, thiomethoxy, thioethoxy, thiopropoxy, thioisopropoxy, thiobutoxy, thioisobutoxy, t-butoxy, thiohexyloxy, thioisohexyloxy, amino, methylamino, butylamino, tolylamino, dimethylamino, diethylamino, methylphenylamino, methyltolylamino, pyrrolidine, piperidine, morpholine, thiomorpholine, and xylidine.

3. The compound according to claim 1 or 2, characterized in that R 1 With R 2 same.

4. The compound according to claim 1 or 2, characterized in that X 1 and X 2 are each independently selected from sulfur and selenium.

5. The compound according to claim 1 or 2, characterized in that X 1 With X 2 same.

6. The compound according to claim 1 or 2, characterized in that X 1 and X 2 It is oxygen and sulfur, oxygen and selenium, or sulfur and selenium.

7. Use of at least one compound according to formula (I) as a light absorber or infrared absorber, (I)， in X 1 and X 2 are each independently selected from oxygen, sulfur and selenium, R 1 and R 2 Each independently selected from 、 、 、 、 ， in, R 3 Selected from C1 to C20 alkyl groups and cycloalkyl groups, C1 to C20 perfluoroalkyl groups, C1 to C20 aryl groups and heteroaryl groups, C1 to C20 alkoxy groups and thioalkoxy groups, and primary, secondary and tertiary C1 to C20 alkylamino groups.

8. The use according to claim 7, wherein the composition is used in electronic or optoelectronic components.

9. Use according to claim 7 or 8 as donor absorber material in organic solar cells (OSCs), as hole transport material (HTM) in Grätzel cells, in organic integrated circuits (O-ICs), in organic field effect transistors (OFETs), in organic thin film transistors (O-TFTs), in organic light emitting diodes (OLEDs), in photodetectors or in IR sensors.

10. The use according to claim 9 in an infrared (IR) charge transfer (CT) absorption sensor.

11. An electronic or optoelectronic component comprising at least one compound according to formula (I), (I)， in X 1 and X 2 are each independently selected from oxygen, sulfur and selenium, R 1 and R 2 Each independently selected from 、 、 、 、 ， in, R 3 Selected from C1 to C20 alkyl groups and cycloalkyl groups, C1 to C20 perfluoroalkyl groups, C1 to C20 aryl groups and heteroaryl groups, C1 to C20 alkoxy groups and thioalkoxy groups, and primary, secondary and tertiary C1 to C20 alkylamino groups. 12 . The electronic or optoelectronic component according to claim 11 , comprising at least one further compound which is an electron acceptor compound.

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