Fullerene functionalized vinyl polymer and preparation method thereof

Abstract

Fullerene-functionalized vinyl polymers of general formula (I): wherein:-x is a fraction from 0 to 0.89, preferably from 0 to 0.6; -y is a fraction from 0.01 to 0.9, preferably from 0.02 to 0.7; -z is a fraction from 0.1 to 0.99, preferably from 0.05 to 0.8; with the proviso that the sum of x + y + z equals 1; -p is an integer from 10 to 10000, preferably from 20 to 5000; -w is an integer from 50 to 250, preferably from 60 to 90, more preferably from 60, 70, 84; -n is an integer from 1 to 12, preferably from 2 to 6; -R represents a hydrogen atom; or a linear or branched, saturated or unsaturated alkyl group, optionally containing heteroatoms, optionally substituted aryl group, optionally substituted heteroaryl group, optionally substituted cycloalkyl group, optionally substituted heterocyclic group, selected from C1-C20, preferably C1-C10, linear or branched, saturated or unsaturated alkyl groups, optionally containing heteroatoms, optionally substituted aryl group, optionally substituted heteroaryl group, optionally substituted cycloalkyl group, optionally substituted heterocyclic group; and preferably hydrogen. Said fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used as organic photovoltaic devices (or solar devices) (e.g., binary, ternary, quaternary organic photovoltaic cells (or solar cells), organic photovoltaic modules (or solar modules) with a simple or "tandem" structure) on rigid or flexible supports and an electron acceptor compound. In addition, the fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used in perovskite-based photovoltaic cells (or solar cells) in electron transport layers (ETL). In addition, the fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used for producing organic thin film transistors (OTFT) or organic field effect transistors (OFET). # imgabs0 #

Description

[0001] manual

[0002] The present invention relates to fullerene functionalized vinyl polymers.

[0003] More specifically, the present invention relates to fullerene functionalized vinyl polymers having the specific general formula (I) reported below.

[0004] The fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used as electron acceptor compounds in organic photovoltaic devices (or solar devices) on rigid or flexible supports (e.g., binary, ternary, quaternary organic photovoltaic cells (or solar cells), organic photovoltaic modules (or solar modules) with simple or "tandem" structures). In addition, the fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used in perovskite-based photovoltaic cells (or solar cells) in electron transport layers (ETLs). In addition, the fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used in the production of organic thin film transistors (OTFTs) or organic field effect transistors (OFETs).

[0005] Another subject of the present invention is a process for preparing the fullerene-functionalized vinyl polymers of the general formula (I).

[0006] The present invention also relates to an organic photovoltaic device (or solar device) on a rigid support or a flexible support (e.g., an organic binary, ternary, quaternary solar cell, an organic photovoltaic module (or solar module) having a simple or "tandem" structure), which comprises at least one fullerene-functionalized vinyl polymer having a specific general formula (I).

[0007] The present invention also relates to perovskite-based photovoltaic cells (or solar cells), wherein the electron transport layer (ETL) comprises at least one fullerene-functionalized vinyl polymer having the specific general formula (I).

[0008] The present invention also relates to an organic thin film transistor (OTFT) or an organic field effect transistor (OFET) comprising at least one fullerene-functionalized vinyl polymer having the specific general formula (I).

[0009] In the simplest mode of operation, an organic photovoltaic cell (or solar cell) is manufactured by introducing a thin photosensitive layer (about 100 nanometers) of a mixture of an electron acceptor compound and an electron donor compound between two electrodes, usually consisting of indium tin oxide (ITO) (anode) and aluminum (Al) (cathode), a structure known as "bulk heterojunction". In general, to manufacture a layer of this type, a solution of the two compounds is prepared, from which subsequently a photoactive film is formed on the anode [indium tin oxide (ITO)], using a suitable deposition technique (such as "spin coating", "spray coating", "inkjet printing", etc.). Finally, a counter electrode [i.e. an aluminum cathode (Al)] is deposited on the dried film. Optionally, other additional layers can be introduced between the electrodes and the photoactive film, these layers being able to perform specific functions of an electrical, optical or mechanical nature.

[0010] Typically, in order to facilitate the passage of electron gaps (or holes) to the anode [indium tin oxide (ITO)] while blocking the transport of electrons, thereby improving the charge collection of the electrode and suppressing recombination phenomena, before starting to produce the photoactive film from a mixture of acceptor compounds and donor compounds as described above, a film is deposited starting from an aqueous suspension of PEDOT:PSS [poly(3,4-ethylenedioxythiophene) polystyrene sulfonate] using a suitable deposition technique (e.g. "spin coating", "spray coating", "inkjet printing", etc.).

[0011] In most cases, the electron acceptor compound is selected from C 60 , C 70 Fullerene derivatives, such as [6,6]-phenyl-C 61 -Butyric acid methyl ester (PC61BM), (6,6)-phenyl-C 71 -Butyric acid methyl ester (PC71BM). However, the fullerene derivatives show poor solubility in solvents generally used to construct photovoltaic cells (or solar cells), and show a certain tendency to separate in the aforementioned photoactive layer.

[0012] One way to overcome the above-mentioned disadvantages is to incorporate C60 fullerene or C70 fullerene into the polymer structure, as reported in, for example, Giacalone F. et al., "Chemical Reviews" (2006), Vol. 106, No. 12, pp. 5136-5190; Giacalone F. et al., "Advanced Materials" (2010), Vol. 22, pp. 4220-4248.

[0013] Among the various attempts to introduce fullerenes into polymer structures, the use of acrylates and methacrylates as basic macromolecules must be mentioned. The synthetic strategies for the preparation of fullerene-containing (meth)acrylic polymers are in such an advanced state that a range of even highly complex structures can be synthesized by the most diverse polymerization techniques: from conventional free radical polymerization to the more complex atom transfer radical polymerization (ATRP). Thus, it is possible to obtain (meth)acrylic copolymers containing fullerenes of the random type, or (meth)acrylic copolymers containing fullerenes of the block type, which have high or low molecular weights and different polydispersity indices.

[0014] The class of (meth)acrylic acid copolymers containing side chain fullerenes is the most studied class. However, the most direct strategy (i.e., the synthesis of fullerene-functionalized (meth)acrylic acid monomers and their subsequent copolymerization by a free radical route) does not produce the desired polymers, as reported by, for example, Mehrotra S. et al., "Chemical Communications" (1997), pp. 463-464; Kirkwood K. et al., "Journal of Polymer Science Part A: Polymer Chemistry" (1997), Vol. 35, No. 15, pp. 3323-3325. The authors report that, in fact, during the polymerization, C 60 Fullerenes not only retard the polymerization process but also undergo multiple and random addition of free radical chains, resulting in complex polymer mixtures which cannot be regenerated and are even partially crosslinked, which makes the resulting polymers insoluble and therefore unsuitable for the purposes of the present invention.

[0015] C 60Other examples of fullerene functionalized poly(alkyl)methacrylates and poly(hydroxyalkyl)methacrylates are reported by Zheng J. et al., Polymer Bulletin (1997), Vol. 39, pp. 79-84; Lu ZH et al., Polymer Bulletin (1997), Vol. 39, pp. 661-667; Huang HL et al., Langmuir (2003), Vol. 19, pp. 5332-5335; Goh HW et al., Journal of Polymer Science Part A: Polymer Chemistry (2002), Vol. 40, No. 8, pp. 1157-1166. The authors report the synthesis of copolymers containing different amounts of alkyl methacrylates (e.g., methyl methacrylate, ethyl methacrylate, butyl methacrylate or hydroxyalkyl methacrylates such as 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate or 6-hydroxyhexyl methacrylate). After the above methacrylate copolymer is prepared, the hydroxyl group is converted to an azide in two steps to give an azide polymer which can react with fullerene to produce the desired C 60 Functionalized methacrylate copolymers, C 60 The fullerene content is 0.6 wt % to 7.4 wt %. C derived from alkyl methacrylate 60 Fullerene-functionalized methacrylate copolymers are soluble in tetrahydrofuran (THF), chlorobenzene or chloroform, whereas those derived from hydroxyalkyl methacrylates are 60 The fullerene functionalized methacrylate copolymers are soluble in dimethylformamide (DMF) or methanol.

[0016] However, it should be noted that a disadvantage of using the above-mentioned azide polymers is that unreacted azide groups subsequently give rise to crosslinking processes, resulting in materials that are unstable over time and cannot be processed, and therefore cannot be used for the purposes of the present invention.

[0017] Sato H. et al., "Polymer Bullettin" (2015), Vol. 72, No. 11, pp. 904-909, reported the preparation of two different fullerene-containing methacrylate monomers by reaction of fullerenes with 4-azidobenzoyloxyethyl methacrylate or 4-azidobenzoyloxyethyl methacrylate. Interestingly, it was observed that subsequent anionic copolymerization experiments (with Grignard reagents) allowed the obtaining of monomers with low weight-average molecular weight (M w ) but contains up to 10.5 wt% C 60The free radical polymerization of fullerene in the presence of α,α'-azobisisobutyronitrile (AIBN) as a free radical initiator did not occur, which further confirmed that C 60 The acrylic monomers cannot be free radical polymerized.

[0018] Ladelta V. et al., "Polymer Journal" (1998), Vol. 30, pp. 1265-1280 reported that a high C 60 Fullerene content (i.e. up to 41.4% by weight) of polymethyl methacrylate, which is obtained by reacting a copolymer containing an azide with C 60 The copolymer containing azide is obtained by the reaction of fullerene in chlorobenzene. The copolymer is derived from a random copolymer of 6-chlorohexyl methacrylate and methyl methacrylate, which is soluble in common organic solvents such as chloroform (CHCl3), tetrahydrofuran (THF) and toluene. Size exclusion chromatography (SEC) shows that the polymethyl methacrylate forms intramolecular and intermolecular aggregation in chloroform (CHCl3), which may be due to the C 60 The strong interactions between the fullerene side groups, however, do not form these aggregates in tetrahydrofuran.

[0019] Tollan CM et al., "New Journal of Chemistry" (2008), Vol. 32, pp. 1373-1378 reported a method for synthesizing a C 60 A method for preparing acrylic polymers of fullerenes, the method first comprising synthesizing a monosubstituted C 60 Fullerene (i.e. monofullerene pyrrolidine) was then reacted with an acryloyl chloride / methyl acrylate copolymer. The amine groups of the monofullerene pyrrolidine reacted with the acyl chloride groups of the copolymer to form an amide bond. The method allowed the production of a 44 wt.% C 60 Acrylic polymers of fullerenes. However, as the authors point out, the presence of acyl chloride groups in the final polymers due to the incomplete substitution of the fullerene pyrrolidine reagent makes these materials less stable over time due to their high reactivity with moisture in the air. This drawback leads to a gradual crosslinking of the material, making it insoluble and therefore unsuitable for the purposes of the present invention, as the authors emphasize that for the polymer with the highest fullerene content (P4), it is already insoluble as soon as it is prepared.

[0020] Li J. et al., Journal of Materials Chemistry (2009), Vol. 19, pp. 5416-5423 reported that 60 Fullerenes (measured by UV-vis, with an average of up to 78 C per chain) 60To this end, pure C 60 Subsequently, methyl methacrylate and 6-azido-hexyl methacrylate are randomly copolymerized by RAFT polymerization ("reversible addition fragmentation chain transfer polymerization") to obtain a copolymer, which is reacted with the monoalkyne-functionalized fullerene by a copper-catalyzed "click" reaction to obtain the aforementioned polymethacrylate. 60 Fullerene polymethacrylates show interchain “self-aggregation” behavior both in solution and in silicon, which is strongly dependent on the presence of C 60 The amount of fullerenes.

[0021] Biglova YN et al., "Russian Journal of Physical Chemistry B" (2017), Vol. 11, No. 2, pp. 324-329 reported the copolymerization and homopolymerization of acrylate-containing fullerenes with vinyl monomers. The fullerene-containing copolymers are said to be easily soluble in common organic solvents, while the fullerene-containing homopolymers cannot be characterized due to their high degree of crosslinking.

[0022] J. et al., “Journal of Applied Polymer Science” (2018), Vol. 135, No. 10, 45916 reported a self-healing polymeric material composed of poly(lauryl methacrylate) having an anthracene unit in the side chain, C 60 Fullerene and [6,6]-phenyl-C 61 -Butyric acid methyl ester (PC61BM) is covalently but reversibly bonded to the anthracene unit. 60 The bonds formed between fullerenes by cycloaddition [4+2] are reversible and break and reform at 40° C.-60° C. The use of differently substituted anthracene monomers allows tuning of the reactivity and resulting mechanical properties.

[0023] However, although fullerene derivatives known in the art have excellent chemical and physical properties for their use in organic photovoltaic devices (or solar devices), they may also have various technical challenges during the preparation of the photovoltaic devices (or solar devices) or after their use.

[0024] As mentioned above, a major disadvantage is their low solubility in non-toxic solvents and higher solubility in toxic solvents, such as halogenated solvents or carbon disulfide (CS2). In addition, in order to obtain good results in the performance of photovoltaic devices (or solar devices), a large amount of fullerene derivatives must be dispersed in the photoactive layer.

[0025] Furthermore, due to the large surface area of ​​π-π, fullerene derivatives have a tendency to segregate within the photoactive layer even in the solid state, resulting in a drastic decrease in the efficiency of photovoltaic devices (or solar devices) because the formation of crystallites of fullerene derivatives limits the photophysical processes under their operation.

[0026] Furthermore, the methods for preparing fullerene derivatives are usually complicated multi-step processes that are not suitable for industrial processes. Furthermore, the methods usually use halogenated solvents, which are toxic as mentioned above and are therefore undesirable for industrial processes.

[0027] The Applicant therefore solved the problem of finding new fullerene derivatives and processes for their preparation which are able to overcome the above-mentioned disadvantages.

[0028] The Applicant has now discovered fullerene-functionalized vinyl polymers of the specific general formula (I) reported below and processes for their preparation which overcome the aforementioned disadvantages.

[0029] The fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used as electron acceptor compounds in organic photovoltaic devices (or solar devices) on rigid or flexible supports (selected from, for example, binary, ternary, quaternary organic photovoltaic cells (or solar cells), organic photovoltaic modules (or solar modules) with simple or "tandem" structures). In addition, the fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used in perovskite-based photovoltaic cells (or solar cells) in electron transport layers (ETLs). In addition, the fullerene-functionalized vinyl polymers of general formula (I) can be advantageously used in the production of organic thin film transistors (OTFTs) or organic field effect transistors (OFETs).

[0030] Furthermore, the fullerene functionalized vinyl polymers of formula (I) have good solubility, which ensures that the synthesis process does not produce cross-linked materials. In particular, the fullerene functionalized vinyl polymers of formula (I) have good solubility (i.e., solubility of 30 mg / ml-40 mg / ml) in tetrahydrofuran (THF), methyltetrahydrofuran (Me-THF), dimethyl sulfoxide (DMSO), dioxane (i.e., in solvents that are considered to be environmentally "green"), in addition to typical solubility in halogenated solvents (e.g., chloroform, chlorobenzene and dichlorobenzene). In this regard, it should be noted that the vast majority of fullerene derivatives and C 60 Fullerenes exhibit almost zero solubility in this type of solvents [i.e., tetrahydrofuran (THF), methyltetrahydrofuran (Me-THF), dimethyl sulfoxide (DMSO), dioxane], and therefore fullerene-functionalized vinyl polymers having the general formula (I) can be used in photovoltaic devices or conventionally by reacting with conventionally deposited C60 or C 70 The layers can be deposited from solutions in chlorobenzene or xylene in the same manner as fullerene derivatives, or in an unconventional manner, i.e. from solutions in solvents such as tetrahydrofuran (THF), methyltetrahydrofuran (Me-THF), dimethyl sulfoxide (DMSO), dioxane, enabling, for example, co-deposition with perovskite precursors such as lead iodide (PbI2) and methylammonium iodide (MeNH3I).

[0031] Furthermore, the fullerene-functionalized vinyl polymer of formula (I) can be obtained in the presence of a non-halogenated solvent by a one-step process. In addition, it should be noted that the process allows obtaining fullerene-functionalized vinyl polymers of formula (I) containing varying amounts of fullerene and hydroxyl (-OH) groups, which are therefore capable of producing layers that are compatible with both the hydrophobic and hydrophilic layers of organic photovoltaic devices (or solar devices) or perovskite-based photovoltaic cells (or solar cells).

[0032] The subject of the present invention is therefore fullerene-functionalized vinyl polymers of the general formula (I):

[0033]

[0034] in:

[0035] - x is a fraction from 0 to 0.89, preferably from 0 to 0.6;

[0036] -y is a fraction ranging from 0.01 to 0.9, preferably from 0.02 to 0.7;

[0037] - z is a fraction from 0.1 to 0.99, preferably from 0.05 to 0.8;

[0038] -The premise is that the sum of x+y+z is equal to 1;

[0039] - p is an integer from 10 to 10000, preferably from 20 to 5000;

[0040] -w is an integer from 50 to 250, preferably from 60 to 90, more preferably 60, 70, 84;

[0041] - n is an integer from 1 to 12, preferably from 2 to 6;

[0042] -R represents a hydrogen atom; or is selected from C1-C 20 , preferably C1-C 10 The straight-chain or branched, saturated or unsaturated alkyl group which may contain heteroatoms, the aryl group which may be substituted, the heteroaryl group which may be substituted, the cycloalkyl group which may be substituted, the heterocyclyl group which may be substituted; preferably, hydrogen.

[0043] For the purposes of the present description and the following claims, definitions of numerical ranges always include the extreme values, unless otherwise indicated.

[0044] For the purposes of this specification and the following claims, the term "comprising" also encompasses the terms "which consists essentially of" or "which consists of.

[0045] For the purposes of this specification and the following claims, the term “C1-C 20 "Alkyl" refers to a straight chain or branched, saturated or unsaturated alkyl group having 1 to 20 carbon atoms. 20 Specific examples of the alkyl group are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, ethylhexyl, hexyl, heptyl, n-octyl, nonyl, decyl, dodecyl, 2-octyldodecyl, 2-ethyldodecyl, 2-butyloctyl, 2-hexyldecyl.

[0046] For the purposes of this specification and the following claims, the term "C1-C1 optionally containing heteroatoms" 20 "Alkyl" refers to a straight or branched, saturated or unsaturated alkyl group having 1 to 20 carbon atoms, wherein at least one hydrogen atom is substituted by a heteroatom selected from the group consisting of halogen, for example, fluorine, chlorine, bromine, preferably fluorine; nitrogen; sulfur; oxygen. The C1-C 20 Specific examples of the alkyl group are fluoromethyl, difluoromethyl, trifluoromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 2,2,2-trichloroethyl, 2,2,3,3-tetrafluoropropyl, 2,2,3,3,3-pentafluoropropyl, perfluoropentyl, perfluorooctyl, perfluorodecyl, ethyl-2-methoxy, propyl-3-ethoxy, butyl-2-thiomethoxy, hexyl-4-amino, hexyl-3-N,N'-dimethylamino, methyl-N,N'-dioctylamino, 2-methyl-hexyl-4-amino.

[0047] For the purpose of this specification and the following claims, the term "aryl" refers to an aromatic carbocyclic group containing 6 to 60 carbon atoms. The aryl group may be optionally substituted by one or more groups selected from the following groups, which may be the same or different from each other: halogen atoms, for example, fluorine, chlorine, bromine, preferably fluorine; hydroxyl; C1-C 12 Alkyl; C1-C 12 Alkoxy; C1-C 12 Thioalkoxy; C3-C 24 trialkylsilyl; polyethyleneoxy; cyano; amino; C1-C 12a mono- or di-alkylamino group; a nitro group. Specific examples of the aryl group are: phenyl, methylphenyl, mesityl, methoxyphenyl, hydroxyphenyl, phenoxyphenyl, fluorophenyl, pentafluorophenyl, chlorophenyl, bromophenyl, nitrophenyl, dimethylaminophenyl, naphthyl, phenylnaphthyl, phenanthrene, anthracene.

[0048] For the purpose of this specification and the following claims, the term "heteroaryl" refers to a heterocyclic aromatic five- or six-atom group, which may also be a benzo-fused ring or a heterobicyclic ring, containing 4 to 60 carbon atoms and 1 to 4 heteroatoms selected from nitrogen, oxygen, sulfur, silicon, selenium, phosphorus. The heteroaryl group may be optionally substituted by one or more groups selected from the following, which may be the same or different from each other: halogen atoms, such as fluorine, chlorine, bromine, preferably fluorine; hydroxyl; C1-C 12 Alkyl; C1-C 12 Alkoxy; C1-C 12 Thioalkoxy; C3-C 24 trialkylsilyl; polyethyleneoxy; cyano; amino; C1-C 12 a mono- or di-alkylamino group; a nitro group. Specific examples of heteroaryl groups are: pyridine, picoline, methoxypyridine, phenylpyridine, fluoropyridine, pyrimidine, pyridazine, pyrazine, triazine, tetrazine, quinoline, quinoxaline, quinazoline, furan, thiophene, hexylthiophene, bromothiophene, dibromothiophene, pyrrole, oxazole, thiazole, isothiazole, oxadiazole, thiadiazole, pyrazole, imidazole, triazole, tetrazole, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, benzooxadiazole, benzothiadiazole, benzopyrazole, benzimidazole, benzotriazole, triazolopyrimidine, and coumarin.

[0049] For the purpose of this specification and the following claims, the term "cycloalkyl" refers to a cycloalkyl group having 3 to 30 carbon atoms. The cycloalkyl group may be optionally substituted by one or more groups selected from the following groups, which may be the same or different from each other: a halogen atom, for example, fluorine, chlorine, bromine, preferably fluorine; a hydroxyl group; a C1-C 12 Alkyl; C1-C 12 Alkoxy; C1-C 12 Thioalkoxy; C3-C 24 trialkylsilyl; polyethyleneoxy; cyano; amino; C1-C 12 a mono- or di-alkylamino group; a nitro group. Specific examples of the cycloalkyl group are: a cyclopropyl group, a 2,2-difluorocyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a methoxycyclohexyl group, a fluorocyclohexyl group, a phenylcyclohexyl group, a decalinyl group, a rosinyl group.

[0050] For the purpose of this specification and the above claims, the term "heterocyclic group" refers to a saturated or unsaturated ring having 3 to 12 atoms, which contains at least one heteroatom selected from nitrogen, oxygen, sulfur, silicon, selenium, phosphorus, optionally fused to other aromatic or non-aromatic rings. The heterocyclic group may be optionally substituted by one or more groups selected from the following, which may be identical or different from each other: halogen atoms (e.g., fluorine, chlorine, bromine, preferably fluorine), hydroxyl, C1-C 12 Alkyl; C1-C 12 Alkoxy; C1-C 12 Thioalkoxy; C3-C 24 trialkylsilyl; polyethyleneoxy; cyano; amino; C1-C 12 Specific examples of heterocyclic groups are: pyrrolidine, methoxypyrrolidine, piperidine, fluoropiperidine, methylpiperidine, dihydropyridine, piperazine, morpholine, thiazine, indoline, phenylindoline, 2-ketoazetidine, diketopiperazine, tetrahydrofuran, tetrahydrothiophene.

[0051] For the purposes of this specification and the following claims, the term “C1-C 20 "Dialkyl-amino" refers to an amino group containing two C1-C 12 A group of nitrogen atoms to which an alkyl group is bonded. Specific examples of the dialkylamino group are: dimethylamino, diethylamino, dibutylamino, diisobutylamino.

[0052] For the purposes of this specification and the following claims, the term “C1-C 20 "Alkoxy" refers to a group containing an oxygen atom, a straight or branched, saturated or unsaturated C1-C 20 The alkyl group is bonded to the oxygen atom. 20 Specific examples of the alkoxy group are methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, dodecyloxy.

[0053] According to a preferred embodiment of the present invention, the fullerene content of the fullerene functionalized vinyl polymer having the general formula (I) is greater than or equal to 35 wt%, preferably 45 wt% to 75 wt%, relative to the total weight of the fullerene functionalized vinyl polymer.

[0054] According to a preferred embodiment of the present invention, the hydroxyl (-OH) content of the fullerene functionalized vinyl polymer having the general formula (I) is greater than or equal to 0.1 wt%, preferably 0.5 wt% to 15 wt%, relative to the total weight of the fullerene functionalized vinyl polymer having the general formula (I).

[0055] As mentioned above, the present invention also relates to a method for preparing the fullerene-functionalized vinyl polymer having the general formula (I).

[0056] Therefore, another subject of the present invention is a process for preparing fullerene-functionalized vinyl polymers of the general formula (I), which comprises subjecting at least one vinyl polymer of the general formula (II):

[0057]

[0058] in:

[0059] - x is a fraction from 0 to 0.99, preferably from 0 to 0.6;

[0060] -y is an integer or fraction from 0.01 to 1, preferably from 0.05 to 0.8;

[0061] -The premise is that the sum of x+y is equal to 1;

[0062] - p is an integer from 10 to 10000, preferably from 20 to 5000;

[0063] and at least one fullerene derivative having the general formula (III):

[0064]

[0065] wherein R, n and w have the same meanings as above, and X represents a hydroxide anion or a halogen anion, for example, a chloride ion, a bromide ion, an iodide ion, preferably a hydroxide anion or a chloride ion, more preferably a hydroxide anion;

[0066] React in the presence of:

[0067] - organic solvents or mixtures of organic solvents;

[0068] - at least one substituted pyridine having the general formula (IV):

[0069]

[0070] Wherein R1 represents a hydrogen atom; or is selected from C1-C 20 , preferably C1-C 10 a linear or branched, saturated or unsaturated alkyl group optionally containing a heteroatom, an optionally substituted aryl group, an optionally substituted heteroaryl group, an optionally substituted cycloalkyl group, an optionally substituted heterocyclic group, or a C1-C 20 , preferably C2-C 10 A straight or branched, saturated or unsaturated dialkyl-amino group, C1-C 20 , preferably C2-C 10Straight or branched, saturated or unsaturated alkoxy, amino, cyano, hydroxyl; preferably R1 is methyl, tert-butyl, vinyl, dimethylamino, methoxy, more preferably dimethylamino;

[0071] - at least one substituted carbodiimide of the general formula (V):

[0072]

[0073] Wherein R2 and R3 are the same or different from each other and are selected from C1-C 20 , preferably C1-C 10 Preferably, R2 and R3 are ethyl, isopropyl, cyclohexyl, 3-dimethylaminopropyl, more preferably cyclohexyl.

[0074] According to a preferred embodiment of the present invention, the organic solvent may be selected from, for example, dimethyl sulfoxide (DMSO), xylene, toluene, mesitylene, tetrahydrofuran (THF), methyltetrahydrofuran (Me-THF), and dioxane.

[0075] According to a particularly preferred embodiment of the present invention, the organic solvent mixture is a mixture of organic solvents which can be selected from, for example, the following: dimethyl sulfoxide (DMSO), xylene, toluene, mesitylene, in a ratio of 1 / 1 v / v, more preferably a mixture of dimethyl sulfoxide (DMSO) / toluene (1 / 1 v / v), a mixture of dimethyl sulfoxide (DMSO) / xylene (1 / 1 v / v).

[0076] According to a preferred embodiment of the present invention, the vinyl polymer having the general formula (II) and the fullerene derivative having the general formula (III) can be used in a molar ratio relative to the molar amount of -OH groups contained in the vinyl polymer having the general formula (II), and the molar ratio is 10 to 0.1, preferably 5 to 0.25, and even more preferably 2.5 to 0.8.

[0077] According to a preferred embodiment of the present invention, the substituted pyridine having the general formula (IV) can be selected from, for example, 4-dimethylaminopyridine (DMAP), 4-methylpyridine, 4-tert-butylpyridine, 4-vinylpyridine, 4-methoxypyridine, 4-hydroxypyridine or a mixture thereof; preferably 4-dimethylaminopyridine (DMAP).

[0078] According to a preferred embodiment of the present invention, the carbodiimide having the general formula (V) can be selected from, for example, N,N'-dimethylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-di-3-dimethylaminopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide (DCC) or a mixture thereof; preferably N,N'-dicyclohexylcarbodiimide (DCC).

[0079] According to a preferred embodiment of the present invention, the substituted pyridine having the general formula (IV) may be used in a molar ratio of 0.9 to 0.1, preferably 0.6 to 0.4, relative to the total moles of the fullerene derivative having the general formula (III).

[0080] According to a preferred embodiment of the present invention, the carbodiimide having the general formula (V) may be used in a molar ratio of 9 to 1, preferably 6 to 4, relative to the total moles of the fullerene derivative having the general formula (III).

[0081] According to a preferred embodiment of the present invention, the method may be carried out at a temperature of 15°C to 150°C, preferably 20°C to 90°C.

[0082] According to a preferred embodiment of the present invention, the method may be carried out for a period of 2 hours to 96 hours, preferably 20 hours to 90 hours.

[0083] As described above, the fullerene-functionalized vinyl polymers of the general formula (I) can be advantageously used as electron acceptor compounds in organic photovoltaic devices (or solar devices) on rigid or flexible supports (e.g., binary, ternary, quaternary organic photovoltaic cells (or solar cells), organic photovoltaic modules (or solar modules) with simple or "tandem" structures). In addition, the fullerene-functionalized vinyl polymers of the general formula (I) can be advantageously used in perovskite-based photovoltaic cells (or solar cells) in the electron transport layer (ETL). In addition, the fullerene-functionalized vinyl polymers of the general formula (I) can be advantageously used in the production of organic thin film transistors (OTFTs) or organic field effect transistors (OFETs).

[0084] Therefore, another subject of the present invention is an organic photovoltaic device (or solar device) on a rigid support or a flexible support (for example, an organic binary, ternary, quaternary solar cell, an organic photovoltaic module (or solar module) with a simple or "tandem" structure), which comprises at least one fullerene-functionalized vinyl polymer of the specific general formula (I).

[0085] Another subject of the present invention is a perovskite-based photovoltaic cell (or solar cell) in which the electron transport layer (ETL) comprises at least one fullerene-functionalized vinyl polymer of the specific general formula (I).

[0086] A further subject of the present invention is an organic thin film transistor (OTFT) or an organic field effect transistor (OFET) comprising at least one fullerene-functionalized vinyl polymer of the specific general formula (I).

[0087] In order to better understand the invention and put it into practice, some illustrative and non-limiting examples are reported below.

[0088] The following characterization methods were used in the following examples.

[0089] NMR spectroscopy

[0090] NMR spectra of the obtained compounds were carried out using a NMR Bruker Avance 400 spectrometer.

[0091] For this purpose, about 10 mg of the sample to be measured are dissolved directly in about 0.8 ml of a suitable deuterated solvent on a glass tube for the measurement. The chemical shift scale is calibrated relative to the tetramethylsilane signal adjusted to 0 ppm.

[0092] FT-IR spectroscopy

[0093] FT-IR spectra were recorded by Thermo Nicolet Nexus 670 and Bruker IFS 48 spectrophotometers.

[0094] The FT-IR spectra of the polymers were obtained from thin films of the polymers on potassium bromide (KBr) sheets, obtained by depositing a solution of the polymer to be analyzed in hot 1,2-dichlorobenzene. The concentration of the polymer solution analyzed was equal to 10% by weight relative to the total weight of the polymer solution.

[0095] Thermogravimetric analysis (TGA)

[0096] Thermogravimetric analysis (TGA) using TA The Q500 instrument was operated by gradually increasing the temperature from 50°C to 300°C (at a rate of 20°C / min) under a nitrogen atmosphere and continuously recording the weight change of the sample.

[0097] Example 1

[0098] Preparation of Fullerene Derivative PCBA

[0099]

[0100] The fullerene derivative PCBA was prepared according to the method reported by Hummelen JC et al., "The Journal of Organic Chemistry" (1995), Vol. 60, pp. 532-538, by hydrolyzing [6,6]-phenyl-C 61 -Butyric acid methyl ester (PC61BM) was used for the experiment.

[0101] To this end, 56 ml of concentrated hydrochloric acid (HCl) (VWR, 37% in water) and 139 ml of glacial acetic acid (Merck, purity >97%) were added to a 1-liter two-necked flask equipped with a magnetic stirrer. 61 -Butyric acid methyl ester (PC61BM) (2 g, 2.2 mmol) (Solenne Bv, purity> 99%) in 330 ml of toluene (VWR, purity> 99.5%): the reaction mixture obtained was heated and kept at reflux for 48 hours under stirring. Subsequently, the temperature was naturally reduced to room temperature (25°C) and the solvent was removed by vacuum evaporation: the residue was washed with diethyl ether (Merck, purity> 99%) (3×10 ml), toluene (Merck, purity> 99%) (3×10 ml), and again with diethyl ether (Merck, purity> 99%) (2×10 ml), and finally dried under vacuum at room temperature (25°C) for 6 hours to obtain 1.85 g of the fullerene derivative PCBA, corresponding to a yield of 94%.

[0102] Fullerene derivative PCBA was analyzed by thermogravimetric analysis ( Figure 1 ) and FT-IR spectra ( Figure 2 ) for characterization.

[0103] Example 2

[0104] Fullerene-functionalized vinyl polymer C 60 Preparation of -PVA-co-PE (CC365)

[0105]

[0106] Fullerene-functionalized vinyl polymer C 60 -PVA-co-PE(CC365) was synthesized as follows.

[0107] To this end, 100 mg of polyvinyl alcohol-ethylene copolymer (PVA-co-PE) (Sigma-Aldrich-Lot #MKBV2573, ethylene 32 mol %, Tg=69°C, 1.75 mmol of -OH groups) were dissolved in an inert atmosphere in 15 ml of a dimethyl sulfoxide (DMSO) (Merck, purity >99%) / toluene (VWR, purity >99.5%) mixture (1:1, v / v) in a 100 ml two-necked flask equipped with a magnetic stirrer: the reaction mixture was kept at 40°C for 14 hours under stirring. Subsequently, PCBA (547 mg, 0.61 mmol), 4-dimethylaminopyridine (DMAP) (Merck, purity>99%) (0.16 mmol) and NN'-dicyclohexylcarbodiimide (DCC) (Merck, purity>99%) (1.63 mmol) obtained as described in Example 1 were added in 10 ml of a dimethyl sulfoxide (DMSO) (Merck, purity>99%) / toluene (VWR, purity>99.5%) mixture (1:1, v / v). Under stirring, the resulting reaction mixture was maintained at 40°C in an inert atmosphere for 72 hours. Subsequently, the temperature was naturally lowered to room temperature (25°C), 50 ml of distilled water was added to the reaction mixture to obtain two phases, which were separated using a separatory funnel, the aqueous phase was treated with toluene (VWR, purity>99.5%) (3×10 ml), and the resulting organic phase was combined with the reaction mixture. Subsequently, toluene was removed by vacuum evaporation at room temperature (25°C). The solid residue obtained was treated with 25 ml of tetrahydrofuran (THF) [Merck, purity 99.9%, containing 250 ppm of butylhydroxytoluene (BHT), previously filtered on neutral alumina to remove the BHT present in the commercial product] to remove any unreacted PCBA, and the resulting suspension was kept at room temperature for 1 hour under stirring. Subsequently, the suspension was centrifuged, and traces of insoluble matter deposited at the bottom of the container were removed by sedimentation and subsequent filtration through a 0.4 mm polytetrafluoroethylene (PTFE) filter. The resulting clear solution was concentrated to a volume of 5 ml under vacuum at room temperature (25° C.) and added dropwise to cold n-hexane (Merck, purity 95%) (100 ml) to obtain a brown solid precipitate. The brown solid was recovered by vacuum filtration on a Buchner filter and washed on the filter with cold n-hexane (VWR, purity 95%) (2×10 ml), methanol (Merck) (2×10 ml) and diethyl ether (Merck, >99%) (2×10 ml), and finally dried in an oven at 60° C. overnight to obtain 384 mg of fullerene-functionalized vinyl polymer C. 60 -PVA-co-PE(CC365), corresponding to a yield of 61%.

[0108] Fullerene-functionalized vinyl polymer C60 -PVA-co-PE(CC365) passed 1 H-NMR spectra [400 MHz, at d 1 Chloroform (VWR, purity> 99.8%)] to obtain Figure 3 Spectra reported in .

[0109] Fullerene-functionalized vinyl polymer C 60 -PVA-co-PE(CC365) was also characterized by thermogravimetric analysis ( Figure 1 ), from which it can be determined that the amount of residual fullerene in the polymer is equal to 69% by weight: From this data, it is deduced that, with respect to the fullerene-functionalized vinyl polymer having the general formula (I), x=0.32, y=0.44 and z=0.24, while from this data the content of -OH groups is calculated, and it is found that relative to the fullerene-functionalized vinyl polymer C 60 -PVA-co-PE(CC365), the content of -OH groups is equal to 3.6% by weight.

[0110] Example 3

[0111] Fullerene-functionalized vinyl polymer C 60 Preparation of -PVA-co-PE (CC370)

[0112]

[0113] Fullerene-functionalized vinyl polymer C 60 -PVA-co-PE(CC370) was prepared as follows.

[0114] To this end, 100 mg of polyvinyl alcohol-ethylene copolymer (PVA-co-PE) (Sigma-Aldrich-Lot #MKBV2573, ethylene 32 mol%, Tg=69°C, 1.75 mmol-OH groups) were dissolved in an inert atmosphere in 15 ml of a dimethyl sulfoxide (DMSO) (Merck, purity >99%) / xylene (Merck, purity >98%) mixture (1:1, v / v) in a 100 ml two-necked flask equipped with a magnetic stirrer: the reaction mixture was kept at 40°C for 14 hours under stirring. Subsequently, PCBA (395 mg, 0.44 mmol), 4-dimethylaminopyridine (DMAP) (Merck, purity>99%) (0.16 mmol) and N,N'-dicyclohexylcarbodiimide (DCC) (Merck, purity>99%) (1.63 mmol) obtained as described in Example 1 in a 10 ml dimethyl sulfoxide (DMSO) (Merck, purity>99%) / toluene (VWR, purity>99.5%) (1:1, v / v) mixture solution were added. The resulting reaction mixture was kept at 40° C. in an inert atmosphere for 72 hours under stirring. Subsequently, the operation described in Example 2 was performed to obtain 276 mg of fullerene-functionalized vinyl polymer C 60 -PVA (CC370), corresponding to a yield of 58%.

[0115] Fullerene-functionalized vinyl polymer C 60 -PVA-co-PE(CC370) 1 H-NMR spectra [400 MHz, at d 1 Chloroform (VWR, purity> 99.8%)] to obtain Figure 4 Spectra reported in .

[0116] Fullerene-functionalized vinyl polymer C 60 -PVA-co-PE(CC370) was also characterized by thermogravimetric analysis ( Figure 1 ), from which it can be determined that the amount of residual fullerene in the polymer is equal to 65% by weight: From this data, it is deduced that, with respect to the fullerene-functionalized vinyl polymer having the general formula (I), x=0.32, y=0.51 and z=0.17, while from this data the content of -OH groups is calculated, and it is found that relative to the fullerene-functionalized vinyl polymer C 60 -PVA-co-PE(CC370), the content of -OH groups is equal to 4.6% by weight.

[0117] Fullerene-functionalized vinyl polymer C 60 -PVA-co-PE(CC370) was also characterized by IR spectroscopy ( Figure 2), where the presence of fullerene units in the polymer can be seen by the 525 cm -1 The presence of the absorption band was qualitatively confirmed.

Claims

1. Fullerene-functionalized vinyl polymers having the general formula (I): in: - x is a fraction from 0 to 0.89, preferably from 0 to 0.6; -y is a fraction ranging from 0.01 to 0.9, preferably from 0.02 to 0.7; - z is a fraction from 0.1 to 0.99, preferably from 0.05 to 0.8; -The premise is that the sum of x+y+z is equal to 1; - p is an integer from 10 to 10000, preferably from 20 to 5000; -w is an integer from 50 to 250, preferably from 60 to 90, more preferably 60, 70, 84; - n is an integer from 1 to 12, preferably from 2 to 6; -R represents a hydrogen atom; or is selected from C1-C 20 , preferably C1-C 10 The straight-chain or branched, saturated or unsaturated alkyl group which may contain heteroatoms, the aryl group which may be substituted, the heteroaryl group which may be substituted, the cycloalkyl group which may be substituted, the heterocyclyl group which may be substituted; preferably, hydrogen.

2. The fullerene-functionalized vinyl polymer of claim 1, wherein the fullerene content of the fullerene-functionalized vinyl polymer of the general formula (I) is greater than or equal to 35 wt. %, preferably 45 wt. % to 75 wt. %, relative to the total weight of the fullerene-functionalized vinyl polymer.

3. The fullerene-functionalized vinyl polymer of claim 1 or 2, wherein the hydroxyl (-OH) content of the fullerene-functionalized vinyl polymer of the general formula (I) is greater than or equal to 0.1 wt%, preferably 0.5 wt% to 15 wt%, relative to the total weight of the fullerene-functionalized vinyl polymer of the general formula (I).

4. A process for preparing a fullerene-functionalized vinyl polymer of formula (I) according to any one of the preceding claims, comprising subjecting at least one vinyl polymer of formula (II): - x is a fraction from 0 to 0.99, preferably from 0 to 0.6; -y is an integer or fraction from 0.01 to 1, preferably from 0.05 to 0.8; -The premise is that the sum of x+y is equal to 1; - p is an integer from 10 to 10000, preferably from 20 to 5000; and at least one fullerene derivative having the general formula (III): wherein R, n and w have the same meanings as above, and X represents a hydroxide anion or a halogen anion, such as a chloride ion, a bromide ion, an iodide ion, preferably a hydroxide anion or a chloride ion, more preferably a hydroxide anion; React in the presence of: - organic solvents or mixtures of organic solvents; - at least one substituted pyridine having the general formula (IV): Wherein R1 represents a hydrogen atom; or is selected from C1-C 20 , preferably C1-C 10 a linear or branched, saturated or unsaturated alkyl group optionally containing heteroatoms, an optionally substituted aryl group, an optionally substituted heteroaryl group, an optionally substituted cycloalkyl group, an optionally substituted heterocyclic group; or a C1-C 20 , preferably C2-C 10 A straight or branched, saturated or unsaturated dialkyl-amino group, C1-C 20 , preferably C2-C 10 Straight or branched, saturated or unsaturated alkoxy, amino, cyano, hydroxyl; preferably R3 is methyl, tert-butyl, vinyl, dimethylamino, methoxy, more preferably dimethylamino; - at least one substituted carbodiimide of the general formula (V): Wherein R2 and R3 are the same or different from each other and are selected from C1-C 20 , preferably C1-C 10 Preferably, R2 and R3 are ethyl or isopropyl, cyclohexyl, 3-dimethylaminopropyl, more preferably cyclohexyl.

5. The method for preparing a fullerene-functionalized vinyl polymer having the general formula (I) according to claim 4, wherein the organic solvent is selected from dimethyl sulfoxide (DMSO), xylene, toluene, mesitylene, tetrahydrofuran (THF), methyltetrahydrofuran (Me-THF), and dioxane.

6. A method for preparing a fullerene-functionalized vinyl polymer of general formula (I) according to claim 4 or 5, wherein the organic solvent mixture is a mixture of organic solvents selected from the group consisting of dimethyl sulfoxide (DMSO), xylene, toluene, mesitylene, in a ratio of 1 / 1 v / v, more preferably a mixture of dimethyl sulfoxide (DMSO) / toluene (1 / 1 v / v), a mixture of dimethyl sulfoxide (DMSO) / xylene (1 / 1 v / v).

7. A method for preparing a fullerene-functionalized vinyl polymer of general formula (I) according to any one of claims 4 to 6, wherein the vinyl polymer of general formula (II) and the fullerene derivative of general formula (III) are used in a molar ratio relative to the molar amount of -OH groups contained in the vinyl polymer of general formula (II), the molar ratio being from 10 to 0.1, preferably from 5 to 0.25, and even more preferably from 2.5 to 0.

8.

8. A method for preparing a fullerene-functionalized vinyl polymer having the general formula (I) according to any one of claims 4 to 7, wherein the substituted pyridine having the general formula (IV) is selected from 4-dimethylaminopyridine (DMAP), 4-methylpyridine, 4-tert-butylpyridine, 4-vinylpyridine, 4-methoxypyridine, 4-hydroxypyridine or a mixture thereof; preferably 4-dimethylaminopyridine (DMAP).

9. A method for preparing a fullerene-functionalized vinyl polymer of general formula (I) according to any one of claims 4 to 8, wherein the carbodiimide of general formula (V) is selected from N,N'-diethylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-di-3-dimethylaminopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide (DCC) or a mixture thereof; preferably N,N'-dicyclohexylcarbodiimide (DCC).

10. A process for preparing a fullerene-functionalized vinyl polymer of formula (I) according to any one of claims 4 to 9, wherein the substituted pyridine of formula (IV) is used in a molar ratio of 0.9 to 0.1, preferably 0.6 to 0.4, relative to the total moles of the fullerene derivative of formula (III).

11. A process for preparing a fullerene-functionalized vinyl polymer of formula (I) according to any one of claims 4 to 10, wherein the carbodiimide of formula (V) is used in a molar ratio of 9 to 1, preferably 6 to 4, relative to the total moles of the fullerene derivative of formula (III).

12. A process for preparing a fullerene-functionalized vinyl polymer having the general formula (I) according to any one of claims 4 to 11, wherein the process is carried out as follows: - at a temperature of 15°C to 150°C, preferably 20°C to 90°C; and / or - for a period of 2 to 96 hours, preferably 20 to 90 hours.

13. An organic photovoltaic device (or solar device) on a rigid or flexible support, such as an organic binary, ternary, quaternary solar cell, an organic photovoltaic module (or solar module) with a simple or "tandem" structure, comprising at least one fullerene-functionalized vinyl polymer of formula (I) according to any one of claims 1 to 12.

14. Perovskite-based photovoltaic cell (or solar cell), wherein the electron transport layer (ETL) comprises at least one fullerene-functionalized vinyl polymer having the general formula (I) according to any one of claims 1 to 12.

15. An organic thin film transistor (OTFT) or an organic field effect transistor (OFET) comprising at least one fullerene-functionalized vinyl polymer of formula (I) according to any one of claims 1 to 12.

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