WO2012116017A2

WO2012116017A2 - Polythiophene–fullerene conjugates for photovoltaic cells

Info

Publication number: WO2012116017A2
Application number: PCT/US2012/026035
Authority: WO
Inventors: Reuben Rieke
Original assignee: Rieke Metals Inc.
Priority date: 2011-02-24
Filing date: 2012-02-22
Publication date: 2012-08-30
Also published as: WO2012116017A3; TW201238995A

Abstract

Compositions suitable for manufacture of high-efficiency organic photovoltaic devices, and methods of preparing the compositions, are provided. Polythiophene-fullerene conjugates, wherein a conductive polythiophene polymer, such as a regioregular polythiophene, and a fullerene derivative, are constructed with defined spacing between the electron donor polythiophene and electron acceptor fullerene. Photovoltaic devices containing films including the inventive compositions can provide improved photoefficiencies for solar electrical generation with the flexible, relatively inexpensive, organic photovoltaic materials described herein.

Description

POLYTHIOPHENE-FULLERENE CONJUGATES FOR

PHOTOVOLTAIC CELLS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. Provisional

Application Serial Number 61/446,234, filed February 24, 2011, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

Photovoltaic cells using organic materials, rather than mono-crystalline silicon, as the light-absorbing, electron-generating substrate offer the promise of low-cost, possibly flexible, solar panels for electrical generation, such as for residences, consumer electronic devices, remote location electrical sources, and the like. Mono-crystalline silicon and other inorganic photovoltaic materials can be expensive and of low efficiency, as well as presenting handling challenges due to unfavorable physical properties. Photovoltaic devices based on organic materials may circumvent some of these issues and make solar electricity an economic reality.

Polythiophene polymers are known to be effective electron donors in organic photovoltaic cells, wherein photo-excited electrons are accepted by materials having an effective electron affinity. See, for example: T. Akikyama et al., "Solid-State Solar Cells Consisting of Poly thiophene- Porphyrin Composite Films", Jpn. J. Appl. Phys. (2005), 44 2799-2802; J. Nakamura, et al., "The Photovoltaic Mechanism of a Polythiophene/Perylene Pigment Two-Layer Solar Cell", Bulletin ofthe Chemical Society of Japan (2004), 77(12) 2185-2188; R. Radbeh, et al., "Nanoscale control of the network morphology of high efficiency polymer fullerene solar cells by the use ofhigh material concentration in the liquid phase", Nanotechnology (2010), 21, 1-8; B. Fan, et al.,

"Polythiophene/fullerene bulk heterojunction solar cell fabricated via electrochemical co-deposition", Solar Energy Materials and Solar Cells (2006), 90(20), 3547-3556; all of which, and references cited therein, are incorporated by reference herein.

A polythiophene bearing a single fullerene as a polymer-terminating group has been prepared; see J. Lee, et al., "Synthesis of C60-end capped P3HT and its application for high performance of P3HT/PCBM bulk heteroj unction solar cells", J. Mater. Chem. (2010), 20, 3287-3294.

In Radbeh, et al., it is stated that maximization of the interfacial area of the donor and acceptor components of an organic photovoltaic cell is desirable to enhance efficiency of electrical generation, and the use of interpenetrating nanoscale networks of a polythiophene component and a fullerene component is discussed.

Polythiophenes are a known class of conductive polymer that are suitable as electron donors in organic photovoltaic cells. The polythiophene can be a regioregular polythiophene, such as an H-T 2,5-polythiophene, such as can be prepared according to U.S. Pat. No. 7572880 and U.S. published application Nos. 2010/0004423 and 2010/031 1879 by the inventor herein.

SUMMARY

The present invention is directed to compositions for use in organic photovoltaic cells, such as those wherein polythiophene / fullerene

interpenetirating networks have previously been used, and to methods of preparation of the composition; to electrically active films comprising the compositions; to photovoltaic cells or devices in which the inventive compositions are used, and to methods of preparing such photovoltaic cells.

In various embodiments, the invention provides a composition for photovoltaic electrical generation, comprising a polythiophene polymer having thienyl repeating units, wherein at least some of the thienyl repeating units not disposed at a polymer chain terminus are covalently or ionically bonded via respective linkers to respective fullerene groups. Fullerene groups are disposed along the backbone of the polythiophene polymeric chain, and multiple fullerene groups can be covalently or ionically attached to a single polymer molecule. Substantially every thienyl repeating unit can bear a fullerene group bonded thereto, or lower proportions of the thienyl repeating units can bear fullerenes, which can be randomly distributed along the polymer chain, or can be present in blocks of the polymer chain.

In various embodiments, the invention provides a film comprising any of the compositions of the invention. The electrically active film can be suitable for assembly into arrays of photovoltaic generation cells or units for manufacture of a solar panel using organic materials.

In various embodiments, the invention provides a method of preparing a composition of the invention, comprising contacting a polythiophene polymer bearing a linker precursor group and a fullerene suitable to react with the linker precursor group to form either a covalent or an ionic bond.

In other embodiments, the invention provides a method of preparing a composition of the invention, comprising polymerizing a fullerene-substituted 2,5 -dihalothiophene and, optionally, copolymerizing a 2,5-dihalothiophene that does not bear a fullerene group, in the presence of a metal catalyst.

In vari ous embodiments, the invention provides a method of preparing a film comprising applying a composition made by a method of the invention to a surface, optionally in solution followed by evaporation of the solvent.

In various embodiments, the invention provides a photovoltaic device comprising the composition or film of the invention, of a composition or film prepared by a method of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a photovoltaic device according to an embodiment of the invention.

FIG. 2 shows another example of a photovoltaic device according to an embodiment of the invention.

DETAILED DESCRIPTION

Definitions

A "fullerene", as the term is used herein refers to the family of spheroidal allomorphs of carbon and derivatives thereof. Accordingly, C60 and C61 fullerenes and derivatives can include

fullerene

as well as C70- and C71 -fullerenes and related species. Some examples include:

A C61 -fullerene derivative (R = H, PCBA; R = Me, PCBM)

(6,6)-Phenyl-C61 butyric acid (PCBA)

(6,6)-Phenyl-C61 -butyl-Z (PCB-yl-Z) e.g., Z = OH = PCBylOH

Z = leaving group = PCByl-LG (e.g., mesylate, etc.)

The structure shown above labeled as C60- fullerene is termed an

''underivatized fullerene", whereas the C61 -fullerene compounds are

"derivatized Mlerenes" or "fullerene derivatives" as the terms are used herein. For example, a C61 -fullerene can be prepared by reaction of a carbene precursor reagent and an underivatized fullerene wherein the carbene inserts into a fullerene double bond to yield a cyclopropanyl group which can bear substituents on the non-bridgehead carbon atom such as in the case of PCBA. Various carbene-generating or carbene precursor reagents include diazo compounds, azides, chlorocarbene reagents (e.g, from dehydrohalogenation of dichloroalkyl groups), Fischer carbene reagents (carbene-metal complexes) and the like. See, for example, N. Bespalova, "Cyclopropanation of

Buckminsterfullerene by Olefin Metathesis Reaction", Russ. Chem. Bull. (1996), 45(5), 1255-1256, and references cited therein. The structure above labeled C61 -fullerene is an unsubstituted C61 -fullerene, whereas PCBA and the like are substituted C61 -fullerenes.The term "fullerene" as used herein also encompasses analogous C70- and C71 -fullerenes, both underivatized and derivatized, analogously to the C60- and C61 -fullerenes. A compound such as PCBA, or any fullerene derivative incorporating a carboxylic acid group is referred to as a "fullerene carboxylic acid; similarly a fullerene derivative incorporating a carboxylic ester group such as PCBM is referred to as a "fullerene carboxylic ester", a fullerene derivative incorporating a reactive hydroxyl group is referred to as a "fullerene carbinol", a fullerene derivative incorporating an aldehyde group is referred to as a "fullerene carboxaldehyde", a fullerene derivative incorporating an amino group is referred to as a "fullerene amine", and so forth.

A "cationic fullerene" or "cationic fullerene derivative" as the terms are used herein refer to a fullerene hearing a positive charge at an operative pH; the positive charge can be permanent as in the case of a quaternary ammonium fullerene, or can be pH-dependent as in the case of an amino fullerene. An example of a cationic fullerene is the species shown below:

See, for example, R. Bullard-Dillard, et al., "Tissue Sites of Uptake of ¹⁴C- labeled C60" (1996), Bioorg. Chem., 24, 376, incorporated by reference herein. Another example of a cationic fullerene is a choline ester of PCB A or a choline ether ofPCByl-OH:

A choline or other quaternary ester (structure(A) above), or a choline ether (structure (B) above), can be prepared by reaction of choline with, respectively, an activated ester of PCBA, or an activated carbinol derived from PCBA by, for example, diborane reduction, followed by activation for nucleophilic displacement, for example by formation of a triflate ester, followed by reaction with choline. Other C61 -fullerenes can likewise be suitably derivatized with cationic groups such as quaternary ammonium ion bearing groups, as are known in the art and can be prepared by art methods.

An "anionic fullerene" or "anionic fullerene derivative" as the term is used herein refers to a fullerene bearing a negative electrical charge at an operative pll; for example the carboxylate form of PCBA is an anionic fullerene within the meaning herein; a fullerene alkyl sulfonate derivative is another example of an anionic fullerene.

The depictions herein of C60-fullerenes, to avoid confusion, do not show the bonds that are present on the rear face of the molecule as shown, but it is understood that fullerenes are hollow and have the bond pattern as shown repeated on the rear face, such that fullerenes are roughly spherical or spheroidal. An alternati ve depiction of a C60-fullerene showing the bonding on the rear face of the molecule is as shown below.

In this depiction, bonds on the rear face are shown in grey tone.

It is recognized that the butyl or butanoyl chains of PCBA and its esters or carbinol derivatives or other derivatives can be replaced with linking chains of various lengths. By variation of such linking chains, the spacing between the polythiophene backbone and the fullerene unit can be systematically varied. It is believed that differing linker chain lengths can result in differing efficiencies of electron transfer from polythiophene to fullerene under illumination.

Further fullerene derivatives that can be incorporated into a

polythiophene-fullerene conjugate of the invention can have other suitable modifications to the core spherical/spheroidal fullerene structure. Any such derivative that bears a functional group that can be coupled, either covalently or ionically, with a linker precursor group on a polythiophene polymer background can be used. Carbene-insertion reaction products of fullerenes and carbene- generating reagents, such as diazo compounds and the like, can provide a range of groups other than the phenyl, carboxyalkyl cyclopropanyl insertion product of PCBA. Furthermore, although the derivative shown in mono-substituted with a cyclopropanyl ring, fullerene derivatives within the meaning herein can be di- substituted, or more, provided that the substitutions of the fullerene core do not destroy the electron-accepting properties of the fullerene system necessary for operation in a photovoltaic generation device.

A "polythiophene" or "polythiophene polymer" as the terms are used herein refer to polymers wherein the repeating unit is a thiophene, often termed a thienyl group or unit, which is coupled directly to other thiophene units such that the polymer contains a conjugated electronic system. Some such conjugated polythiophene polymers are known to be electrically conductive.

An example of a 2,5 -polythiophene is shown; the 3- and 4-positions of each thiophene ring can be substituted. Chain terminating groups can be hydrogen, halogen, alkyl, or other monovalent groups, depending upon method of synthesis. See, for example, U.S. Pat. No. 7572880 and U.S. published application Nos. 2010/0004423 and 2010/031 1879 by the inventor herein.

Degree of polymerization values can run from oligomeric lengths (e.g., n of about 8 or 9) up through multiple thousands, corresponding to polymer molecular weights (weight average molecular weights) from about 1,000 (DP ~ 10) to at least about 200,000 (DP ~ 2,000) and more. Polythiophenes can also be 2,4- or 3 ,4-polythiophenes, as defined by the positions of bonding on each thiophene ring, or can be random mix tures. The point of attachment of the fullerene is at a carbon atom not involved in the thienyl-thienyl bonding of the polymer backbone, e.g., at a 3- or 5-position for a 2,4-polythiophene, or at a 2- or a 5- position for a 3 ,4-polythiophene. Regioregular polythiophenes are polymeric form wherein the positions of bonding are uniform for each repeating unit. An example of a regioregular 2,5-polythiophene is shown below, wherein each star indicates a continuing polythiophene chain, each with a terminal group at the respective end of the polymeric chain of the molecule.

(a regioregular 2,5 -polythiophene) Each thiophene unit can be substituted, e.g., a regioregular 2,5- polythiophene can bear a substituent on the 3 -position, the 4-position, or both, of each thiophene ring repeating unit. For every pair of thiophene repeating unit, the dimeric unit comprising the pair of thiophenes can be coupled head-to-tail (TIT), head-to-head (HH), or tail-to-tail(TT), depending on the distribution of the substituents on the di-thiophene unit. For a regioregular 2,5-polythiophene, when 3-substituent and 4-substituent aire identical, the forms are degenerate (identical), but for a regioregular 3-suhstituted-2,5-polythiophene, the isomeric forms of each di-thiophene unit can be as shown below.

wherein a star indicates a continuing polymer chain with a terminus.

Any polythiophene polymer comprising mono-substituted thiophene repeating units or di-substituted thiophene repeating units substituted with two different groups, can include a mixture of these three isomeric dimer forms. A fully regioregular HT polythiophene, however, includes only or at least predominantly the HT form; polythiophenes containing HH dimers necessarily also contain TT or HT dimers, or both. Polythiophene polymers well suited for formation of the covalent fullerene conjugates as described herein and their use in photovoltaic cells are regioregular HΤ- 2,5 -poly thiphenes, comprising monosubstituted thiophene repeating units, of formula

, wherein the star (*) indicates a continuing polythiophene chain, which can be of the same structural type, wherein each chain bears a respective terminal atom or group. See, for example, U.S. Pat. No. 7572880, and U.S. published application Nos. 2010/0004423 and 2010/0311879 by the inventor herein.

Polythiophene-fullerene covalent conjugates, as the term is used herein, refers to polythiophenes wherein fuller ene units are covalently or ionically coupled thereto via a thiophene substituent, i.e., are not themselves incorporated between thiophene units in the polymeric chain. For example, in the case of a regioregular HT-monosubstituted-2,5-poiythiophene as shown above, fullerene units are covalently coupled to the polymer backbone via the X groups, as discussed below. Each X group need not bear a fullerene unit, although some proportion of X groups is bonded to a fullerene unit. The degree of substitution of the polythiophene backbone with fullerene units can range from 1 in the case of an HT-monosubstituted-2,5-polythiophene wherein every thienyl unit bears a fullerene, down to 0.01 or less, wherein one or fewer of every hundred thienyl units, on average, bears a fullerene.

A "covalent conjugate" as the term is used herein refers to a molecular species in which the polythiophene polymer chain and the fullerene are bonded by covalent organic bonds, such as single bonds or double bonds. Covalent conjugates can be formed by any appropriate bond-forming technique known in the art of organic synthesis, provided suitable precursors having reactive groups on both the polythiophene and the fullerene can be obtained. For instance, covalent conjugates of the invention can be prepared by condensation of a carboxylic acid or a derivative group on either the polythiophene or the fullerene with a respective alcohol or amino group on the reaction partner fullerene or polythiophene, such than an ester or an amide bond is formed in making the covalent conjugate. Or, an alkylation reaction involving a nucleophile and an electrophile can be used. Alternatively, a Wittig-type reaction can be carried out between an aldehyde derivative of either the polythiophene or the fullerene with a respective phosphonium ylide formed from the fullerene or the polythiophene. Linkers can include amine, amide, ester, anhydride, and other linkages that can be formed from appropriate precursors under conditions as are known in the art of organic synthesis. When it is stated that a thienyl repeating unit "bears" or "is covalently bonded to" a fullerene, what is meant is that the particular thienyl repeating unit is the repeating unit to which the fullerene is directly (via the linker) or primarily attached, although it is understood to also be bonded to other thienyl repeating units via the thieny l-thienyl bonds of the polymer.

An "ionic conjugate" as the term is used herein refers to a molecular entity wherein an electrically charged fullerene derivative and a polythiophene bearing a suitable electrically charged group of opposite polarity are associated via an ionic interaction. For example, a cationic fullerene derivative can form an ionic conjugate with an anionic polythiophene polymer by ionic bond formation between the anionic and cationic groups. For example, an anionic

polythiophene, such as a polythiophene substituted with an alkylcarboxylate substituent, can form an ionic conjugate with a cationic fullerene derivative, such as described above. Or, an anionic fullerene derivative such as a PCBA carboxylate anion can form an ionic conjugate with a cationic polythiophene derivative, such as a choline ester of a alkylcarboxylate substituted

polythiophene, or a polythiophene substituted with a quaternary ammonium group, such as can be formed be reaction of a polythiophene substituted with an alkyl group bearing a leaving group such as halo or a sulfonate ester, and a trialkylamine.

A "linker" or "linker group" as the terms used herein refers to an organic moiety covalently bonded to one or more thiophene rings of the polythiophene polymer, to which the fullerene (including a fullerene derivative) is itself covalently or ionically bonded. The linker can be any suitable arrangement of atoms that serves to bond the fullerene group, either covalently or ionically, to the polythiophene backbone, but can include alkylene, alkenylene, or alkynylene chains, optionally additionally comprising therein oxygen, nitrogen, and sulfur atoms, and can include functional groups in the chain such as ethers, esters, amides, ureas, urethanes, anhydrides and other similar groups. By an "alkylene" chain is meant an at least bifunctional alkyl group such as methylene, ethylene, etc., of formula -(0¾)η-. An "alkenylene" linker is an alkylene linker specifically incorporating at least one double bond (unsaturation). And

"alkynylene" linker is an alkylene linker incorporating at least one triple bond. Any of these linkers can further include addition functional groups, and can include heteroatoms, as discussed above. As used herein in reference to a linker, an "alkyl" linker comprises an "alkylene", an "alkenyl" linker comprises an "alkenylene", and an "alkynyl" linker comprises an "alkynylene"

A linker can be linear, or a linker can be branched, can include cyclic moieties including cycloalkyl, heterocyclyl, aryl and heteroaryl groups, or both. A linker can be formed in the process of coupling a fuller ene to a polythiophene, such as by the reaction of a suitably derivatized fullerene with a suitably derivatized polythiophene, e.g., a polythiophene bearing a "linker precursor group", with formation of a new covalent bond. As the term is used herein, a "linker precursor group" refers to a substituent on the polythiophene polymer backbone, that can undergo reaction with a fullerene derivative to yield a fullerene group covalently or ionically linked to the polythiophene polymer backbone via a linker.

For example, a fullerene derivative comprising a carboxylic acid group can be coupled with a polythiophene bearing an amino, such as an aminoalkyl, group, to form a linker comprising an amide bond. In this example, the aminoalkyl group on the polythiophene can be viewed as the linker precursor group. Alternatively, a fullerene derivative comprising a carboxylate anion can be coupled with a polythiophene bearing a cationic group, to form a linker comprising an ammonium salt of the carboxylic acid group. Or, a linker can be formed by the creation of a carbon-carbon single bond, such as by a C- alkylation reaction, e.g., alkylation of an enolate with an alkyl halide, alkyl sulfonate ester, or other alkyl bearing a leaving group, or by, e.g., formation of an organometallic reagent such as a Grignard or organolithium reaction and reaction with a suitable group such as an aldehyde, ketone, or ester. A linker can also be formed with creation of a new carbon-carbon double bond, such as by a Wittig type reaction of a phosphonium ylide with an aldehyde or ketone, or by other similar reactions such as a Horner- Wadsworth-Emmons reaction of a phosphonate anion with a carbonyl group, etc. While every thiophene (thienyl) repeating unit in the polythiophene polymer can bear a linker precursor group, in a fullerene-polythiophene conjugate of the invention, not every linker precursor group has reacted with a Mlerene derivative to provide a covalently or ionically coupled linker-fullerene substituent on the polythiophene. In various embodiments, only about 1%, or only about 1-5%, or only about 1-10%, of the thienyl repeating units, bear a linked fullerene derivative via a linker; a majority of thienyl repeating units can bear their respective linker precursor groups or derivatives thereof, unreacted with a fullerene derivative, while a minority of the thienyl repeating groups actually bear the covalently linker fullerene derivative bonded thereto. In other embodiments, up to 50%, or more, of the thienyl units can bear a fullerene group.

In various embodiments, a thienyl monomer unit bearing a fullerene bonded thereto can be polymerized using methods developed by the inventor herein to provide a fully fullerene-substituted polythiophene. Or, a thienyl unit bearing a fullerene bonded thereto can be copolymerized with other thienyl units not bearing fullerene units to prepare partly fullerene-substituted polythiophene.

The spacing between the polythiophene backbone and the pendant fullerene groups can have an effect on the efficiency of a photovoltaic device formed of the material. The length of the linker, and the rigidity of the linker, can serve to define an average separation between the electron-accepting fullerene group and the electron-donating polythiophene backbone.

As the term is used herein, a "film" refers to a self-supporting or freestanding fil that shows mechanical stability and flexibility, as well as to a coating or layer on a supporting substrate or between two substrates.

A "conjugate" or a "covalent conjugate" as the terms are used herein refer to two molecular entities that are conjoined by covalent or ionic chemical bonds, i.e., not just by non-bonding association or complexation. An example of a covalent bond is a carbon-carbon bond. An example of an ionic bond is a salt bond.

As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. The term "about" as used herein, when referring to a numerical value or range, allows for a degree of variability in the value or range, for example, within 10%, or within 5% of a stated value or of a stated limit of a range.

All percent compositions are given as weight-percentages, unless otherwise stated.

All average molecular weights of polymers are weight-average molecular weights, unless otherwise specified.

"DP" or "degree of polymerization" refers to the number of repeating units in a polymer molecule; for a polythiophene, the individual molecular weight of a thienyl unit, about 100 daltons, provides that a DP of 100 corresponds to a polymer molecular weight of about 10,000 daltons.

"DS" or "degree of substitution" refers to the average number of repeating units in a polymer chain bearing a substituent. For example, a polytbiophene-fullerene conjugate having a DS = 1 implies that substantially every thienyl unit, on average, bears a single fullerene.

"Substantially" as the term is used herein means completely or almost completely; for example, a composition that is "substantially free" of a component either has none of the component or contains such a trace amount that any relevant functional property of the composition is unaffected by the presence of the trace amount, or a compound is "substantially pure" is th ere are only negligible traces of impurities present.

By "chemically feasible" is meant a bonding arrangement or a compound where the generally understood rules of organic structure are not violated; for example a structure within a definition of a claim that would contain in certain situations a pentavalent carbon atom that would not exist in nature would be understood to not be within the claim. The structures disclosed herein, in all of their embodiments are intended to include only "chemically feasible" structures, and any recited structures that are not chemically feasible, for example in a structure shown with variable atoms or groups, are not intended to be disclosed or claimed herein.

When a substituent is specified to be an atom or atoms of specified identity, "or a bond", a configuration is referred to when the substituent is "a bond" that the groups that are immediately adjacent to the specified substituent are directly connected to each other in a chemically feasible bonding

configuration.

All chiral, diastereomeric, racemic forms of a structure are intended, unless a particular stereochemistry or isomeric form is specifically indicated. Compounds used in the present invention can include enriched or resolved optical isomers at any or all asymmetric atoms as are apparent from the depictions, at any degree of enrichment. Both racemic and diastereomeric mixtures, as well as the individual optical isomers can be isolated or synthesized so as to be substantially free of their enantiomeric or diastereomeric partners, and these are all within the scope of the invention.

In general, "substituted" refers to an organic group as defined herein in which one or more bonds to a hydrogen atom contained therein are replaced by one or more bonds to a non-hydrogen atom such as, but not limited to, a halogen (i.e., F, CI, Br, and I); an oxygen atom in groups such as hydroxyl groups, alkoxy groups, aryloxy groups, aralkyloxy groups, oxo(carbonyl) groups, carboxyl groups including carboxylic acids, carboxylates, and carboxylate esters; a sulfur atom in groups such as thiol groups, alkyl and aryl sulfide groups, sulfoxide groups, sulfone groups, sulfonyl groups, and sulfonamide groups; a nitrogen atom in groups such as amines, hydroxylamines, nitriles, nitro groups, N-oxides, hydrazides, azides, and enamines; and other heteroatoms in various other groups. Non-limiting examples of substituents J that can be bonded to a substituted carbon (or other) atom include F, CI, Br, I, OR', OC(O)N(R')₂, CN, NO, N0₂, ON0₂, azido, CF₃, OCF₃, R', O (oxo), S (thiono), C(O), S(O), methylenedioxy, ethylenedioxy, N(R')₂, SR', SOR', S0₂R, S0₂N(R')₂, S0₃R', C(O)R', C(O)C(O)R', C(O)CH₂C(O)R', C(S)R, C(O)OR, OC(O)R, C(O)N(R')₂, OC(O)N(R')₂, C(S)N(R')₂, (CH₂)_0-2N(R^,)C(O)R', (CH₂)_0-2N(R')N(R')₂,

N(R')N(R')C(Q)R', N(R')N(R^,)C(O)OR', N(R')N(R')CON(R)₂, N(R')SO₂R', N(R')S0₂N(R')₂, N(R')C(O)OR', N(R')C(O)R', N(R')C(S)R^!, N(R')C(O)N(R')₂, N(R')C(S)N(R')¾ N(COR')COR', N(OR')R', C(=NH)N(R')₂, C(O)N(OR')R, or C(=NOR')R' wherein R' can be hydrogen or a carbon-based moiety, and wherein the carbon-based moiety can itself be further substituted; for example, wherein R' can be hydrogen, alkyl, acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroarylalkyl, wherein any alkyl, acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroarylalkyl or R' can be independently mono- or multi-substituted with J; or wherein two R' groups bonded to a nitrogen atom or to adjacent nitrogen atoms can together with the nitrogen atom or atoms form a heterocyclyl, which can be mono- or independently multi-substituted with J.

When a substituent is monovalent, such as, for example, F or CI, it is bonded to the atom it is substituting by a single bond. When a substituent is more than monovalent, such as O, which is divalent, it can be bonded to the atom it is substituting by more than one bond, i.e., a divalent substituent is bonded by a double bond; for example, a C substituted with O forms a carbonyl group, C=O, which can also be written as "CO", "C(O)", or "C(=O)", wherein the C and the O are double bonded. When a carbon atom is substituted with a double-bonded oxygen (=O) group, the oxygen substituent is termed an "oxo" group. When a divalent substituent such as NR is double-bonded to a carbon atom, the resulting C(=NR) group is termed an "imino" group. When a divalent substituent such as S is double-bonded to a carbon atom, the results C(=S) group is termed a "thiocarbonyl" group.

Alternatively, a divalent substituent such as O, S, C(O), S(O), or S(O)₂ can be connected by two single bonds to two different carbon atoms. For example, O, a divalent substituent, can be bonded to each of two adjacent carbon atoms to provide an epoxide group, or the O can form a bridging ether group, termed an "oxy" group, between adjacent or non-adjacent carbon atoms, for example bridging the 1 ,4- carbons of a cyclohexyl group to form a [2.2.1]- oxabicyclo system. Further, any substituent can be bonded to a carbon or other atom by a linker, such as (CH₂)_n or (CR'2)_n wherein n is 1, 2, 3, or more, and each R' is independently selected.

C(O) and S(O)₂ groups can also be bound to one or two heteroatoms, such as nitrogen or oxygen, rather than to a carbon atom. For example, when a C(O) group is bound to one carbon and one nitrogen atom, the resulting group is called an "amide" or "carboxamide." When a C(O) group is bound to two nitrogen atoms, the functional group is termed a "urea." When a C(O) is bonded to one oxygen and one nitrogen atom, the resulting group is termed a

"carbamate" or "urethane." When a S(O)₂ group is bound to one carbon and one nitrogen atom, the resulting unit is termed a "sulfonamide." When a S(O)₂ group is bound to two nitrogen atoms, the resulting unit is termed a "sulfamate." Substituted alkyl, alkenyl, alkynyl, cycloalkyl, and cycloalkenyl groups as well as other substituted groups also include groups in which one or more bonds to a hydrogen atom are replaced by one or more bonds, including double or triple bonds, to a carbon atom, or to a heteroatom such as, but not limited to, oxygen in carbonyl (oxo), carboxyl, ester, amide, imide, urethane, and urea groups; and nitrogen in imines, hydroxyimines, oximes, hydrazones, amidmes, guanidines, and nitrites.

Substituted ring groups such as substituted cycloalkyl, aryl, heterocyclyl and heteroaryl groups also include rings and fused ring systems in which a bond to a hydrogen atom is replaced with a bond to a carbon atom. Therefore, substituted cycloalkyl, aryl, heterocyclyl and heteroaryl groups can also be substituted with alkyl, alkenyl, and alkynyl groups as defined herein.

By a "ring system" as the term is used herein is meant a moiety comprising one, two, three or more rings, which can be substituted with non-ring groups or with other ring systems, or both, which can be fully saturated, partially unsaturated, fully unsaturated, or aromatic, and when the ring system includes more than a single ring, the rings can be fused, bridging, or spirocyclic. By "spirocyclic" is meant the class of structures wherein two rings are fused at a single tetrahedral carbon atom, as is well known in the art.

As to any of the groups described herein, which contain one or more substituents, it is understood, of course, that such groups do not contain any substitution or substitution patterns which are sterically impractical and/or synthetically non-feasible. In addition, the compounds of this disclosed subject matter include all stereochemical isom ers arising from th e substituti on of these compounds.

Selected substituents within the compounds described herein are present to a recursive degree. In this context, "recursive substituent" means that a substituent may recite another instance of itself or of another substituent that i tself recites the first substi tuent. Because of the recursive nature of such substituents, theoretically, a large number may be present in any given claim. One of ordinary skill in the art of medicinal chemistry and organic chemistry understands that the total number of such substituents is reasonably limited by the desired properties of the compound intended. Such properties include, by way of example and not limitation, physical properties such as molecular weight, solubility or log P, application properties such as acti vity against the intended target, and practical properties such as ease of synthesis.

Recursive substituents are an intended aspect of the disclosed subject matter. One of ordinary skill in the art of medicinal and organic chemistry understands the versatility of such substituents. To the degree that recursive substituents are present in a claim of the disclosed subject matter, the total number should be determined as set forth above.

Alkyl groups include straight chain and branched alkyl groups and cycloalkyl groups having from 1 to about 20 carbon atoms, and typically from 1 to 12 carbons or, in some embodiments, from 1 to 8 carbon atoms. Examples of straight chain alkyl groups include those with from 1 to 8 carbon atoms such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Examples of branched alkyl groups include, but are not limited to, isopropyl, iso-butyl, sec-butyl, t-butyl, neopentyl, isopentyl, and 2,2-dimethylpropyl groups. As used herein, the term "alkyl" encompasses n-alkyl, isoalkyl, and anteisoalkyl groups as well as other branched chain forms of alkyl.

Representative substituted alkyl groups can be substituted one or more times with any of the groups listed above, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups.

Cycloalkyl groups are cyclic alkyl groups such as, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. In some embodiments, the cycloalkyl group can have 3 to about 8-12 ring members, whereas in other embodiments the number of ring carbon atoms range from 3 to 4, 5, 6, or 7. Cycloalkyl groups further include polycyclic cycloalkyl groups such as, but not limited to, norbornyl, adamantyl, bornyl, camphenyl, isocamphenyl, and carenyl groups, and fused rings such as, but not limited to, decalinyl, and the like. Cycloalkyl groups also include rings that are substituted with straight or branched chain alkyl groups as defined above.

Representative substituted cycloalkyl groups can be mono-substituted or substituted more than once, such as, but not limited to, 2,2-, 2,3-, 2,4- 2,5- or 2,6-disubstituted cyclohexyl groups or mono-, di- or tri-substituted norbornyl or cycloheptyl groups, which can be substituted with, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups. The term

"cycloalkenyl" alone or in combination denotes a cyclic alkenyl group. The terms "carbocyclic," "carbocyclyl," and "carbocycle" denote a ring structure wherein the atoms of the ring are carbon, such as a cycloalkyl group or an aryl group. In some embodiments, the carbocycle has 3 to 8 ring members, whereas in other embodiments the number of ring carbon atoms is 4, 5, 6, or 7. Unless specifically indicated to the contrary, the carbocyclic ring can be substituted with as many as N-l substituents wherein N is the size of the carbocyclic ring with, for example, alkyl, alkenyl, alkynyl, amino, aryl, hydroxy, cyano, carboxy, heteroaryl, heterocyclyl, nitro, thio, alkoxy, and halogen groups, or other groups as are listed above. A carbocyclyl ring can be a cycloalkyl ring, a cycloalkenyl ring, or an aryl ring. A carbocyclyl can be monocyclic or polycyclic, and if polycyclic each ring can be independently be a cycloalkyl ring, a cycloalkenyl ring, or an aryl ring.

(Cycloalkyl)alkyl groups, also denoted cycloalkylalkyl, are alkyl groups as defined above in which a hydrogen or carbon bond of the alkyl group is replaced with a bond to a cycloalkyl group as defined above.

Alkenyl groups include straight and branched chain and cyclic alkyl groups as defined above, except that at least one double bond exists between two carbon atoms. Thus, alkenyl groups have from 2 to about 20 carbon atoms, and typically from 2 to 12 carbons or, in some embodiments, from 2 to 8 carbon atoms. Examples include, but are not limited to vinyl, -CH=CH(CH₃),

-CH=C(CH₃)₂, -C(CH₃)=CH₂, -C(CH₃)=CH(CH₃), -C(CH₂CH₃)=CH₂, cyclohexenyl, cyclopentenyl, cyclohexadienyl, butadienyl, pentadienyl, and hexadienyl among others.

Cycloalkenyl groups include cycloalkyl groups having at least one double bond between 2 carbons. Thus for example, cycloalkenyl groups include but are not limited to cyclohexenyl, cyclopentenyl, and cyclohexadienyl groups. Cycloalkenyl groups can have from 3 to about 8-12 ring members, whereas in other embodiments the number of ring carbon atoms range from 3 to 5, 6, or 7. Cycloalkyl groups further include polycyclic cycloalkyl groups such as, but not limited to, norbornyl, adamantyl, bornyl, camphenyl, isocamphenyl, and carenyl groups, and fused rings such as, but not limited to, decalinyl, and the like, provided they include at least one double bond within a ring. Cycloalkenyl groups also include rings that are substituted with straight or branched chain alkyl groups as defined above. (Cycloalkenyl)alkyl groups are alkyl groups as defined above in which a hydrogen or carbon bond of the alkyl group is replaced with a bond to a cycloalkenyl group as defined above.

Alkynyl groups include straight and branched chain alkyl groups, except that at least one triple bond exists between two carbon atoms. Thus, alkynyl groups have from 2 to about 20 carbon atoms, and typically from 2 to 12 carbons or, in some embodiments, from 2 to 8 carbon atoms. Examples include, but are not limited to -C=CH, -C=C(CH₃), -C=C(CH₂CH₃), -CH₂C=CH,

-CH₂OC(CH₃), and -CH₂C=C(CH₂CH₃) among others.

The term "heteroalkyl" by itself or in combination with another term means, unless otherwise stated, a stable straight or branched chain alkyl group consisting of the stated number of carbon atoms and one or two heteroatoms selected from the group consisting of O, N, and S, and wherein the nitrogen and sulfur atoms may be optionally oxidized and the nitrogen heteroatom may be optionally quaternized. The heteroatom(s) may be placed at any position of the heteroalkyl group, including between the rest of the heteroalkyl group and the fragment to which it is attached, as well as attached to the most distal carbon atom in the heteroalkyl group. Examples include: -0-CH₂-CH₂-CH₃,

-CH₂-CH₂CH₂-OH, -CH₂-CH₂-NH-CH₃, -CH₂-S-CH₂-CH₃,

-CH₂CH₂-S(=O)-CH₃, and -CH₂CH₂-0-CH₂CH₂-0-CH₃. Up to two heteroatoms may be consecutive, such as, for example, -CII₂-NH-OCII₃, or -- CH₂-CH₂-S-S-CH₃.

A "cycloheteroalkyl" ring is a cycloalkyl ring containing at least one heteroatom. A cycloheteroalkyl ring can also be termed a "heterocyclyl," described below.

The term "heteroalkenyl" by itself or in combination with another term means, unless otherwise stated, a stable straight or branched chain

monounsaturated or di-unsaturated hydrocarbon group consisting of the stated number of carbon atoms and one or two heteroatoms selected from the group consisting of O, N, and S, and wherein the nitrogen and sulfur atoms may optionally be oxidized and the nitrogen heteroatom may optionally be quaternized. Up to two heteroatoms may be placed consecutively. Examples include -CH=CH-0-CH₃, -CH=CH-CH,-OH, -CH₂-CH=N-OCH₃,

-CH=CH-N(CH₃)-CH3, -CH₂-CH=CH-CH₂-SH, and and -CH=CH-0-CH₂CH₂- Aryl groups are cyclic aromatic hydrocarbons that do not contain heteroatoms in the ring. Thus aryl groups include, but are not limited to, phenyl, azulenyl, heptalenyl, biphenyl, indacenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl, naphthacenyl, chrysenyl, biphenylenyl, anthracenyl, and naphthyl groups. In some embodiments, aryl groups contain about 6 to about 14 carbons in the ring portions of the groups. Aryl groups can be unsubstituted or substituted, as defined above. Representative substituted aryl groups can be mono-substituted or substituted more than once, such as, but not limited to, 2-, 3-, 4-, 5-, or 6-substituted phenyl or 2-8 substituted naphthyl groups, which can be substituted with carbon or non-carbon groups such as those listed above.

Aralkyl groups are alkyl groups as defined above in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to an aryl group as defined above. Representative aralkyl groups include benzyl and phenylethyl groups and fused (cycloalkylaryl)alkyl groups such as 4-ethyl-indanyl.

Aralkenyl group are alkenyl groups as defined above in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to an aryl group as defined above.

Heterocyclyl groups or the term "heterocyclyl" includes aromatic and non-aromatic ring compounds containing 3 or more ring members, of which, one or more is a heteroatom such as, but not limited to, N, O, and S. Thus a heterocyclyl can be a cycloheteroalkyl, or a heteroaryl, or if polycyclic, any combination thereof. In some embodiments, heterocyclyl groups include 3 to about 20 ring members, whereas other such groups have 3 to about 15 ring members. A heterocyclyl group designated as a C2-heterocyclyl can be a 5 -ring with two carbon atoms and three heteroatoms, a 6-ring wi th two carbon atoms and four heteroatoms and so forth. Likewise a C4-heterocyclyl can be a 5 -ring with one heteroatom, a 6-ring with two heteroatoms, and so forth. The number of carbon atoms plus the number of heteroatoms sums up to equal the total number of ring atoms. A heterocyclyl ring can also include one or more double bonds. A heteroaryl ring is an embodiment of a heterocyclyl group. The phrase "heterocyclyl group" includes fused ring species including those comprising fused aromatic and non-aromatic groups. For example, a dioxolanyl ring and a benzdioxolanyl ring system (methylenedioxyphenyl ring system) are both heterocyclyl groups within the meaning herein. The phrase also includes polycyclic ring systems containing a heteroatom such as, but not limited to, quinuclidyl. Heterocyclyl groups can be unsubstituted, or can be substituted as discussed above. Heterocyclyl groups include, but are not limited to, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, pyrrolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridinyl, thiophenyl,

benzothiophenyl, benzofuranyl, dihydrobenzofuranyl, indolyl, dihydroindolyl, azaindolyl, indazolyl, benzimidazolyl, azabenzimidazolyl, benzoxazolyl, benzothiazolyl, benzothiadiazolyl, imidazopyridinyl, isoxazolopyridinyl, thianaphthalenyl, purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl,

isoquinolinyl, tetrahydroquinolinyl, quinoxalinyl, and quinazolinyl groups. Representative substituted heterocyclyl groups can be mono-substituted or substituted more than once, such as, but not limited to, piperidinyl or quinolinyl groups, which are 2-, 3-, 4-, 5-, or 6-substituted, or disubstituted with groups such as those listed above.

Heteroaryl groups are aromatic ring compounds containing 5 or more ring members, of which, one or more is a heteroatom such as, but not limited to, N, O, and S; for instance, heteroaryl rings can have 5 to about 8-12 ring members. A heteroaryl group is a variety of a heterocyclyl group that possesses an aromatic electronic structure. A heteroaryl group designated as a Cj- heteroaryl can be a 5 -ring with two carbon atoms and three heteroatoms, a 6-ring with two carbon atoms and four heteroatoms and so forth. Likewise a C₄- heteroaryl can be a 5 -ring with one heteroatom, a 6-ring with two heteroatoms, and so forth. The number of carbon atoms plus the number of heteroatoms sums up to equal the total number of ring atoms. Heteroaryl groups include, but are not limited to, groups such as pyrrolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridinyl, thiophenyl, benzothiophenyl, benzofuranyl, indolyl, azaindolyl, indazolyl, benzimidazolyl, azabenzimidazolyl, benzoxazolyl, benzothiazolyl, benzothiadiazolyl, imidazopyridinyl, isoxazolopyridinyl, thianaphthalenyl, purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl,

isoquinolinyl, tetrahydroquinolinyl, quinoxalinyl, and quinazolinyl groups.

Heteroaryl groups can be unsubstituted, or can be substituted with groups as is discussed above. Representative substituted heteroaryl groups can be substituted one or more times with groups such as those listed above. Additional examples of aryl and heteroaryl groups include but are not limited to phenyl, biphenyl, indenyl, naphthyl (1-naphthyl, 2-naphthyl), N- hydroxytetrazolyl, N-hydroxytriazolyl, N-hydroxyimidazolyl, anthracenyl (1- anthracenyl, 2-antbracenyl, 3-anthracenyl), thiophenyl (2-thienyl, 3-thienyl), furyl (2-furyl, 3 -fury 1) , indolyl, oxadiazolyl, isoxazolyl, quinazolinyl, fluorenyl, xanthenyl, isoindanyl, benzhydryl, acridinyl, thiazolyl, pyrrolyl (2-pyrrolyl), pyrazolyl (3-pyrazolyl), imidazolyl (1-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5- imidazolyl), triazolyl ( 1 ,2,3-triazol- 1 -yl, 1,2,3-triazol-2-yl 1,2,3-triazol-4-yl, 1,2,4-triazol-3-yl), oxazolyl (2-oxazolyl, 4-oxazolyl, 5-oxazolyl), thiazolyl (2- thiazolyl, 4-thiazolyl, 5-thiazolyl), pyridyl (2-pyridyl, 3-pyridyl, 4-pyridyl), pyrimidinyl (2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl), pyrazinyl, pyridazinyl (3- pyridazinyl, 4-pyridazinyl, 5-pyridazinyl), quinolyl (2- quinolyl, 3-quinolyl, 4-quinolyl, 5 -quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl), isoquinolyl (1-isoquinolyl, 3-isoqumolyl, 4-isoquinolyl, 5-isoquinolyl, 6- isoquinolyl, 7-isoquinolyl, 8-isoquinolyl), benzo[b]furanyl (2-benzo[b]furanyl, 3 -benzo [b] furany 1, 4-benzo [b] furanyl, 5-benzo[b]furanyl, 6-benzo [b] furanyl, 7- benzo[b]furanyl), 2 ,3 -dihydro-benzo [b] furanyl (2-(2,3-dihydro- benzo[b]furanyl), 3-(2,3-dihydro-benzo[b]furanyl), 4-(2,3-dihydro- benzo[b] furanyl), 5-(2,3-dihydro-benzo[b]furanyl), 6-(2,3-dihydro- benzo[b] furanyl), 7-(2 ,3-dihydro-benzo [b] furanyl), benzo [b]thiophenyl (2- benzo [b]thiophenyl, 3 -benzo [b] thiophenyl, 4-benzo [b]thiophenyl ,

5 -benzo [b]thiophenyl, 6-benzo [b] thiophenyl, 7-benzo [b ]thiophenyl),

2,3 -dihydro-benzo [bjthiophenyl, (2-(2,3 -dihydro-benzo [bjthiophenyl), 3 -(2,3 - dihydro-benzo [b]thiophenyl), 4-(2,3-dihydro-benzo[b]thiophenyl), 5-(2,3- dihydro-benzo[b]thiophenyl), 6-(2,3-dihydro-benzo[b]thiophenyl), 7-(2,3- dihydro-benzo[b] thiophenyl), indolyl (1 -indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6-indolyl, 7-indolyl), indazole (1-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl), benzimidazolyl ( 1 -benzimidazoly 1, 2-benzimidazolyl, 4-benzimidazolyl, 5-benzimidazolyl, 6-benzimidazolyl, 7-benzimidazolyl, 8-benzimidazolyl), benzoxazolyl (1-benzoxazolyl, 2- benzoxazolyl), benzothiazoiyl ( 1 -benzothiazoly 1, 2-benzothiazoiyl, 4- benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl), carbazolyl ( 1 -carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl),

5H-dibenz[b,fjazepine (5H-dibenz[b,fJazepin- 1 -yl, 5H-dibenz[b,fJazepine-2-yl, 5II-dibenz[b,f]azepine-3-yl, 5H-dibenz[b,f]azepine-4-yl, 5II-dibenz[b,f]azepine- 5-yl), 10,1 l-dihydro-5H-dibenz[b,f]azepine ( 10,11 -dihydro-5H- dibenz[b,fjazepine-1-yl, 10,1 l-dihydro-5H-dibenz[b,fjazepme-2-yl, 10,1 1- dihydro-5H-dibenz[b,f]azepine-3-yl, 10, 11 -dihydro-5H-dibenz[b,fjazepine-4-yl, 10,1 1 -dihydro-5H-dibenz[b,f]azepine-5-yl), and the like.

Heterocyclylalkyl groups are alkyl groups as defined above in which a hydrogen or carbon bond of an alkyl group as defined above is replaced with a bond to a heterocyclyl group as defined above. Representative heterocyclyl alkyl groups include, but are not limited to, furan-2-yl methyl, furan-3-yl methyl, pyridine-3-yl methyl, tetrahydrofuran-2-yl ethyl, and indol-2-yl propyl.

Heteroarylalkyl groups are alkyl groups as defined above in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to a heteroaryl group as defined above.

The term "alkoxy" refers to an oxygen atom connected to an alkyl group, including a cycloalkyl group, as are defined above. Examples of linear alkoxy groups include but are not limited to methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, and the like. Examples of branched alkoxy include but are not limited to isopropoxy, sec-butoxy, tert-butoxy, isopentyloxy, isohexyloxy, and the like. Examples of cyclic alkoxy include but are not limited to cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and the like. An alkoxy group can include one to about 12-20 carbon atoms bonded to the oxygen atom, and can further include double or triple bonds, and can also include heteroatoms. For example, an allyloxy group is an alkoxy group within the meaning herein. A methoxyethoxy group is also an alkoxy group within the meaning herein, as is a methylenedioxy group in a context where two adjacent atoms of a structures are substituted therewith.

The terms "halo" or "halogen" or "halide" by themselves or as part of another substituent mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom, preferably, fluorine, chlorine, or bromine.

A "haloalkyl" group includes mono-halo alkyl groups, poly-halo alkyl groups wherein all halo atoms can be the same or different, and per-halo alkyl groups, wherein all hydrogen atoms are replaced by halogen atoms, such as fluoro. Examples of haloalkyl include trifluoromethyl, 1 , 1 -dichloroethyl, 1,2- dichloroethyl, 1 ,3-dibromo-3,3-difluoropropyl, perfluorobutyl, and the like. A "haloalkoxy" group includes mono-halo alkoxy groups, poly-halo alkoxy groups wherein all halo atoms can be the same or different, and per-halo alkoxy groups, wherein all hydrogen atoms are replaced by halogen atoms, such as fluoro. Examples of haloalkoxy include trifluoromethoxy, 1,1 - dichloroethoxy, 1 ,2-dichloroethoxy, 1 ,3-dibromo-3,3-difluoropropoxy, perfluorobutoxy, and the like.

The term "(C_x-C_y)perfluoroalkyl," wherein x < y, means an alkyl group with a minimum of x carbon atoms and a maximum of y carbon atoms, wherein all hydrogen atoms are replaced by fluorine atoms. Preferred is

-(C₁-C₆)perfIuoroalkyl, more preferred is -(C₁-C₃)perfluoroalkyl, most preferred is -CF₃.

The term "(Cx-Cy)perfluoroalkylene," wherein x < y, means an alkyl group with a minimum of x carbon atoms and a maximum of y carbon atoms, wherein all hydrogen atoms are replaced by fluorine atoms. Preferred is -(C₁-C₆)perfluoroalkylene, more preferred is -(Ci-Cj)perfluoroalkylene, most preferred is -CF₂-.

The terms "aryloxy" and "arylalkoxy" refer to, respectively, an aryl group bonded to an oxygen atom and an aralkyl group bonded to the oxygen atom at the alkyl moiety. Examples include but are not limited to phenoxy, naphthyloxy, and benzyloxy.

An "acyl" group as the term is used herein refers to a group containing a carbonyl moiety wherein the group is bonded via the carbonyl carbon atom. The carbonyl carbon atom is also bonded to another carbon atom, which can be part of an alkyl, aryl, aralkyl cycloalkyl, cycloalkylalkyl, heterocyclyl,

heterocyclylalkyl, heteroaryl, heteroarylalkyl group or the like. In the special case wherein the carbonyl carbon atom is bonded to a hydrogen, the group is a "formyl" group, an acyl group as the term is defined herein. An acyl group can include 0 to about 12-20 additional carbon atoms bonded to the carbonyl group. An acyl group can include double or triple bonds within the meaning herein. An acryloyl group is an example of an acyl group. An acyl group can also include heteroatoms within the meaning here. A nicotinoyl group (pyridyl-3 -carbonyl) group is an example of an acyl group within the meaning herein. Other examples include acetyl, benzoyl, phenylacetyl, pyridylacetyl, cinnamoyl, and acryloyl groups and the like. When the group containing the carbon atom that is bonded to the carbonyl carbon atom contains a halogen, the group is termed a

"haloacyl" group. An example is a trifluoroacetyl group.

The term "amine" includes primary, secondary, and tertiary amines having, e.g., the formula N(group)3 wherein each group can independently be II or non-H, such as alkyl, aryl, and the like. Amines include but are not limited to

R-NH₂, for example, alkylamines, arylamines, alkylarylamines; R₂NH wherein each R is independently selected, such as dialkylamines, diarylamines, aralkylamines, heterocyclylamines and the like; and R3N wherein each R is independently selected, such as trialkylamines, dialkylarylamines,

alkyidiarylamines, triarylamines, and the like. The term "amine" also includes ammonium ions as used herein.

An "amino" group is a substituent of the form -NII2, -NI IR, -NR2, -NR./, wherein each R is independently selected, and protonated forms of each, except for -NR3⁺ , which cannot be protonated. Accordingly, any compound substituted with an amino group can be viewed as an amine. An "amino group" within the meaning herein can be a primary, secondary, tertiary or quaternary amino group.

An "alkylamino" group includes a monoalkylamino, dialkylamino, and trialkylamino group.

An "ammonium" ion includes the unsubstituted ammonium ion NIL₄ ⁺, but unless otherwise specified, it also includes any protonated or quaternarized forms of amines. Thus, trimethylammonium hydrochloride and

tetramethylammonium chloride are both ammonium ions, and amines, within the meaning herein.

The term "amide" (or "amido") includes C- and N-amide groups, i,e,, -C(O)NR₂, and -NRC(O)R groups, respectively. Amide groups therefore include but are not limited to primary carboxamide groups (-C(O)NIl2) and formamide groups (-NHC(O)H). A "carboxamido" group is a group of the formula C(O)NR₂, wherein R can be H, alkyl, aryl, etc.

The term "azido" refers to an N3 group. An "azide" can be an organic azide or can be a salt of the azide (N₃-) anion. The term "nitro" refers to an N0₂ group bonded to an organic moiety. The term "nitroso" refers to an NO group bonded to an organic moiety. The term nitrate refers to an ONO2 group bonded to an organic moiety or to a salt of the nitrate (NO3 ) anion. The term "urethane" ("carbamoyl" or "carbamyl") includes N- and O- urethane groups, i.e., -NRC(O)OR and -OC(O)NR₂ groups, respectively.

The term "sulfonamide" (or "suifonamido") includes S- and N- sulfonamide groups, i.e., -SO2NR2 and -NRSO2R groups, respectively.

Sulfonamide groups therefore include but are not limited to sulfamoyl groups (- SO2NH2). An organosulfur stiructure represented by the formula -S(O)(NR)- is understood to refer to a sulfoximine, wherein both the oxygen and the nitrogen atoms are bonded to the sulfur atom, which is also bonded to two carbon atoms.

The term "amidine" or "amidino" includes groups of the formula -C(NR)NR-2. Typically, an amidino group is -C(NH)NH2.

The term "guanidine" or "guanidino" includes groups of the formula -NRC(NR)NR₂. Typically, a guanidino group is -NIIC(NII)NII₂.

In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group. For example, if X is described as selected from the group consisting of bromine, chlorine, and iodine, claims for X being bromine and claims for X being bromine and chlorine are fully described. Moreover, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any combination of individual members or subgroups of members of Markush groups. Thus, for example, if X is described as selected from the group consisting of bromine, chlorine, and iodine, and Y is described as selected from the group consisting of methyl, ethyl, and propyl, claims for X being bromine and Y being methyl are fully described.

If a value of a variable that is necessarily an integer, e.g., the number of carbon atoms in an alkyl group or the number of substituents on a ring, is described as a range, e.g., 0-4, what is meant is that the value can be any integer between 0 and 4 inclusive, i.e., 0, 1, 2, 3, or 4.

In various embodiments, the compound or set of compounds, such as are used in the inventive methods, can be any one of any of the combinations and/or sub- combinations of the above- listed embodiments.

In various embodiments, a compound as shown in any of the Examples, or among the exemplary compounds, is provided. Provisos may apply to any of the disclosed categories or embodiments wherein any one or more of the other above disclosed embodiments or species may be excluded from such categories or embodiments. Detailed Description

The invention is directed, in various embodiments, to compositions comprising polythiophene polymers substituted along the polymer backbone with one or more pendant groups comprising a linker bearing a fullerene. In various embodiments, compositions of the invention can be prepared by coupling of polythiophene polymers, wherein all, or at least some, of the thienyl repeating units within the polymer chain, bear a linker precursor group that can react with a suitable fullerene derivative, or with an underivatized fullerene, to yield a covalently or ionically coupled fullerene-polythiophene conjugate.

In various embodiments, the invention provides a composition for photovoltaic electrical generation, comprising a polythiophene polymer having thienyl repeating units, wherein at least some of the thienyl repeating units not disposed at a polymer chain terminus are covalently or ionically bonded via respective linkers to respective fullerene groups. In a composition of the invention, fullerene groups are bonded to at least some of the internal thienyl repeating units within the chain, and are not to any substantial degree disposed at polymer chain termini. A polythiophene chain can have more than a single fullerene unit bonded thereto. Within a bulk sample of a composition of the invention, some individual polymer molecules may not bear a fullerene group, but most of the individual polymer molecules bear at least one fullerene group and may bear more.

Polythiophenes are a well known group of polymer that incorporate thiophene rings (thienyls) as repeating units in the polymer. Thienyl groups are directly linked to each other such that the polymer comprises conjugated unsaturations. Polythiophenes can be random, i.e., wherein the positions on each thienyl unit linking it to adjacent thienyl units are random, or can be

regioregular, i.e., wherein the positions of bonding of each thienyl unit to its neighbors is substantially uniform throughout the polymer molecule.

In various embodiments, the composition of the invention comprises a regioregular polythiophene polymer. For example, the polythiophene polymer can be a 2,5 -polythiophene, wherein the bonds linking the thienyl repeating units are attached to the carbon atoms adjacent to the thienyl sulfur atom.

In a polythiophene polymer, for each thienyl repeating unit there are four carbon atoms available for bonding in addition to the sulfur atom, which is fully substituted. Accordingly, in a regioregular polythiophene such as a 2,5- polythiophene there are two additional positions, the 3- and 4-positions, available for substitution. Substitution on one or both of these positions not involved in formation of the polymer backbone pro vides groups that are pendant from the polymer backbone. For example, the polythiophene polymer can comprise monosubstituted thienyl repeating units, such as 3-substituted thienyl units. In various embodiments, the composition of the invention is a regioregular I IT-2,5 -polythiophene, comprising monosubstituted thienyl repeating units, wherein the composition is of formula (I)

wherein each independently selected X comprises a linker precursor group comprising a reactive group;

X' is a linker bonded covalently to at least one of the monosubstituted thienyl repeating units wherein X' can comprise covalent bonds, ionic bonds, or both;

"FLR" is a fullerene bonded covalently or ionically via X' to the regioregular polythiophene;

n and n' are each independently about 3 to about 10,000; and each star * indicates a continuing chain with a terminal atom, each chain optionally bearing additional fullerenes linked to the regioregular polythiophene by linker X'.

As described above, formula (I) depicts a 2,5-head-to-tail regioregular 3- monsubstituted polythiophene, which contains from about 10 to about 2,000 repeating units (i.e., of molecular weight about 1,000 to about 200,000); for example, the polymer can include about 50 to about 2,000 repeating units (i.e., of molecular weight about 5,000 to about 200,000), or can include about 100 to about 200 repeating units (i.e., of molecular weight about 10,000 to about 20,000). A bulk sample of a polythiophene of the invention can contain a distribution of individual polymer molecular weights, having a weight average molecular weight, and a polydispersity index. See, for example, U.S. Pat. No. 7572880 and U.S. published application Nos. 2010/0004423 and 2010/0311879 by the inventor herein.

Each thienyl repeating unit comprises a linker precursor group, X, which is for reaction with a suitable fullerene, such that for at least some of the thienyl repeating units, a fullerene-linker conjugate is obtained, wherein the fullerene is bonded either covalently or ionically via the linker X' to the polythiophene backbone.

More specifically, as described above, the fullerene can be a C61- fulierene, wherein a fused cyclopropano group is bonded to the C60- fullerene nucleus, such as can be prepared by a carbene insertion reaction with the C60- fullerene, or analogously with a C70-fullerene to produce a C71 -fullerene derivative. Accordingly, in various embodiments, the composition of the invention can comprise a polythiophene- fullerene conjugate of formula

wherein R is H, alkyl, or aryl, any alkyl or aryl being optionally substituted; n and n' are each independently about 3 to about 10,000; and

X' is a linker resulting from covalent or ionic bond formation between the linker precursor group of X and a suitable fullerene reactant. As described above, PCBA is a commercially available fullerene derivative that can be prepared by reaction of an a-diazophenylpentanoic acid or ester with C60- fullerene. The pendant acid or ester group of the C61 -fullerene PCBA is available for further conversions in various organic reactions that are compatible with the C60-fullerene nucleus.

For example, a polythiophene-fullerene conjugate can be of formula

wherein the variables m, n, and n' are as described above, wherein Y can include an oxygen atom (forming an ester linkage) or a nitrogen atom (forming an amide linkage) or a carboxylate group (forming an anhydride linkage), wherein Y also includes as a substructure those components of the linker precursor group X that have been incorporated in the course of the coupling reaction, e.g., alkyl chains, and the like. In this example, the fragment

-CH₂(CH₂)mCH₂C(=O)Y- makes up the linker X' of the preceding form ula.

Alternatively, the composition of the invention can be of formula

wherein the carboxyl group of PCBA has been reduced to a carbinol, such as by the action of diborane, which can then be coupled with a suitable X group to yield either an ether, wherein the carbinol oxygen is included, or an alkyl chain, wherein the carbinol hydroxyl group has been activated and displaced by a nucleophile, to form linker Y.

Alternatively, the composition of the invention can be of formula

wherein the linker group is formed via a Wittig type condensation or its equivalent (e.g., HWE reaction) of a carboxaldehyde group on one of the fullerene or the polythiophene linker precursor group and a phosphonium (or phosphorate) on the other reactant.

Alternatively, the composition of the invention can be of formula

wherein the coupling of the fullerene and the polythiophene is carried out by condensation of an X group organometallie agent such as an organolithium,

Gri guard, or Reformatsky reagent and a fullerene carboxyaldehyde, such as can itself be prepared from gentle oxidation of the fullerene carbinol described above. More specifically, in various embodiments, the invention provides the above structure wherein

m is 0 to about 12;

n and n' are each independently about 3 to about 10,000; and

X is a linker precursor group;

Y is (CH₂)_r, (CH₂)_rCHOH(CH₂)_r, (CH₂)_rNR¹(CH₂)_r, (CH₂)_r 0(CH₂)_r, (CH₂)_r S(O)_q(CH₂)_r, or (CH₂)_r S(O)_qNR'(CH₂)_r, wherein each independently selected r is 0 to about 6, q is 0, 1, or 2, and R¹ is H or alkyl.

In various embodiments, the composition can be any of the above structures wherein X comprises a optionally substituted (CI -CI 2) alkylene chain optionally further comprising unsaturation, cyclic groups, and heteroatoms selected from O, NR, and S, the alkylene bearing a reactive group or derivative thereof. For example, the reactive group can be an acid, an ester, a hydroxyl, an amino, or a carbonyl group.

In various embodiments, linker precursor group X can comprise a (Cl-

C12) alkylene chain, terminally substituted with CO2R¹ or COR¹, OH, halo, or NHR¹ wherein R⁵ is H or alkyl.

In various embodiments, the linker X' when formed can comprise an ester, an amide, an anhydride, an alkylation product, or an olefination product. More specifically, X' can comprise an alkylene chain in which is optionally disposed an ester, an amide, an anhydride, a double bond, or a carbinol group.

In various embodiments, the composition of the invention can be of formula

wherein m = 2 and Y is NR(CII₂)_r, 0(CH₂)_r, OC(-0)(CII₂)_r, or (CH₂)_r, and *, n and n' are as described above. A compound of this type can be prepared as described above, via coupling suitable fullerene carboxylate derivatives with alcohols, amines, carboxylic acids, and metallated allcyls, to yield esters, amides, anhydrides, and ketones, respectively.

Alternatively, the composition of the invention can be of formula

wherein m = 2 and Y is (CH₂)_r, or CH₂C(=O)(CH₂)_r, and *, n and n' are as described above. Compounds of this type can be prepared as described above by condensation of a fullerene carboxaldehyde derivative and an organometallic group of X.

Alternatively, in other embodiments, the composition can be of formula

or of formula

wherein R² is alkyl, and the other variables are as described above. Compounds of this type can be prepared by the formation of an anion adjacent to the carboxylate ester (or ketoester) on the linker precursor group X and a suitably substituted fullerene bearing a leaving group for alkylation by the anionic nucleophilic reactant.

In other embodiments, the linker bonding the fullerene and the polythiophene backbone can comprise at least one ionic bond, i.e., a salt bond, such as between a canonic group and an anionic group, such as in group X' of the formula

wherein FLR is a fullerene and

X' is a linker formed from linker precursor group X and a suitable group on the fullerene derivative. For example, the linker can comprise a bond between a cationic quaternary ammonium ion and an anionic carboxylate or sulfonate ion.

In various embodiments, the cationic ion is comprised by a cationic fullerene derivative, such as a compound of formula

wherein m and m' are each independently 0 to about 12. These exemplary compounds are an ester and an ether, respectively, of choline or a homolog thereof and PCBA or PCByl-OH, as described above.

Alternatively, the cationic fuller ene derivative can be a compound of formula

wherein each R is independently selected from the set consisting of hydrogen, alkyl, and aryl, or two R¹ groups together with the nitrogen atom to which they are bonded form a 3-8 membered heterocyclyl, optionally substituted, and optionally further comprising 1-3 addition heteroatoms selected from O, NR.', and S(O)_q wherein q is 0, 1 , or 2. Compounds of this type can be prepared as detailed in the reference noted above.

Combination of cationic fuller ene derivatives with anionic

polythiophenes, such as polythiophenes bearing carboxylate or sulfonate groups on linker precursor groups thereof, can provide an ionically-linker fullerene- polythiophene conjugate of the invention.

In various embodiments, the invention provides a method of preparing a composition of the invention, comprising contacting a polythiophene polymer bearing a linker precursor group and a fullerene suitable to react with the linker precursor group to form a polythiophene-linker-fullerene material. For example, in various embodiments, the linker precursor group comprises a carbene- generating moiety such as a diazo group, a ketene, or the like, and the fullerene is an underivatized fullerene, such that carbene insertion of the polythiophene linker precursor into a bond of C60-fullerene takes place.

In other embodiments, reactive groups on the linker precursor groups of the polythiophene can react with suitable functional groups of a fullerene derivative. For instance, the linker precursor group can comprise a nucleophilic group, and the fullerene can be a derivatized fullerene comprising an electrophilic group. Alternatively, the linker precursor group can comprise a electrophilic group, and the fullerene can be a derivatized fullerene comprising an nucleophilic group.

In embodiments wherein the fullerene comprises an electrophilic reactive group, the derivatized fullerene can be a fullerene carboxylic acid, carboxylic ester, or carboxaldehyde. For example, PCBA, which is a known compound and has been commercially available, can be used in free acid or ester form, or can be reduced to a carboxaldehyde form, such as by full reducing to a carbinol with diborane and subsequent gentle re-oxidation such as with DCC/DMSO, NCS/DMS, Cr03/pyridine, Dess-Martin periodinane, or the like.

In other embodiments, the derivatized fullerene can be a fullerene alkyl halide or alkyl sulfonate ester. Such compounds can be prepared from the fullerene carbinol described above, by conversion using standard reagents such as POCI3 for halogenation and mesyl chloride for sulfonate ester formation.

When the fullerene comprises the electrophilic component of the coupling reaction, the polythiophene linker precursor group can comprise a nucleophilic group such a hydroxyl, amino, thiol, carboxylic acid group, organolithium group, Grignard reagent, or Reformatsky reagent, that can couple to form a covalent linker group.

Alternatively, the polythiophene can comprise the electrophilic component, such as a carboxylic acid, carboxylic ester, or carboxaldehyde. Such groups can be obtained through the catalyzed coupling reactions of suitably substituted 2,5-dibromothiophenes, e.g., bearing a protected carboxylate or carboxaldehyde group on a 3 -alkyl substituent. See, for example, U.S. Pat. No. 7572880 and U.S. published application Nos. 2010/0004423 and 2010/0311879 by the inventor herein. Alternatively, the linker precursor group of the polythiophene can comprise an alkyl halide or alkyl sulfonate ester. Derivatized polymers of this type can either be prepared by polymerization of a suitably substituted 2,5-dibromothiophene, as described above, or by conversion of substituent groups present in the polymeric form, such as by reduction of the carboxaldehyde to a carbinol, e.g., with sodium cyanoborohydride, followed by activation to a halide or sulfonate as described above.

When the poiythiophene bears the electrophilic group, the fullerene derivative can bear a

nucleophilic group such as a hydroxy 1, amino, thiol, carboxylic acid group, organolithium group, Grignard reagent, or Reformatsky reagent.

Or, in various embodiments of methods of preparation of compositions of the invention, one of the linker precursor group and the derivatized fullerene can comprise a carboxaldehyde or ketone group, and the other can comprise a phosphonium ylide, a a-phosphonyl carbanion, an organolithium reagent, a Grignard reagent, or a Reformasky reagent. Coupling then occurs via a Wittig reaction, a HWE reaction, or addition of the organometallic reagent to the carbonyl, respectively.

More specifically, the derivatized fullerene can be PCBA or PCBM, and the linker precursor group of the poiythiophene can comprise a carbinol group, an amino group, or a carboxylic acid group, resulting in formation of an ester, an amide, or an anhydride, respectively, such as when the poiythiophene is a 2,5- HT-regioregular poiythiophene 3 -substituted with a hydroxyalkyl, aminoalkyl, or alkylcarboxylate group.

In other embodiments, an ionic bond is formed in the creation of the linker group. For example, one of the poiythiophene linker precursor group and the fullerene can comprise a cationic group, and the other can comprise an anionic group, as described above. For example, the fullerene can be a cationic, such as a quaternary ammonium, fullerene derivative and the poiythiophene can bear an anionic linker precursor group, such as a carboxylate. In various embodiments, at one of the poiythiophene and the fullerene derivative can be water-soluble. This component can dissolved in water, then contacted with the other component, optionally also in solution in water or in a water-soluble organic solvent. For instance, a water-soluble poiythiophene such as poly [3- (potassium-5-pentanoate)thiophene-2,5-diyl], highly regioregular,

is commercially available from Rieke Metals, Inc., of Lincoln, NE, can be used. A sulfonate-containing form can be prepared by conversion of this carboxylic acid to a taurine (β-aminoethanesulfonic acid) amide, accordingly providing a method of ionic conjugate formation wherein the polythiophene comprises a linker precursor group comprising a carboxylate or sulfonate group.

The cationic fullerene derivative can be a compound of formula formula

wherein m and m' are each independently 0 to about 12, i.e., an ester or ether of PCBA and choline or a homolog thererof. Or, the cationic fullerene can be a compound of formula

formula

wherein each R is independently selected from the set consisting of hydrogen, alkyl, and aryl, or two R^l groups together with the nitrogen atom to which they are bonded form a 3-8 membered heterocyclyl, optionally substituted, and optionally further comprising 1-3 addition heteroatoms selected from O, NR¹, and S(0)_q wherein q is 0, 1, or 2. See, for example, R. Bullard-Dillard, et al., "Tissue Sites of Uptake of ^I4C-iabeled C60" (1996), Bioorg. Chem., 24, 376.

As described above, the inventive methods can comprise at least 1%, or at least 5%, or at least 10%, of the thienyl repeating units of the polythiophene reacting with the fullerene to yield a covalently coupled fuller ene-thienyl repeating unit. In various embodiments, fuller ene-bearing polythiophenes of the invention can be prepared through polymerization of a fullerene-substituted dihalothiophene, such as a fullerene-substituted 2,5-dihalothiophene and, optionally, copolymerizing a dihalothiophene, such as a 2,5-dihalothiophene, that does not bear a fullerene group, in the presence of a metal catalyst. In various embodiments, methods of polymerization of 2,5-dihalothiophenes whether or not each monomer unit bears a fullerene group, can be carried out as described in published PCT patent application WO 2009/056497, and references cited therein, which are incorporated by reference herein. For example, the dihalothiophene can be a dichlorothiophene or a dibromothiophene.

The methods of preparing regioregular conducting polythiophene polymers bearing fullerene groups as disclosed herein can utilize activated metals, which insert metal atoms directly into halo-aromatic or halo- heteroaromatic carbon bonds. Preferably, the activated metal is Rieke zinc (Zn*). Regioregular conducting polymers are provided if, for example, a nickel (II) catalyst or a platinum catalyst is used to accomplish the polymerization. The fullerene-substituted polythiophene conducting polymers can be poly(3- substituted-thiophene) homopolymers, or poly(3,4-disubstituted-thiophene) homopolymers, wherein some or all of the 3- or the 4-substituents comprise fullerene groups. Preferably, the regioregular conducting polymers bearing fullerene groups are ITT poly(3-substituted-thiophenes) or HT poly(3,4- disubstituted-thiophenes).

The present invention provides a method of preparing regioregular conducting polymer including adding a nickel (II) catalyst to a solution of a monomer-metal complex to provide the regioregular conducting polymer, wherein at least some of the monomer units bear a fullerene group bonded thereto, typically via a linker. This method used can involve "reverse-addition of "normal-addition" methodologies with respect to the order in which a solution of a monomer-metal complex and a solution of a nickel (II) catalyst are combined. In various embodiments, a manganese (II) catalyst can also be employed. In various embodiments, the "reverse-addition" method can afford regioregular conducting polymers with higher regioregularity than those obtained by the "normal-addition" method. This increase in regioregularity is very advantageous because it is very difficult to raise the ratio of the regioregular to regiorandom polymer. Further, higher regioregularity results in higher conductivity of the regioregular conducting polymers. This can be particularly advantageous with the fullerene-bearing regioregu lar polythiophenes of the present invention that are adapted for use in photovoltaic devices such as solar cells.

The thienyl monomer-metal complex may be prepared by a method including contacting a 2,5-dibalo-substituted monomer, which can bear a fullerene substituent on the 3- position or on both the 3- and 4-positions with an activated metal, a Grignard reagent, or an organozinc reagent such as RZnX wherein R is an alkyl group, a dialkyl zinc reagent (R₂Zn), or a trialkylzineate reagent (R₃ZnM wherein M is a metal ion); for example, wherein R is a (C₂- C₁₂)alkyl group, M is magnesium, manganese, lithium, sodium, or potassium, and X is F, C1, Br, or 1. Preferably the dihalo-substituted monomer is a 2,5- dichloro- or 2,5-dibromo-thiophene and the activated metal is an activated aluminum, manganese, copper, zinc, magnesium, calcium, titanium, iron, cobalt, nickel, indium, or a combination thereof. More preferably, the activated metal is Rieke zinc (Zn*).

In various embodiments, a thienyl monomer bearing a fullerene group can be of formula

wherein Z is independently selected halo, such as chloro or bromo or iodo, although typically the two Z groups are the same halogen; R¹ is hydrogen, alkyl, or the like; and FLR is a fullerene group, coupled via linker X' to the 3-position of the thienyl monomer of formula (II). Or, a thienyl monomer unit can be a 3,4- disubstituted thienyl of formula (III)

wherein the groups are as defined for formula (II), provided that the two fullerene groups FLR and the two linkers X' can but need not be identical. In various embodiments, X' is an alkylene chain, optionally containing therewithin a double bond, a triple bond, or an aryl group, or a heteroatom selected from the set consisting of O, NR.¹, S, S(O), and S(0)2, wherein R¹ is H or alkyl, wherein the alkylene chain is optionally substituted with a hydroxyl group or a carbonyl group.

A fuller ene-bearing polythiophene of the invention can be prepared by polymerization, such as is described in WO2007/146074 and WO 2009/056497 by the inventor herein, using metal catalysts, such as nickel or palladium and the like to bring about coupling of the thienyl units. Dihalo thiophenes can be converted to organometallic derivatives such as organo-magnesium, zinc, or manganese derivatives, which then couple in the presence of the catalyst. For example, nickel can be used as a catalyst to produce regioregular

polythiophenes, and palladium can be used to produce regiorandom

polythiophenes. Polymer products resulting from the homo-polymerization of a thienyl monomer of formula (II) will provide a polythiophene bearing a fullerene group on substantially every thienyl repeating unit; homo-polymerization of a thienyl monomer of formula (III) will provide a polythiophene bearing two fullerene groups on substantially every thienyl repeating unit.

In various other embodiments, monomelic thienyl reagents of formula (II), or formula (III), or a mixture thereof, can be copolymer ized with analogous thienyl monomers lacking fullerene substituents. In this way, the average degree of substitution (DS) of the polythiophene polymer with fullerene units can be predicted based on the relative proportions of monomer reagents used with and without fullerene groups bonded thereto. For example, as the fuller ene- thiophene bond of a monomeric thienyl unit can be stable to the conditions of polymerization, the average degree of substitution can be directly calculated from the ratio of reagents.

Similarly to the fullerene-polymer conjugate prepared by coupling a fullerene to a linker precursor group in an intact (e.g., preformed) polythiophene polymer, a fullerene-polythiophene conjugate formed by polymerization or copolymerization of fullerene-substituted thienyl monomeric reagents, optionally with other thienyl monomeric reagents, can provide a product wherein the fullerene groups are bonded to the polythiophene backbone via a linker of various lengths and rigidities. For example, if the linker is an alkyl chain, the length can be varied from a single carbon up to about 24 carbon atoms total, bearing in mind that the alkyl chain can also contain optional heteroatoms inserted therein, e.g., oxygen, sulfur (thioether, sulfoxide, sulfone), or nitrogen. A more rigid linker can be obtained by the presence of groups such as olefmic double bonds, acetylenic triple bonds, aryls, fused bicyclic aryls, and the like, in the linker. Unsubstituted alkyl chains are comparatively flexible, and can fold, whereas groups like acetylenic triple bonds are rigid linear groups that cannot fold, forcing at least four carbon atoms per triple bond into a linear

configuration. Similarly, a phenyl group can add rigidity and can serve to fix a minimum distance between the fullerene group and the polythiophene backbone, as the degrees of freedom are limited. Since it is believed that the spacing between the fullerene group and the polythiophene backbone can influence the efficiency of photo-induced electron transfer therebetween, the inventors herein believe that optimum linkers can be developed without undue experimentation.

The present invention is also directed to a regioregular conducting polymer composed of an improved regioregular conducting polymer having superior electroconducting properties. The improved regioregular conducting polymer is characterized by its monomelic composition, its degree of regioregularity, and its physical properties such as its molecular weight and number average molecular weight, its polydispersity, its conductivity, its purity obtained directly from its preparatory features, as well as other properties. The improved regioregular conducting polymer is characterized as well by the process for its preparation.

The degree of substitution of the polythiophene polymer by the fullerene can vary. Not every thienyl unit of the polythiophene is substituted with a fullerene, as the steric requirements of the C60-fullerene or the even larger C70- fullerene are believed to preclude this high degree of substitution, although it is theoretically possible. In various embodiments, there is on average more than one fullerene per polythiophene molecule, i.e., per polymer chain. Polymers of higher molecular weight, i.e., of a greater number of thienyl repeating units, can bear more fullerene conjugate groups than can shorter-chain forms of the polythiophene. In various embodiments, about 1% to about 10% of the thienyl repeating units of the polythiophene bears a fullerene. Or, about 1% to about 5% of the thienyl repeating units of the polythiophene bears a fullerene. In other embodiments, the fullerene content can be high, such as 50%, or up to 100% in some embodiments. The average content of fullerenes in a sample of a polythiophene-fuilerene conjugate of the invention can be determined through the use of standard analytical techniques including elemental analysis, gel permeation chromatography, mass spectrometry, ¹³C NMR in solution or in the solid state, and the like.

In various embodiments, a polythiophene-fuilerene of the invention, or prepared by a method of the invention, suitable for use in a photovoltaic device, can have a purity of at least about 85%, or at least about 90%, or at least about 95%, or at least about 99%. Polythiophene-fullerenes prepared by a method of the invention can be purified following the polymerization step described above, such as by solvent extraction, e.g., with hexane then chloroform or methylene chloride, optionally two or more times in a Sohxlet extractor or similar device.

Compositions of the invention can be formed as films or layers, suitable for use in photovoltaic generation of electrici ty, where the surface area of a light receptor device determines how much light, e.g., sunlight, can be intercepted and consequently sets a limit on the amount of electricity that can be generated by the device, adjusted for the photoefficiency of the photovoltaic device.

In various embodiments, the invention provides a film comprising a composition of the invention. The film can also include other materials, such as binders to increase physical film strength, and such as adjuvant materials for absorbing light and relaying energy from a molecularly excited state to the polythiophene-fuilerene conjugate. Film geometry can be adjusted to provide for maximal electrical generation per mass of the inventive composition, which is an economically significant factor in determining the cost of solar electricity. Excessively thick layers of the primary photovoltaic material are economically ineffecient.

A film of the invention can be prepared by distributing a composition of the invention, optionally combined with binders, adjuvants, and the like, on a supporting surface. The supporting surface can include electrically conductive elements to allow collection of the electrical current generated by light exposure. A film of the invention can be disposed in a photovoltaic device having a supporting conductor as well as a conductive cover glass, such as ITO (indium titanium oxide) glass, allowing for a device that can generate a voltage potential and support significant flow of electrical current therefrom.

In various embodiment, the invention provides a photovoltaic device incorporating a polythiophene-fullerene conjugate of the invention or prepared by a method of the invention. Such photovoltaic devices can exhibit a high photoefficiency relative to other polythiophene-containing organic photovoltaic devices, or relative to other photovoltaic devices in general.

Figure 1 shows a block diagram example of a photovoltaic device 100 according to an embodiment of the invention. The photovoltaic device 100 includes a first electrode 1 10 and a second electrode 1 12 separated by a polymer 120. The polymer 120 includes a donor portion 124 and an acceptor portion 122. In the example of Figure 1, the donor portion 124 and the acceptor portion 122 are mixed to form bulk heterojunctions that provide short diffusion distances between donor portions 124 and acceptor portions 122. In one example the mixing of th e d onor portion 124 an d the acceptor portion 122 i s random. In one example a level of microstructural order is present in the mixing of the donor portion 124 and the acceptor portion 122.

An electronic device 130 is also illustrated, coupled to the photovoltaic device 100 via circuitry 132. In an example operation, photons incident upon the photovoltaic device 100 create exitons in the polymer 120. The exitons are separated into electrons and holes at interfaces between the donor portions 124 and acceptor portions 122. Electrons then flow through the circuitry 132 to provide current to operate the electronic device 130. Examples of acceptor portions 122 include fullerene structures as described herein. Examples of donor portions include polythiophene polymers as described herein.

Figure 2 shows another block diagram example of a photovoltaic device 200 according to an embodiment of the invention. The photovoltaic device 200 includes a first electrode 210 and a second electrode 212. An acceptor layer 222 is shown, forming an interface with the first electrode 210, A donor layer 224 is shown forming an interface with the second electrode 220 and the acceptor layer 222. Similar to Figure I, an electronic device 230 is illustrated in Figure 2, coupled to the photovoltaic device 200 via circuitry 232. In an example operation, photons incident upon the photovoltaic device 200 create exitons in the donor layer 224. The exitons are separated into electrons and holes at the interface between the donor layer 224 and the acceptor layer 222. Electrons then flow through the circuitry 232 to provide current to operate the electronic device 230. An example material for the acceptor layer 222 includes fullerene structures as described herein. An example material for the donor layer 224 includes polythiophene polymers as described herein.

A composition of the invention, or a composition prepared by a method of the invention, can be a component of a photovoltaic device, such as a solar panel. It is contemplated by the inventor herein that an inventive composition can be used in an art solar panel, such as that described in R. Radbeh, et al, "Nanoscale control of the network morphology of high efficiency polymer fullerene solar cells by the use of high material concentration in the liquid phase", Nanotechnology (2010), 21, 1-8, and references cited therein. The inventor herein believes that the highly intimate, controllable degree of contact between the photo-excited electron-generating polythiophene, and the electron- accepting fullerene, can provide an enhanced photoefficiency in a device such as described in the above document. The surface area of contact between electron donor and electron acceptor, being at the molecular level with the conjugates of the invention is necessarily greater than can be achieved using nanoscale control, as nanostructures involve pluralities of individual molecules.

The inventor herein also contemplates that the inventive compositions can be optimized for photoefficiency by variation of the spacing between polythiophene and fullerene, and by the nature of the linker group.

Preparation of alcohol

Method 1

Procedure:

Put 0.5g of polymer [4033] in a 50 mL round bottom flask (rbf). Attach an oil bubbler and purge with Ar for 5 minutes. Add 10 mL of chloroform and cool to 0° C. 2.5 mL of borane tetrahydrofuran complex. Stir for 3 hours. Add 10 mL water. Separate phases and back extract 3 times with 20 mL chloroform Strip off solvent and dry under high vacuum for 1 hour.

Coupling [4033] alcohol with PCBM

Method 1

Procedure:

Put 0.5g of polymer alcohol in a 500 mL round bottom flask (rbf) under Ar. Purge with Ar for 5 minutes. Add 100 mL of chloroform and 0 35mL pyridine Added 0020g of (6,6>Phenyl-C61 butyric acid (PCBM). Reflux for 3 hours. Strip off solvent on rotovap. Dry under high vacuum for 1 hour. Coupling [4033] alcohol with PCBM

Method 2

Procedure:

Put 0.5g of polymer alcohol in a 500 mL round bottom flask (rbf) under Ar. Purge with Ar for 5 minutes. Add 100 mL of THF and 4 mL n-Butyllithium (1.6M in hexanes) and stirred 30 minutes. Added 0.020g of (<5.6)-Phenyl-C61 butyric acid (PCBM). Reflux for 3 hours. Strip off solvent on rotovap. Dry under high vacuum for 1 hour.

Preparation of acid chloride

Method 1

Procedure:

Put 0.5g of polymer [4033] in a 50 mL round bottom flask (rbf). Attach a condenser, oil bubbler, and KOH trap. Purge with Ar for 5 minutes. Add 10 mL of chloroform and 0.1 mL DMF. Add thionyl chloride and heat gently until bubbling stops. Remove solvent by simple distillation. Pull high vacuum for 1 hour using a dry ice trap and a KOH trap to protect the vacuum pump. Preparation of acid chloride

Method 2

Procedure:

Put 0.5g of polymer [4033] in a 50 mL round bottom flask (rbf) Attach a short path distillation apparatus connected to an oil bubbler, and KOH trap. Purge with Ar for 5 minutes. Add 10 mL of thionyl chloride and heat gentry until bubbling stops. Remove excess thionyl chloride by simple distillation under atmospheric pressure. Pull high vacuum for 1 hour to remove any trace thionyl chloride, using a dry ice trap and a KOH trap to protect the vacuum pump.

Coupling [4033] with PCBA

Method 1

Procedure:

Put 0.5g of polymer acid chloride in a 50 mL round bottom flask (rbf). Attach a condenser and purge with Ar for 5 minutes. Add 10 mL of chloroform and 0.18 mL pyridine. Added 0.020g of (6,6)-Phenyl-C61 butyric acid (PCBA) . Reflux gently for 3 hours. Strip off solvent on rotovap. Add 20 mL toluene and strip off using the rotovap to help remove any residual pyridine. Dry under high vacuum for 1 hour. Coupling [4033] with PCBA

Method 2

Procedure:

Put 0.5g of polymer [4033] in a 500 mL round bottom flask (rbf) under Ar. Purge with Ar for 5 minutes. Add 100 mL of chloroform and O.lg DMAP. Added 0.020g of (6,6)- Phenyi-C61 butyric acid (PCBA) . Add 2.2 mL of DCC solution. Stir for 12 hours. Strip off solvent on rotovap Dry under nigh vacuum for 1 hour.

Notes:

DMAP is 4-(Dimethylaniino)pyridine

DCC is dicyclohexylcarbodiimide. The solution used was 1M in CH₂Cl₂. but is also sold in xylenes and l-Methyl-2-pyrroHdone (NMP)

Ketene Coupling with Fullerene-C₆₀

Method 1

Procedure:

Put 0.5g of polymer acid chloride in a 50 mL round bottom flask (rbf). Add 10 mL of THF and 0.35 mL Triemylamine. Stirred for 1 hour. Added 0.016g of Fulerene-C60. Stirred for 3 hours. Strip off solvent on rotovap. Dry under high vacuum for 1 hour.

Note: Can also be done with fullerene-C₇₀

All patents and publications referred to herein are incorporated by

reference herein to the same extent as if each indi vidual publication was

specifically and individually indicated to be incorporated by reference in its

entirety.

The terms and expressions which have been employed are used as terms

of description and not of limi tation, and there is no intention that in the use of

such terms and expressions of excluding any equivalents of the features shown

and described or portions thereof, but it is recognized that various modifications

are possible within th e scope of th e invention claimed. Thus, i t should be

understood that although the present invention has been specifically disclosed by

preferred embodiments and optional features, modification and variation of the

concepts herein disclosed may be resorted to by those skilled in the art, and that

such modifications and variations are considered to be within the scope of this

invention as defined by the appended claims.

Claims

CLAIMS What is claimed is:

1. A composition for photovoltaic electrical generation, comprising a polythiophene polymer having thienyl repeating units, wherein at least some of the thienyl repeating units not disposed at a polymer chain terminus are co valently or ionically bonded via respective linkers to respective fullerene groups.

2. The composition of claim 1 wherein the polythiophene polymer is a regioregular polymer.

3. The composition of claim 1 wherein the polythiophene polymer has a molecular weight of about 1,000 to about 200,000 daltons.

4. The composition of claim 1 wherein the polythiophene polymer is a 2,5- polythiophene.

5. The composition of claim 1 wherein the polythiophene polymer comprises monosubstituted thienyl repeating units.

6. The composition of claim 1 comprising a regioregular HT-2,5- polythiophene, comprising monosubstituted thienyl repeating units, wherein the composition is of formula (I)

wherein each independently selected X comprises a linker precursor group comprising a reactive group; X' is a linker bonded covalently to at least one of the monosubstituted thienyl repeating units wherein X' can comprise covalent bonds, ionic bonds, or both;

n and n' are each independently about 3 to about 10,000; and each star * indicates a continuing chain with a terminal atom, each chain optionally bearing additional Mlerenes linked to the regioregular polythiophene by linker X'.

7. The composition of claim 6 wherein X' is an alkylene chain, optionally containing therewithin a double bond, a triple bond, or an aryl group, or a heteroatom selected from the set consisting of O, NR.¹, S, S(Q), and S(O)₂ wherein R¹ is H or alkyl, wherein the alkylene chain is optionally substituted with a hydroxyl group or a carbonyl group.

8. The composition of claim 1 comprising a polythiophene- fullerene conjugate of formula

X' is a linker resulting from covalent or ionic bond formation between the linker precursor group of X and a suitable fullerene reactant.

9. The composition of claim 8 comprising a polythiophene-fullerene conjugate of formula

or of formula

or of formula

or of formula

and

m is 0 to about 12:

n and n' are each independently about 3 to about 10,000; and X is a linker precursor group;

Y is (CH₂)_r, (CII₂)_rCHOH(CH₂)_r, (CH₂)_rNR¹ (CH₂)_r, (CH₂)_r 0(CH₂)_r, (CH₂), S(O)_q(CH₂)_r, or (CH,)_r S(O)₀NR¹ (CH₂)_r, wherein each independently selected r is 0 to about 24, q is 0, 1, or 2, and R¹ is H or alkyl.

10. The composition of any one of claims 7-9 wherein X comprises a optionally substituted (C1-C12) alkylene chain optionally further comprising unsaturation, cyclic groups, and heteroatoms selected from O, NR, and S, wherein R is H or alkyl, the alkylene bearing a reactive group or derivative thereof.

11. The composition of claim 10 wherein the reactive group is an acid, an ester, a hydroxyl, an amino, or a carbonyl group.

12. The composition of claim 10 wherein X comprises a (C1 -C 12) alkylene chain, terminally substituted with C0₂R¹ or COR¹, OH, halo, or NHR¹ wherein R¹ is H or alkyl.

13. The composition of claim 8 wherein X' comprises an ester, an amide, an anhydride, an alkylation product, or an olefination product.

14. The composition of claim 13 wherein X' comprises an alkylene chain in which is optionally disposed an ester, an amide, an anhydride, a double bond, or a carbinol group..

15. The composition of claim 9 of formula

wherein m - 2 and Y is NR(CH₂)_r, 0(CH₂)_r, OC(=O)(CH₂)_r, or (CH₂)_r,

16. The composition of claim 9 of formula

wherein m = 2 and Y is (CH₂)_r, or CH₂C(=O)(CH₂)_r.

17. The composition of claim 9 of formula

or of formula

wherein R² is alkyl.

18. The composition of claim 7 wherein X' comprises at least one ionic bond.

19. The composition of claim 18 wherein X' comprises a bond between a cationic quaternary ammonium ion and an anionic carboxylate or sulfonate ion.

20. The composition of claim 19 wherein the cationic ion is comprised by a cationic fullerene derivative.

21 , The composition of claim 20 wherein the cationic fullerene derivative is a compound of formula

wherein m and m' are each independently 0 to about 12.

22. The composition of claim 20 wherein the canonic Mlerene derivative is a compound of formula

wherein each R¹ is independently selected from the set consisting of hydrogen, alkyl, and aryl, or two R¹ groups together with the nitrogen atom to which they are bonded form a 3-8 membered heterocyclyl, optionally substituted, and optionally further comprising 1-3 addition heteroatoms selected from O, NR¹, and S(O)_q wherein q is 0, 1, or 2.

23. The composition of claim 1 wherein there is on average more than one fulierene per polythiophene molecule.

24. The composition of claim 1 wherein about 0.1 % to at least about 50 % of the thienyl repeating units of the polythiophene bears a fulierene.

25. The composition of claim 24 wherein about 1% to about 5% of the thienyl repeating units of the polythiophene bears a fulierene.

26. A film comprising a composition of claim 1.

27. The film of claim 26 further comprising additional light-gathering substances.

28. A method of preparing a composition of claim 1, comprising contacting a polythiophene polymer bearing a linker precursor group and a fulierene suitable to react with the linker precursor group to form a polythiophene-linker-fullerene material.

29. The method of claim 28 wherein the linker precursor group comprises a carbene-generating moiety and the fullerene is an underivatized fullerene.

30. The method of claim 28 wherein the linker precursor group comprises a nucleophilic group, and the fullerene is a derivatized fullerene comprising an electrophilic group.

31. The method of claim 28 wherein the linker precursor group comprises a electrophilic group, and the fullerene is a derivatized fullerene comprising an nucleophilic group.

32. The method of claim 30 wherein the derivatized fullerene is a fullerene carboxylic acid, carboxylic ester, or carboxaldehyde.

33. The method of claim 30 wherein the derivatized fullerene is a fullerene alkyl halide or alkyl sulfonate ester.

34. The method of claim 32 or 33 wherein the nucleophilic group is a hydroxyl, amino, thiol, carboxylic acid group, organolithium group, Grignard reagent, or Reformatsky reagent.

35. The method of claim 31 wherein the linker precursor group comprises a carboxylic acid, carboxylic ester, or carboxaldehyde.

36. The method of claim 31 wherein the linker precursor group comprises an alkyl halide or alkyl sulfonate ester.

37. The method of claim 35 or 36 wherein the nucleophilic group is a hydroxyl, amino, thiol, carboxylic acid group, organolithium group, Grignard reagent, or Reformatsky reagent.

38. The method of claim 28 wherein one of the linker precursor group and the derivatized fullerene comprises a carboxaldehyde or ketone group, and the other comprises a phosphonium ylide, a a-phosphonyl carbanion, an

organolithium reagent, a Grignard reagent, or a Reformasky reagent.

39. The method of claim 28 wherein the derivatized fullerene is PCBA or PCBM, and the linker precursor group of the polythiophene comprises a carbinol group, an amino group, or a carboxylic acid group.

40. The method of claim 39 wherein the polythiophene is a 2,5-HT- regioregular polythiophene 3 -substituted with a hydroxyalkyl, aminoalkyl, or alkylcarboxylate group.

41. The method of claim 28 wherein one of the polythiophene linker precursor group and the fullerene comprises a cationic group, and the other comprises an anionic group.

42. The method of claim 41 wherein at least one of the polythiophene and the fullerene is water-soluble, and the water-soluble polythiophene or fullerene is dissolved in water, then is contacted with the other of the polythiophene or fullerene, optionally also in solution in water or in a water-soluble organic solvent.

43. The method of claim 41 wherein the polythiophene comprises a linker precursor group comprising a carboxylate or sulfonate group.

The method of claim 41 wherein the fullerene is a compound of formula

wherein m and m' are each independently 0 to about 12.

The method of claim 41 wherein the fullerene is a compound of formula

wherein each R is independently selected from the set consisting of hydrogen, alkyl, and aryl, or two R^l groups together with the nitrogen atom to which they are bonded form a 3-8 membered heterocyclyl, optionally substituted, and optionally further comprising 1-3 addition heteroatoms selected from O, NR¹, and S(O)_q wherein q is 0, 1, or 2.

46. A method of preparing the composition of claim 1 , comprising polymerizing, in the presence of a metallic catalyst, a halothiophene

organometallic reagent, the reagent being prepared by contacting a

dihalothiophene bearing a fullerene group and metal or metal derivative.

47. The method of claim 46 wherein the metallic catalyst comprises nickel or palladium.

48. The method of claim 46 wherein the halothiophene organometallic reagent is a zinc, magnesium, or manganese organometallic reagent.

49. The method of claim 46, further comprising copolymerizing with the dihalothiophene bearing a fullerene group a second dihalothiophene not bearing a fullerene group.

50 The method of any one of claims 46-49 wherein the dihalothiophene bearing a fullerene group is of formula (II) or of formula (III)

wherein each Z is independently selected halo; R¹ is hydrogen, or is unsubstituted or substituted alkyl or is unsubstituted or substituted aryl; each FLR is an independently selected fuller ene, and each X' is an independently selected linker.

51. The method of claim 46 wherein the dihalothiophene is a 2,5- dichlorothiophene or a 2,5-dibromothiophene, bearing a fullerene.

52. The method of claim 50 wherein the dihalothiophene bearing a fullerene group is of formula (II), and X' is an alkylene chain, optionally containing therewithin a double bond, a triple bond, or an aryl group, or a heteroatom selected from the set consisting of O, NR1, S, S(O), and S(O)2, wherein R¹ is II or alkyl, wherein the alkylene chain is optionally substituted with a hydroxyl group or a carbonyl group.

53. A method of preparing a film comprising applying a composition made by a method of claim 26 to a surface.

54. The method of claim 53 wherein the composition is first dissolved in a solvent, then applied to a surface, then the solvent removed.

55. A photovoltaic device comprising the composition of claim 1.

56. The photovoltaic device of claim 55 wherein a plurality of cells of the composition or film, respectively connected to conductors, is adapted to produce a voltage between conductors when the cells are under solar illumination.

57. A photovoltaic device comprising:

a first electrode and a second electrode separated by a polymer, wherein the polymer includes:

a polythiophene polymer having thienyl repeating unite; and a number of fullerene groups in contact with the polythiophene polymer; wherein at least some of the thienyl repeating units not disposed at a polymer chain terrain as are covalently or ionically bonded via respective linkers to respective fullerene groups.

58. The photovoltaic device of claim 57, wherein the polythiophene polymer and fullerene groups are mixed to form a composite material.

59. The photovoltaic device of claim 57, wherein the polythiophene polymer and fullerene groups are formed in alternating layers.