ORGANIC SEMICONDUCTORS

Abstract

The invention relates to novel organic semiconducting compounds containing a polycyclic unit, to methods for their preparation and educts or intermediates used therein, to compositions and formulations containing them, to the use of the compounds and compositions as organic semiconductors in, or for the preparation of, organic electronic (OE) devices, especially organic photovoltaic (OPV) devices, organic photodetectors (OPD), organic field effect transistors (OFET) and organic light emitting diodes (OLED), and to OE devices comprising these compounds or compositions.

Claims

1. A compound comprising one or more divalent heteroarylene units of formula I ##STR00106## wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings Ar.sup.1,2 arylene or heteroarylene that has from 5 to 20 ring atoms, is mono- or polycyclic, optionally contains fused rings, and is unsubstituted or substituted by one or more identical or different groups L, X.sup.1, X.sup.2, X.sup.3 O, S or Se, U.sup.1 CR.sup.1R.sup.2, SiR.sup.1R.sup.2, GeR.sup.1R.sup.2, NR or CO, U.sup.2 CR.sup.3R.sup.4, SiR.sup.3R.sup.4, GeR.sup.3R.sup.4, NR.sup.3 or CO, R.sup.1-4 H, F, Cl or straight-chain, branched or cyclic alkyl with 1 to 30 C atoms, in which one or more CH.sub.2 groups are optionally replaced by O, S, C(O), C(S), C(O)O, OC(O), NR.sup.0, SiR.sup.0R.sup.00, CF.sub.2, CR.sup.0CR.sup.00, CY.sup.1CY.sup.2 or CC in such a manner that 0 and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN, and in which one or more CH.sub.2 or CH.sub.3 groups are optionally replaced by a cationic or anionic group, or aryl, heteroaryl, arylalkyl, heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of the aforementioned cyclic groups has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L, and the pair of R.sup.1 and R.sup.2 and/or the pair of R.sup.3 and R.sup.4 together with the C, Si or Ge atom to which they are attached, may also form a spiro group with 5 to 20 ring atoms which is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L, L F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen.

2. The compound of claim 1, wherein Ar.sup.1 and Ar.sup.2 are selected from the following formulae ##STR00107## ##STR00108## wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings W S, O or Se, V CR.sup.1 or N, R.sup.5-11 H, F, Cl or straight-chain, branched or cyclic alkyl with 1 to 30 C atoms, in which one or more CH.sub.2 groups are optionally replaced by O, S, C(O), C(S), C(O)O, OC(O), NR.sup.0, SiR.sup.0R.sup.00, CF.sub.2, CR.sup.0CR.sup.00, CY.sup.1CY.sup.2 or CC in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN, and in which one or more CH.sub.2 or CH.sub.3 groups are optionally replaced by a cationic or anionic group, or aryl, heteroaryl, arylalkyl, heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of the aforementioned cyclic groups has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L as defined in claim 1.

3. The compound of claim 2, wherein Ar.sup.1 and Ar.sup.2 are selected from the following formulae ##STR00109## wherein W, V and R.sup.5-9 have the meanings given in claim 2.

4. The compound according to claim 1, wherein the units of formula I are selected from the following subformulae ##STR00110## wherein U.sup.1,2 are as defined in claim 1.

5. The compound according to claim 2, wherein R.sup.1-11 are selected from the following groups the group consisting of R, OR and SR wherein R is straight-chain or branched alkyl with 1 to 20 C atoms which is unsubstituted or substituted by one or more F atoms, the group consisting of C(O)R, C(O)OR, OC(O)R, C(O)NHR and C(O)NRR.sup.n, wherein R and R.sup.n are independently of each other straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, and the group consisting of aryl, aryloxy, heteroaryl and heteroaryloxy, each of which has 4 to 20 ring atoms and optionally contains fused rings and is unsubstituted or substituted by one or more groups L.

6. The compound according to claim 1, which is a conjugated polymer comprising one or more units of formula I, and further comprising one or more arylene or heteroarylene units that have from 5 to 20 ring atoms, are mono- or polycyclic, do optionally contain fused rings, are unsubstituted or substituted by one or more identical or different groups L, and are either selected of formula I or are structurally different from formula I, and wherein all the aforementioned units are directly connected to each other.

7. The compound of claim 6, which comprises one or more repeating units of formula II1 or II2, and optionally one or more repeating units of formula II3:
(Ar.sup.1).sub.aU(Ar.sup.2).sub.b(Ar.sup.3).sub.c(Ar.sup.4).sub.dII1
(Ar.sup.1).sub.a(Ar.sup.2).sub.bU(Ar.sup.3).sub.c(Ar.sup.4).sub.dII2
(Ar.sup.1).sub.a(Ar.sup.2).sub.b(Ar.sup.3).sub.c(Ar.sup.4).sub.dII3 wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings U a unit of formula I, Ar.sup.1-4 arylene or heteroarylene that has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, is unsubstituted or substituted by one or more identical or different groups L, and is different from U, and a, b, c, d 0 or 1, wherein in formula II3 a+b+c+d1.

8. The compound according to claim 7, which is selected of formula III: ##STR00111## wherein A is a unit of formula I, II1 or II2, B is a unit of formula I, II1, II2 or II3, x is >0 and 1, y is 0 and <1, x+y is 1, and n is an integer 5.

9. The compound according to claim 8, which is selected from the following formulae ##STR00112## ##STR00113## wherein U.sup.1 is CR.sup.1R.sup.2, SiR.sup.1R.sup.2, GeR.sup.1R.sup.2, NR.sup.1 or CO, U.sup.2 is CR.sup.3R.sup.4, SiR.sup.3R.sup.4, GeR.sup.3R.sup.4, NR.sup.3 or CO, Ar.sup.1-4 is arylene or heteroarylene that has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, is unsubstituted or substituted by one or more identical or different groups L, a-d are each 0 or 1, x is >0 and 1, y is 0 and <1, x+y is 1, and n is an integer 5.

10. The compound according to claim 8, which is selected of formula IV
R.sup.21-chain-R.sup.23IV wherein chain denotes a polymer chain selected from formulae III, R.sup.21 and R.sup.23 denote, independently of each other, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, or denote, independently of each other, H, F, Br, Cl, I, CH.sub.2Cl, CHO, CRCR.sub.2, SiRRR, SiRXX, SiRRX, SnRRR, BRR, B(OR)(OR), B(OH).sub.2, OSO.sub.2R, CCH, CCSiR.sub.3, ZnX or an endcap group, X and X denote halogen, and R, R and R denote, independently of each other, H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, and two of R, R and R may also form a cyclosilyl, cyclostannyl, cycloborane or cycloboronate group with 2 to 20 C atoms together with the respective hetero atom to which they are attached.

11. The compound according to claim 7, wherein one or more of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 denote arylene or heteroarylene of the following formulae ##STR00114## ##STR00115## ##STR00116## ##STR00117## wherein R.sup.11, R.sup.12, R.sup.13, and R.sup.14, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen.

12. The compound according to claim 7, wherein one or more of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 denote arylene or heteroarylene of the following formulae ##STR00118## ##STR00119## wherein R.sup.11, R.sup.12, R.sup.13, and R.sup.14, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SON, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen.

13. The compound according to claim 7, wherein one or more of Ar.sup.1, Ar.sup.2, Ar.sup.2 and Ar.sup.4 denote arylene or heteroarylene of the following formulae ##STR00120## ##STR00121## wherein R.sup.11 and R.sup.12, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen.

14. (canceled)

15. A compound of formula V1 or V2
R.sup.23(Ar.sup.1).sub.aU(Ar.sup.2).sub.b(Ar.sup.3).sub.c(Ar.sup.4).sub.dR.sup.24V1
R.sup.23(Ar.sup.1).sub.a(Ar.sup.2).sub.bU(Ar.sup.3).sub.c(Ar.sup.4).sub.dR.sup.24V2 wherein U, Ar.sup.1-4, a, b, c and d have the meanings given in claim 7, R.sup.23 and R.sup.24 are independently of each other H, Cl, Br, I, O-tosylate, O-triflate, O-mesylate, O-nonaflate, SiMe.sub.2F, SiMeF.sub.2, OSO.sub.2Z.sup.1, B(OZ.sup.2).sub.2, CZ.sup.3C(Z.sup.3).sub.2, CCH, CCSi(Z.sup.1).sub.3, ZnX.sup.0 or Sn(Z.sup.4).sub.3, X.sup.0 is halogen, and Z.sup.1-4 are each independently C.sub.1-10 alkyl or C.sub.6-12 aryl, each being optionally substituted, and two groups Z.sup.2 may also form a cycloboronate group having 2 to 20 C atoms together with the B- and O-atoms, wherein at least one of R.sup.23 and R.sup.24 is different from H.

16. A compound of formula VI
R.sup.T1(Ar.sup.1).sub.e(Ar.sup.2).sub.f[(Ar.sup.3).sub.g(Ar.sup.4).sub.hU(Ar.sup.5).sub.i(Ar.sup.6).sub.k].sub.o(Ar.sup.7).sub.l(Ar.sup.8).sub.mR.sup.T2VI wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings U a unit of formula I as defined in claim 1, Ar.sup.1-8 arylene or heteroarylene that has from 5 to 20 ring atoms, is mono- or polycyclic, optionally contains fused rings, and is unsubstituted or substituted by one or more identical or different groups L as defined in claim 1, or CY.sup.1CY.sup.2 or CC, Y.sup.1, Y.sup.2 H, F, Cl or CN, R.sup.T1, R.sup.T2 a carbyl or hydrocarbyl group with 1 to 30 C atoms that is optionally substituted by one or more groups L as defined in claim 1 and optionally comprises one or more hetero atoms, e-m 0 or 1, and o 1, 2 or 3.

17. The compound of claim 16, wherein R.sup.T1 and R.sup.T2 are selected from H, F, Cl, Br, NO.sub.2, CN, CF.sub.3, R*, CF.sub.2R*, OR*, SR*, SO.sub.2R*, SO.sub.3R*, C(O)H, C(O)R*, C(S)R*, C(O)CF.sub.2R*, C(O)OR*, C(S)OR*, OC(O)R*, OC(S)R*, C(O)SR*, SC(O)R*, C(O)NR*R**, NR*C(O)R*, NHR*, NR*R**, CR*CR*R**, CCR*, CCSiR*R**R***, SiR*R**R***, CHCH(CN), CHC(CN).sub.2, C(CN)C(CN).sub.2, CHC(CN)(R.sup.a), CHC(CN)C(O)OR*, CHC(COOR*).sub.2, CHC(CONR*R**).sub.2, and the following formulae ##STR00122## ##STR00123## ##STR00124## ##STR00125## ##STR00126## ##STR00127## ##STR00128## ##STR00129## wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings R.sup.a, R.sup.b aryl or heteroaryl, each having from 4 to 30 ring atoms, optionally containing fused rings and being unsubstituted or substituted with one or more groups L, or one of the meanings given for L, R*, R**, R*** alkyl with 1 to 20 C atoms which is straight-chain, branched or cyclic, and is unsubstituted, or substituted with one or more F or Cl atoms or CN groups, or perfluorinated, and in which one or more C atoms are optionally replaced by O, S, C(O), C(S), SiR.sup.0R.sup.00, NR.sup.0R.sup.00, CHR.sup.0CR.sup.00 or CC such that O- and/or S-atoms are not directly linked to each other, L F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, L H or one of the meanings of L, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 12 C atoms that is optionally fluorinated, Y.sup.1, Y.sup.2 H, F, Cl or CN, X.sup.0 halogen, r 0, 1, 2, 3 or 4, s 0, 1, 2, 3, 4 or 5, t 0, 1, 2 or 3, and u 0, 1 or 2.

18. The compound of claim 16, wherein one or both of R.sup.T1 and R.sup.T2 denote an electron withdrawing group.

19. The compound according to claim 17, wherein R.sup.T1 and R.sup.T2 are selected from the following formulae ##STR00130##

20. (canceled)

21. A composition comprising one or more compounds according to claim 1 and one or more additional compounds having one or more of semiconducting, charge transport, hole or electron transport, hole or electron blocking, electrically conducting, photoconducting or light emitting properties.

22. The composition of claim 21, wherein at least one of said one or more compounds is a p-type semiconductor, and said composition further comprises one or more n-type semiconductors.

23. The composition of claim 21, wherein at least one of said one or more compounds is an n-type semiconductor, and said composition further comprises one or more p-type semiconductors.

24. A bulk heterojunction (BHJ) formed from a composition according to claim 21.

25. A formulation comprising one or more compounds according to claim 1, and further comprising one or more solvents selected from organic solvents.

26. (canceled)

27. An electronic or optoelectronic device, or a component thereof, or an assembly comprising it, comprising a compound according to claim 1.

28. The electronic or optoelectronic device according to claim 27, which is selected from organic field effect transistors (OFET), organic thin film transistors (OTFT), organic light emitting diodes (OLED), organic light emitting transistors (OLET), organic photovoltaic devices (OPV), organic photodetectors (OPD), organic solar cells, dye-sensitized solar cells (DSSC), perovskite-based solar cells, laser diodes, Schottky diodes, photoconductors, photodetectors and thermoelectric devices.

29. The component according to claim 27, which is selected from charge injection layers, charge transport layers, interlayers, planarising layers, antistatic films, polymer electrolyte membranes (PEM), conducting substrates and conducting patterns.

30. The assembly according to claim 27, which is selected from integrated circuits (IC), radio frequency identification (RFID) tags, security markings, security devices, flat panel displays, backlights of flat panel displays, electrophotographic devices, electrophotographic recording devices, organic memory devices, sensor devices, biosensors and biochips.

31. A process of preparing a compound according to claim 6, said process comprising: coupling one or more compounds of formula V1 or formula V2 with each other and/or with one or more monomers of formulae MI-MIV in an aryl-aryl coupling reaction
R.sup.23(Ar.sup.1).sub.aU(Ar.sup.2).sub.b(Ar.sup.3).sub.c(Ar.sup.4).sub.dR.sup.24V1
R.sup.23(Ar.sup.1).sub.a(Ar.sup.2).sub.bU(Ar.sup.3).sub.c(Ar.sup.4).sub.dR.sup.24V2
R.sup.23Ar.sup.1R.sup.24MI
R.sup.23Ar.sup.2R.sup.24MII
R.sup.23Ar.sup.3R.sup.24MIII
R.sup.23Ar.sup.4R.sup.24MIV wherein U a unit of formula I, Ar.sup.1-4 arylene or heteroarylene that has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, is unsubstituted or substituted by one or more identical or different groups L, and is different from U, a, b, c, d 0 or 1, wherein in formula II3 a+b+c+d1, R.sup.23 and R.sup.24 are independently of each other H, Cl, Br, I, O-tosylate, O-triflate, O-mesylate, O-nonaflate, SiMe.sub.2F, SiMeF.sub.2, OSO.sub.2Z.sup.1, B(OZ.sup.2).sub.2, CZ.sup.3C(Z.sup.3).sub.2, CCH, CCSi(Z.sup.1).sub.3, ZnX.sup.0 or Sn(Z.sup.4).sub.3, X.sup.0 is halogen, and Z.sup.1-4 are each independently C.sub.1-10 alkyl or C.sub.6-12 aryl, each being optionally substituted, and two groups Z.sup.2 may also form a cycloboronate group having 2 to 20 C atoms together with the B- and O-atoms, wherein at least one of R.sup.23 and R.sup.24 is different from H.

32. The compound according to claim 7, wherein Ar.sup.1-4 are selected from: (a) formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37, D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140, D141 and D150, ##STR00131## ##STR00132## ##STR00133## ##STR00134## wherein R.sup.11, R.sup.12, R.sup.13, and R.sup.14, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen; (b) formulae A1, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92, A98 and A103, ##STR00135## ##STR00136## ##STR00137## wherein R.sup.11, R.sup.12, R.sup.13, and R.sup.14, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen; or (c) formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14, ##STR00138## ##STR00139## wherein R.sup.11 and R.sup.12, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30, preferably 1 to 20, C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen.

33. The compound according to claim 16, wherein Ar.sup.1-8 are selected from: (a) formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37, D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140, D141 and D150, ##STR00140## ##STR00141## ##STR00142## ##STR00143## wherein R.sup.11, R.sup.12, R.sup.13, and R.sup.14, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen; (b) formulae A1, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92, A98 and A103, ##STR00144## wherein R.sup.11, R.sup.12, R.sup.13, and R.sup.14, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30, C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1to 20 C atoms that is optionally fluorinated, X.sup.0 halogen; or (c) formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14, ##STR00145## ##STR00146## ##STR00147## ##STR00148## wherein R.sup.11 and R.sup.12, independently of each other, denote H, F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, R.sup.0, R.sup.00 H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, X.sup.0 halogen.

Description

DETAILED DESCRIPTION

[0100] The compounds of the present invention are easy to synthesize and exhibit advantageous properties. They show good processability for the device manufacture process, high solubility in organic solvents, and are especially suitable for large scale production using solution processing methods.

[0101] Co-polymers derived from monomers of the present invention and electron acceptor monomers show low bandgaps, high charge carrier mobilities, high external quantum efficiencies in BHJ solar cells, good morphology when used in p/n-type blends e.g. with fullerenes, high oxidative stability, a long lifetime in electronic devices, and are promising materials for organic electronic OE devices, especially for OPV devices with high power conversion efficiency.

[0102] The compounds of the present invention are especially suitable as p-type semiconductors for the preparation of blends of p-type and n-type semiconductors which are suitable for use in BHJ photovoltaic devices.

[0103] Besides, the compounds of the present invention show the following advantageous properties: [0104] i) Additional solubility can be introduced into the compound by inclusion of various solubilizing groups in R.sup.1-11 positions. [0105] ii) Additional fine-tuning of the electronic energies (HOMO/LUMO levels) by co-polymerisation with appropriate co-monomer(s) can afford attractive candidate materials for OPV and/or OPD applications. [0106] iii) The polycyclic units of formula I have planar structures that enable strong pi-pi stacking in the solid state leading to improved charge transport properties in the form of higher charge carrier mobility. [0107] iv) An incorporation of various substituents into the poylcyclic core results in monomers with either electron donating property, like for example dialkyl-substituted core, or electron accepting property, like for example dialkyl ester-substituted core. [0108] v) The unit of formula I can thus be altered from a donor unit to an acceptor unit by switching the nature of the solubilising groups, for example from electron donating groups like alkyl or alkoxy to electron withdrawing groups like ketone or ester, thus allowing a much broader applicability of the core for use in OPV or OPD polymers [0109] vi) Using both units of formula I substituted by electron donating groups like alkyl or alkoxy and units of formula I substituted by electron withdrawing groups like ketone or ester, it is possible to create a donor-acceptor polymer from units of formula I, optionally with spacer units like thiophene, dithiophene or thienothiophene to keep the backbone flat, but without further donor or acceptor units. Such polymers are expected to have a high Voc.

[0110] In the units of formula I and its subformulae Ar.sup.1 and Ar.sup.2 are preferably selected from the following formulae:

##STR00005## ##STR00006##

wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings [0111] W S, O or Se, [0112] V Ca.sup.1 or N, [0113] R.sup.5-11 H, F, Cl or straight-chain, branched or cyclic alkyl with 1 to 30, preferably 1 to 20, C atoms, in which one or more CH.sub.2 groups are optionally replaced by O, S, C(O), C(S), C(O)O, OC(O), NR.sup.0, SiR.sup.0R.sup.00, CF.sub.2, CR.sup.0CR.sup.00, CY.sup.1CY.sup.2 or CC in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN, and in which one or more CH.sub.2 or CH.sub.3 groups are optionally replaced by a cationic or anionic group, or aryl, heteroaryl, arylalkyl, heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of the aforementioned cyclic groups has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L as defined in formula I,

[0114] Very preferably Ar.sup.1 and Ar.sup.2 are selected from the following formulae:

##STR00007##

wherein W, V and R.sup.5-9 have the meanings given above and below, and wherein W is preferably S and V is preferably CH.

[0115] Preferred units of formula I are selected from the following subformulae

##STR00008##

wherein U.sup.1,2 are as defined in formula I, and preferably U.sup.1 and U.sup.2 denote CR.sup.1R.sup.2 and CR.sup.3R.sup.4 respectively.

[0116] In the units of formula I and its subformulae preferably R.sup.1-4 are different from H.

[0117] Preferably R.sup.1-4 are selected from the following groups or any combination thereof: [0118] the group consisting of R, OR and SR wherein R is straight-chain or branched alkyl with 1 to 20 C atoms which is unsubstituted or substituted by one or more F atoms, [0119] the group consisting of C(O)R, C(O)OR, OC(O)R, C(O)NHR and C(O)NRR.sup.n, wherein R and R.sup.n are independently of each other straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, [0120] the group consisting of aryl, aryloxy, heteroaryl and heteroaryloxy, each of which has 4 to 20 ring atoms and optionally contains fused rings and is unsubstituted or substituted by one or more groups L as defined in formula I.

[0121] If R.sup.1-4 denote an aryl(oxy) or heteroaryl(oxy) group, it is preferably selected from phenyl, naphthyl, phenanthryl, anthracenyl, indenyl, pyrrole, furan, pyridine, thiazole, thiophene, thieno[3,2-b]thiophene or thieno[2,3-b]thiophene, each of which is unsubstituted or substituted with one or more groups L, preferably with one or more groups selected from F and alkyl, alkoxy or thioalkyl each having from 1 to 20 C atoms and being optionally fluorinated.

[0122] Very preferred groups R.sup.1-4 are selected from the group consisting of phenyl, 4-biphenyl, 2-indenyl, 1- or 2-naphthyl, 1-, 2- or 3-phenanthrenyl and 1-, 2- or 9-anthracenyl, all of which are optionally substituted by one or more groups R.sup.5 which are preferably selected from straight-chain or branched alkyl or alkoxy with 1 to 20 C atoms that is optionally fluorinated.

[0123] Most preferred groups R.sup.1-4 in the units of formula I and its subformulae denote phenyl that is substituted in 4-position by a group R.sup.5 as defined above.

[0124] Preferably R.sup.5-11, if being different from H, are selected from the following groups or any combination thereof: [0125] the group consisting of R, OR and SR wherein R is straight-chain or branched alkyl with 1 to 20 C atoms which is unsubstituted or substituted by one or more F atoms, [0126] the group consisting of C(O)R, C(O)OR, OC(O)R, C(O)NHR and C(O)NRR.sup.n, wherein R and R.sup.n are independently of each other straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated, [0127] the group consisting of aryl, aryloxy, heteroaryl and heteroaryloxy, each of which has 4 to 20 ring atoms and optionally contains fused rings and is unsubstituted or substituted by one or more groups L as defined in formula I, preferably.

[0128] If R.sup.5-11 denote an aryl(oxy) or heteroaryl(oxy) group, it is preferably selected from phenyl, naphthyl, phenanthryl, anthracenyl, indenyl, pyrrole, furan, pyridine, thiazole, thiophene, thieno[3,2-b]thiophene or thieno[2,3-b]thiophene, each of which is unsubstituted or substituted with one or more groups L, preferably with one or more groups selected from F and alkyl, alkoxy or thioalkyl each having from 1 to 20 C atoms and being optionally fluorinated.

[0129] In another preferred embodiment of the present invention one or more of R.sup.1-11 denote straight-chain, branched or cyclic alkyl with 1 to 20 C-atoms wherein one or more CH.sub.2 or CH.sub.3 groups are substituted by a cationic or anionic group.

[0130] The cationic group is preferably selected from the group consisting of phosphonium, sulfonium, ammonium, uronium, thiouronium, guanidinium or heterocyclic cations such as imidazolium, pyridinium, pyrrolidinium, triazolium, morpholinium or piperidinium cation.

[0131] Preferred cationic groups are selected from the group consisting of tetraalkylammonium, tetraalkylphosphonium, N-alkylpyridinium, N,N-dialkylpyrrolidinium, 1,3-dialkylimidazolium, wherein alkyl preferably denotes a straight-chain or branched alkyl group with 1 to 12 C atoms.

[0132] Further preferred cationic groups are selected from the group consisting of the following formulae

##STR00009## ##STR00010##

wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 denote, independently of each other, H, a straight-chain or branched alkyl group with 1 to 12 C atoms or non-aromatic carbo- or heterocyclic group or an aryl or heteroaryl group, each of the aforementioned groups having 3 to 20, preferably 5 to 15, ring atoms, being mono- or polycyclic, and optionally being substituted by one or more identical or different substituents L as defined below, or denote a link to the respective group R.sup.1-4.

[0133] In the above cationic groups of the above-mentioned formulae any one of the groups R.sup.1, R.sup.2, R.sup.3 and R.sup.4 (if they replace a CH.sub.3 group) can denote a link to the group R.sup.1, or two neighbored groups R.sup.1, R.sup.2, R.sup.3 or R.sup.4 (if they replace a CH.sub.2 group) can denote a link to the respective group R.sup.1-4.

[0134] The anionic group is preferably selected from the group consisting of borate, imide, phosphate, sulfonate, sulfate, succinate, naphthenate or carboxylate, very preferably from phosphate, sulfonate or carboxylate.

[0135] The compounds according to the present invention include small molecules, monomers, oligomers and polymers.

[0136] A preferred embodiment of the present invention relates to a conjugated polymer comprising, preferably consisting of, one or more repeating units of formula II1 and/or II2, and optionally one or more repeating units of formula II3:

(Ar.sup.1).sub.aU(Ar.sup.2).sub.b(Ar.sup.3).sub.c(Ar.sup.4).sub.dII1

(Ar.sup.1).sub.a(Ar.sup.2).sub.bU(Ar.sup.3).sub.c(Ar.sup.4).sub.dII2

(Ar.sup.1).sub.a(Ar.sup.2).sub.b(Ar.sup.3).sub.c(Ar.sup.4).sub.dII3

wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings [0137] U a unit of formula I or its subformulae as defined above and below, [0138] Ar.sup.1-4 arylene or heteroarylene that has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, is unsubstituted or substituted by one or more identical or different groups L, and is different from U, [0139] a, b, c, d 0 or 1, wherein in formula II3 a+b+c+d1.

[0140] Preferably the conjugated polymer comprises one or more repeating units of formula II1 or II2 wherein a+b+c+c1.

[0141] Further preferably the conjugated polymer comprises one or more repeating units of formula II1 wherein b=1 and a=c=d=0 and one or more repeating units of formula II3 wherein a=b=1 and c=d=0.

[0142] Further preferably the conjugated polymer comprises two or more distinct repeating units of formula UU1 wherein b=1 and a=c=d=0.

[0143] Further preferably at least one of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 is an arylene or heteroarylene group as being defined in formula II1 and having electron acceptor property.

[0144] Preferably L denotes F or is selected from the following groups [0145] the group consisting of R, OR and SR wherein R is straight-chain or branched alkyl with 1 to 20 C atoms which is unsubstituted or substituted by one or more F atoms, [0146] the group consisting of C(O)R, C(O)OR, OC(O)R, C(O)NHR and C(O)NRR.sup.n, wherein R and R.sup.n are independently of each other straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated,

[0147] Further preferably the conjugated polymer according to the present invention is selected of formula III:

##STR00011##

wherein [0148] A is a unit of formula I, II1 or II2 as defined above and below, [0149] B is a unit of formula I, II1, II2 or II3 as defined above and below, [0150] x is >0 and 1, [0151] y is 0 and <1, [0152] x+y is 1, and [0153] n is an integer 5.

[0154] Preferred polymers of formula III are selected from the following subformulae

##STR00012## ##STR00013## ##STR00014##

wherein U.sup.1-2 have the meanings of formula I or one of the preferred meanings given above and below, Ar.sup.1-4 and a-d have the meanings of formula Ill or one of the preferred meanings given above and below, and x, y and n have the meanings of formula III or one of the preferred meanings given above and below.

[0155] In the polymers of formula III and its subformulae, x and y denote the mole fraction of repeating units A and B, respectively, and n denotes the degree of polymerisation or total number of repeating units A and B. These formulae include block copolymers, random or statistical copolymers and alternating copolymers of A and B, as well as homopolymers of A for the case when x>0 and y=0.

[0156] In the polymers of formula III and its subformulae, x is preferably from 0.1 to 0.9, very preferably from 0.3 to 0.7.

[0157] In the polymers of formula III and its subformulae, y is preferably from 0.1 to 0.9, very preferably from 0.3 to 0.7.

[0158] In the polymers according to the present invention, the total number of repeating units n is preferably from 2 to 10,000. The total number of repeating units n is preferably 5, very preferably 10, most preferably 50, and preferably 500, very preferably 1,000, most preferably 2,000, including any combination of the aforementioned lower and upper limits of n.

[0159] The polymers of the present invention include homopolymers and copolymers, like statistical or random copolymers, alternating copolymers and block copolymers, as well as combinations thereof.

[0160] Further preferably the conjugated polymer is selected of formula IV

R.sup.21-chain-R.sup.22IV

wherein chain denotes a polymer chain selected of formulae III and III1a-III3e, and R.sup.21 and R.sup.22 have independently of each other one of the meanings of L as defined above, or denote, independently of each other, H, F, Br, Cl, I, CH.sub.2Cl, CHO, CRCR.sub.2, SiRRR, SiRXX, SiRRX, SnRRR, BRR, B(OR)(OR), B(OH).sub.2, OSO.sub.2R, CCH, CCSiR.sub.3, ZnX or an endcap group, X and X denote halogen, R, R and R have independently of each other one of the meanings of R.sup.0 given in formula I, and preferably denote alkyl with 1 to 12 C atoms, and two of R, R and R may also form a cyclosilyl, cyclostannyl, cycloborane or cycloboronate group with 2 to 20 C atoms together with the respective hetero atom to which they are attached.

[0161] Preferred endcap groups R.sup.21 and R.sup.22 are H, C.sub.1-20 alkyl, or optionally substituted C.sub.6-12 aryl or C.sub.2-10 heteroaryl, very preferably H or phenyl.

[0162] Especially preferred are repeating units and polymers of formulae II1, II2, III, III1a-III3e, IV and their subformulae wherein one or more of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 denote arylene or heteroarylene, preferably having electron donor properties, selected from the group consisting of the following formulae

##STR00015## ##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025## ##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035## ##STR00036## ##STR00037## ##STR00038## ##STR00039##

wherein R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.16, R.sup.17 and R.sup.18 independently of each other denote H or have one of the meanings of L as defined above and below.

[0163] Preferred donor units are selected from formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37, D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140, D141 or D150 wherein preferably at least one of R.sup.11, R.sup.12, R.sup.13 and R.sup.14 is different from H.

[0164] Further preferred are repeating units and polymers of formulae II1, II2, III, III1a-III3e, IV and their subformulae wherein one or more of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 denote arylene or heteroarylene, preferably having electron acceptor properties, selected from the group consisting of the following formulae

##STR00040## ##STR00041## ##STR00042## ##STR00043## ##STR00044## ##STR00045## ##STR00046## ##STR00047## ##STR00048## ##STR00049## ##STR00050## ##STR00051## ##STR00052## ##STR00053## ##STR00054## ##STR00055## ##STR00056##

wherein R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15 and R.sup.16 independently of each other denote H or have one of the meanings of L as defined above and below.

[0165] Preferred acceptor units are selected from formulae A1, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92, A98 or A103 wherein preferably at least one of R.sup.11, R.sup.12, R.sup.13 and R.sup.14 is different from H.

[0166] Further preferred are repeating units and polymers of formulae II1, II2, III, III1a-III3e, IV and their subformulae wherein one or more of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 denote arylene or heteroarylene selected from the group consisting of the following formulae

##STR00057## ##STR00058##

wherein R.sup.11 and R.sup.12 independently of each other denote H or have one of the meanings of L as defined above and below.

[0167] Very preferred are units selected from formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14, wherein preferably one of R.sup.11 and R.sup.12 is H or both R.sup.11 and R.sup.12 are H.

[0168] Further preferred are repeating units and polymers of formulae II1, II2, III, III1a-III3e, IV and their subformulae wherein [0169] a) one or more of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 denote arylene or heteroarylene, preferably having electron donor properties, selected from the group consisting of the formulae D1-D145, very preferably of the formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37, D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140, D141 and D150, and/or [0170] b) one or more of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 denote arylene or heteroarylene, preferably having electron accpetor properties, selected from the group consisting of the formulae A1-A98, very preferably of the formulae A1, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92, A98 and A103, and [0171] c) one or more of Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 denote arylene or heteroarylene selected from the group consisting of the formulae Sp1-Sp17, very preferably of the formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14.

[0172] Another preferred embodiment of the present invention relates to a small molecule or oligomer of formula VI

R.sup.T1(Ar.sup.1).sub.e(Ar.sup.2).sub.f[(Ar.sup.3).sub.g(Ar.sup.4).sub.hU(Ar.sup.5).sub.i(Ar.sup.6).sub.k].sub.o(Ar.sup.7).sub.l(Ar.sup.8).sub.mR.sup.T2VI

wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings [0173] U a unit of formula I or its subformulae, [0174] Ar.sup.1-8 arylene or heteroarylene that has from 5 to 20 ring atoms, is mono- or polycyclic, optionally contains fused rings, and is unsubstituted or substituted by one or more identical or different groups L as defined in formula I, or CY.sup.1CY.sup.2 or [0175] Y.sup.1, Y.sup.2 H, F, Cl or CN, [0176] R.sup.T1, R.sup.T2 a carbyl or hydrocarbyl group with 1 to 30 C atoms that is optionally substituted by one or more groups L and optionally comprises one or more hetero atoms, [0177] e-m 0 or 1, preferably with at least one of e-m being 1, [0178] o 1, 2 or 3.

[0179] Preferred groups R.sup.T1 and R.sup.T2 in formula I are selected from H, F, Cl, Br, NO.sub.2, CN, CF.sub.3, R*, CF.sub.2R*, OR*, SR*, SO.sub.2R*, SO.sub.3R*, C(O)H, C(O)R*, C(S)R*, C(O)CF.sub.2R*, C(O)OR*, C(S)OR*, OC(O)R*, OC(S)R*, C(O)SR*, SC(O)R*, C(O)NR*R**, NR*C(O)R*, NHR*, NR*R**, CR*CR*R**, CCR*, CCSiR*R**R***, SiR*R**R***, CHCH(CN), CHC(CN).sub.2, C(CN)C(CN).sub.2, CHC(CN)(R.sup.a), CHC(CN)C(O)OR*, CHC(COOR*).sub.2, CHC(CONR*R**).sub.2, and the group consisting of the following formulae

##STR00059## ##STR00060## ##STR00061## ##STR00062## ##STR00063## ##STR00064##

wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings [0180] R.sup.a, R.sup.b aryl or heteroaryl, each having from 4 to 30 ring atoms, optionally containing fused rings and being unsubstituted or substituted with one or more groups L, or one of the meanings given for L, [0181] R*, R**, R*** alkyl with 1 to 20 C atoms which is straight-chain, branched or cyclic, and is unsubstituted, or substituted with one or more F or Cl atoms or CN groups, or perfluorinated, and in which one or more C atoms are optionally replaced by O, S, C(O), C(S), SiR.sup.0R.sup.00, NR.sup.0R.sup.00, CHR.sup.0CR.sup.00 or CC such that O- and/or S-atoms are not directly linked to each other,

[0182] L F, Cl, NO.sub.2, CN, NC, NCO, NCS, OCN, SCN, R.sup.0, OR.sup.0, SR.sup.0, C(O)X.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, NH.sub.2, NHR.sup.0, NR.sup.0R.sup.00, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, SO.sub.3R.sup.0, SO.sub.2R.sup.0, OH, NO.sub.2, CF.sub.3, SF.sub.5, or optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30, preferably 1 to 20, C atoms that is optionally substituted and optionally comprises one or more hetero atoms, preferably F, CN, R.sup.0, OR.sup.0, SR.sup.0, C(O)R.sup.0, C(O)OR.sup.0, OC(O)R.sup.0, OC(O)OR.sup.0, C(O)NHR.sup.0, C(O)NR.sup.0R.sup.00, [0183] L H or one of the meanings of L, [0184] R.sup.0, R.sup.00H or straight-chain or branched alkyl with 1 to 20, preferably 1 to 12 C atoms that is optionally fluorinated, [0185] Y.sup.1, Y.sup.2 H, F, Cl or CN, [0186] X.sup.0 halogen, preferably F or Cl, [0187] r 0, 1, 2, 3 or 4, [0188] s 0, 1, 2, 3, 4 or 5, [0189] t 0, 1, 2 or 3, [0190] u 0, 1 or 2.

[0191] Preferred compounds of formula VI are those wherein one or both, preferably both, of R.sup.T1 and R.sup.T2 denote an electron withdrawing group.

[0192] Preferred electron withdrawing groups R.sup.T1 and R.sup.T2 are selected from CN, C(O)OR*, C(S)OR*, CHCH(CN), CHC(CN).sub.2, C(CN)C(CN).sub.2, CHC(CN)(R.sup.a), CHC(CN)C(O)OR*, CHC(COOR*).sub.2, and formulae T1-T53.

[0193] Very preferred groups R.sup.T1 and R.sup.T2 are selected from the following formulae

##STR00065##

wherein L, r and s have the meanings given above and below, and L is H or has one of the meanings given for L. Preferably in these formulae L is H. Further preferably in these formulae r is 0.

[0194] The above formulae T1-T53 are meant to also include their respective E- or Z-stereoisomer with respect to the CC bond in -position to the adjacent group Ar.sup.1.8, thus for example the group

##STR00066##

may also denote

##STR00067##

[0195] Preferred compounds of formula VI are selected from the following subformulae

##STR00068##

wherein R.sup.1-4, R.sup.T1, R.sup.T2, Ar.sup.1, Ar.sup.8, e and m have the meanings given above.

[0196] Further preferred are compounds of formula VI wherein Ar.sup.1-8 are selected from the following groups [0197] a) the group consisting of the formulae D1-D145, very preferably of the formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37, D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140, D141 and D150, [0198] b) the group consisting of the formulae A1-A98, very preferably of the formulae A1, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92, A98 and A103, [0199] c) the group consisting of the formulae Sp1-Sp17, very preferably of the formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14.

[0200] Further preferred compounds of formula VI are selected from the following preferred embodiments, including any combination thereof: [0201] m is 1, [0202] a and h are 0, 1 or 2, and c-f are 0, [0203] Ar.sup.1-8 are selected from formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14, [0204] R.sup.T1 and R.sup.T2 are selected from formulae T10, T36, T37, T38, T39 and T47, [0205] R.sup.T1 and R.sup.T2 are selected from formula T47.

[0206] Further preferred compounds of formula VI are those wherein m is 1, a and h are 0 or 1, c-f are 0, Ar.sup.1-8 are selected from formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14, and R.sup.T1 and R.sup.T2 are selected from formulae R1-R5, very preferably from formula R5.

[0207] Further preferred compounds of formula VI are selected from the following subformulae

##STR00069## ##STR00070## ##STR00071## ##STR00072## ##STR00073##

[0208] The above formulae VI1a-VI3h do also include their E- or Z-stereoisomers with respect to the CC double bond of the terminal group in a-position to the adjacent group Ar.sup.1 or Ar.sup.8, for example the group

##STR00074##

on each occurrence identically or differently may also denote

##STR00075##

[0209] Another preferred embodiment of the present invention relates to a monomer of formula V1 or V2

R.sup.23(Ar.sup.1).sub.aU(Ar.sup.2).sub.b(Ar.sup.3).sub.c(Ar.sup.4).sub.dR.sup.24V1

R.sup.23(Ar.sup.1).sub.a(Ar.sup.2).sub.bU(Ar.sup.3).sub.c(Ar.sup.4).sub.dR.sup.24V2

wherein U, Ar.sup.1-4, a, b, c and d have the meanings of formula II1, or one of the preferred meanings as described above and below, and R.sup.23 and R.sup.24 are independently of each other selected from the group consisting of H, which is preferably an activated CH bond, Cl, Br, I, O-tosylate, O-triflate, O-mesylate, O-nonaflate, SiMe.sub.2F, SiMeF.sub.2, OSO.sub.2Z.sup.1, B(OZ.sup.2).sub.2, CZ.sup.3C(Z.sup.3).sub.2, CCH, CCSi(Z.sup.1).sub.3, ZnX.sup.0 and Sn(Z.sup.4).sub.3, wherein X.sup.0 is halogen, Z.sup.1-4 are selected from the group consisting of alkyl and aryl, preferably C.sub.1-10 alkyl and C.sub.6-12 aryl, each being optionally substituted, and two groups Z.sup.2 may also form a cycloboronate group having 2 to 20 C atoms together with the B- and O-atoms, and wherein at least one of R.sup.23 and R.sup.24 is different from H, and preferably both of R.sup.23 and R.sup.24 are different from H.

[0210] Very preferred are monomers of formula V1 and V2 and their subformulae wherein a+b+c+d1.

[0211] Further preferred are monomers of formula V1 and its subformulae wherein a+b+c+d=0.

[0212] Further preferred are monomers of formula V1 and V2 and their subformulae wherein R.sup.23 and R.sup.24 are selected from Br, B(OZ.sup.2).sub.2 and Sn(Z.sup.4).sub.3.

[0213] Further preferred are monomers selected from the following subformulae

R.sup.23Ar.sup.1UAr.sup.2R.sup.24V1a

R.sup.23UR.sup.24V1b

R.sup.23Ar.sup.1UR.sup.24V1c

R.sup.23UAr.sup.2R.sup.24V1d

wherein U, Ar.sup.1, Ar.sup.2, R.sup.23 and R.sup.24 are as defined in formula V1.

[0214] Very preferred are monomers of formula V1 and V2 and their subformulae wherein R.sup.23 and R.sup.24 are selected from Br, B(OZ.sup.2).sub.2 and Sn(Z.sup.4).sub.3.

[0215] Further preferred are monomers of formulae V1, V2, V1a-V1d and their subformulae wherein Ar.sup.1 and/or Ar.sup.2 are selected from the following groups [0216] a) the group consisting of the formulae D1-D145, very preferably of the formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37, D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140, D141 and D150, [0217] b) the group consisting of the formulae A1-A98, very preferably of the formulae A1, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92, A98 and A103, [0218] c) the group consisting of the formulae Sp1-Sp17, very preferably of the formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14.

[0219] The polymers according to the present invention can be prepared for example by copolymerising one or more monomers of formula V1, V2 or V1a-V1d with each other or with one or monomers of the following formulae in an aryl-aryl coupling reaction

R23-Ar.sup.1R.sup.24MI

R.sup.23Ar.sup.2R.sup.24MII

R.sup.23Ar.sup.3R.sup.24MIII

R.sup.23Ar.sup.4R.sup.24MIV

wherein Ar.sup.1-4, R.sup.23 and R.sup.24 have the meanings given in formula II2 and V1 or one of the preferred meanings given above and below.

[0220] The polymer according to the present invention can be synthesized according to or in analogy to methods that are known to the skilled person and are described in the literature. Other methods of preparation can be taken from the examples.

[0221] For example, the polymer can be suitably prepared by aryl-aryl coupling reactions, such as Yamamoto coupling, CH activation coupling, Suzuki coupling, Stille coupling, Sonogashira coupling, Heck coupling or Buchwald coupling. Suzuki coupling, Stille coupling and Yamamoto coupling are especially preferred. The monomers which are polymerised to form the repeat units of the polymers can be prepared according to methods which are known to the person skilled in the art.

[0222] Preferably the polymer is prepared from monomers selected from formulae V1, V2, V1a-d and MI-MIV as described above.

[0223] Another aspect of the invention is a process for preparing a polymer by coupling one or more identical or different monomers selected from formulae V1, V2, V1a-d with each other and/or with one or more co-monomers, preferably selected from formulae MI-MIV, in a polymerisation reaction, preferably in an aryl-aryl coupling reaction.

[0224] Preferred aryl-aryl coupling and polymerisation methods used in the processes described above and below are Yamamoto coupling, Kumada coupling, Negishi coupling, Suzuki coupling, Stille coupling, Sonogashira coupling, Heck coupling, CH activation coupling, Ullmann coupling or Buchwald coupling. Especially preferred are Suzuki coupling, Negishi coupling, Stille coupling and Yamamoto coupling. Suzuki coupling is described for example in WO 00/53656 A1. Negishi coupling is described for example in J. Chem. Soc., Chem. Commun., 1977, 683-684. Yamamoto coupling is described in for example in T. Yamamoto et al., Prog. Polym. Sci., 1993, 17, 1153-1205, or WO 2004/022626 A1.Stille coupling is described for example in Z. Bao et al., J. Am. Chem. Soc., 1995, 117, 12426-12435. CH activation is described for example for example in M. Leclerc et al, Angew. Chem. Int. Ed. 2012, 51, 2068-2071. For example, when using Yamamoto coupling, monomers having two reactive halide groups are preferably used. When using Suzuki coupling, monomers having two reactive boronic acid or boronic acid ester groups or two reactive halide groups are preferably used. When using Stille coupling, monomers having two reactive stannane groups or two reactive halide groups are preferably used. When using Negishi coupling, monomers having two reactive organozinc groups or two reactive halide groups are preferably used. When synthesizing a linear polymer by CH activation polymerisation, preferably a monomer as described above is used wherein at least one reactive group is an activated hydrogen bond.

[0225] Preferred catalysts, especially for Suzuki, Negishi or Stille coupling, are selected from Pd(0) complexes or Pd(II) salts. Preferred Pd(0) complexes are those bearing at least one phosphine ligand such as Pd(Ph.sub.3P).sub.4. Another preferred phosphine ligand is tris(ortho-tolyl)phosphine, i.e. Pd(o-Tol.sub.3P).sub.4. Preferred Pd(II) salts include palladium acetate, i.e. Pd(Oac).sub.2 or trans-di(p-acetato)-bis[o-(di-o-tolylphosphino)benzyl]dipalladium(II). Alternatively the Pd(0) complex can be prepared by mixing a Pd(0) dibenzylideneacetone complex, for example tris(dibenzyl-ideneacetone)dipalladium(0), bis(dibenzylideneacetone)palladium(0), or Pd(II) salts e.g. palladium acetate, with a phosphine ligand, for example triphenylphosphine, tris(ortho-tolyl)phosphine, tris(o-methoxyphenyl)phosphine or tri(tert-butyl)phosphine. Suzuki polymerisation is performed in the presence of a base, for example sodium carbonate, potassium carbonate, cesium carbonated, lithium hydroxide, potassium phosphate or an organic base such as tetraethylammonium carbonate or tetraethylammonium hydroxide. Yamamoto polymerisation employs a Ni(0) complex, for example bis(1,5-cyclooctadienyl) nickel(0).

[0226] Suzuki, Stille or CH activation coupling polymerisation may be used to prepare homopolymers as well as statistical, alternating and block random copolymers. Statistical, random block copolymers or block copolymers can be prepared for example from the above monomers, wherein one of the reactive groups is halogen and the other reactive group is a CH activated bond, boronic acid, boronic acid derivative group or and alkylstannane. The synthesis of statistical, alternating and block copolymers is described in detail for example in WO 03/048225 A2 or WO 2005/014688 A2.

[0227] As alternatives to halogen as described above, leaving groups of formula OSO.sub.2Z.sup.1 can be used wherein Z.sup.1 is as defined above. Particular examples of such leaving groups are tosylate, mesylate and triflate.

[0228] Preferred polymerisation conditions lead to alternating polymers which are particularly preferred for OTFT application, whereas statistical block co-polymers are prepared preferably for OPV and OPD application. Preferred polycondensation are Suzuki coupling, Stille coupling, Sonogashira coupling, Heck coupling or Buchwald coupling, Negishi coupling or CH activation coupling where the first set of reactive groups is composed of Cl, Br, I, O-tosylate, OP-triflate, O-mesylate and O-nonaflate and the second set of reactive groups is composed of H, SiR.sub.2F, SiRF.sub.2, B(OR).sub.2, CRCHR, CCH, ZnX, MgX and Sn(R.sub.3). If a Yamamoto coupling reaction is used to prepare the polymer, the reactive monomer ends are both composed independently of Cl, Br, I, O-tosylate, O-triflate, O-mesylate and O-nonaflate.

[0229] Suitable and preferred methods for preparing compounds according to the present invention are illustrated in the reaction schemes below.

[0230] Schemes 1-4 show the synthesis of the units of formula I. Therein R and R have one of the meanings of R.sup.1 given in formula I, for example alkyl, and Ar is arylene or heteroarylene as defined in formula I.

[0231] Scheme 1 exemplarily and schematically illustrates the synthesis of unfunctionalised monomers (Y=Si or Ge, X.sup.1-3=S, O or Se).

##STR00076##

[0232] Scheme 2 exemplarily and schematically illustrates the synthesis of functionalised monomers (Y.sup.1,2=C, Si or Ge, X.sup.1-3=S, O or Se).

##STR00077##

[0233] Scheme 3 exemplarily and schematically illustrates the synthesis of a homopolymer.

TABLE-US-00001 Scheme 3 [00078] [00079] Z Z Main Reagent H H FeCl.sub.3 Br or I Br or I Ni(0) SnR.sub.3 Br or I Pd/L B(OR).sub.2 Br or I Pd/L, base

[0234] Scheme 4 exemplarily and schematically illustrates the synthesis of copolymers.

TABLE-US-00002 Scheme 4 [00080] [00081] [00082] [00083] Z Z Br or I SnR.sub.3 Br or I B(OR).sub.2 SnR.sub.3 Br or I B(OR).sub.2 Br or I

[0235] The novel methods of preparing a compound, monomer or polymer as described above and below, and the novel monomers and intermediates used therein, are further aspects of the invention.

[0236] The compounds according to the present invention can also be used in compositions or polymer blends, for example together with small molecules or other polymers having charge-transport, semiconducting, electrically conducting, photoconducting and/or light-emitting semiconducting properties, or for example with polymers having hole blocking, electron blocking properties for use as interlayers, charge blocking layers, charge transporting layer in OLED devices, OPV devices or perovskite based solar cells.

[0237] Small molecules according to the present invention which contain one or more electron withdrawing groups can also be used as n-type semiconductors. For example they can be used as replacement of, or in addition to, fullerenes, especially in mixtures or blends of p-type and n-type semiconductors for use in OPV or OPD devices. Preferred compounds for use as n-type semiconductors are those of formula VI or their subformulae, wherein R.sup.T1 and/or R.sup.T2 denote or contain an electron withdrawing group.

[0238] Another aspect of the invention relates to a composition, which may also be a polymer blend, comprising one or more compounds according to the present invention and one or more small molecule compounds and/or polymers having one or more of a charge-transport, semiconducting, electrically conducting, photoconducting, hole blocking and electron blocking property.

[0239] These compositions can be prepared by conventional methods that are described in prior art and known to the skilled person. Typically the compounds are mixed with each other or dissolved in suitable solvents and the solutions combined.

[0240] Another aspect of the invention relates to a formulation comprising one or more polymers, polymer blends or compositions as described above and below and one or more organic solvents.

[0241] Preferred solvents are aliphatic hydrocarbons, chlorinated hydrocarbons, aromatic hydrocarbons, ketones, ethers and mixtures thereof. Additional solvents which can be used include 1,2,4-trimethylbenzene, 1,2,3,4-tetra-methyl benzene, pentylbenzene, mesitylene, cumene, cymene, cyclohexylbenzene, diethylbenzene, tetralin, decalin, 2,6-lutidine, 2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzotrifluoride, N,N-dimethylformamide, 2-chloro-6-fluorotoluene, 2-fluoroanisole, anisole, 2,3-dimethylpyrazine, 4-fluoroanisole, 3-fluoroanisole, 3-trifluoro-methylanisole, 2-methylanisole, phenetol, 4-methylanisole, 3-methylanisole, 4-fluoro-3-methylanisole, 2-fluorobenzonitrile, 4-fluoroveratrol, 2,6-dimethylanisole, 3-fluorobenzo-nitrile, 2,5-dimethylanisole, 2,4-dimethylanisole, benzonitrile, 3,5-dimethyl-anisole, N,N-dimethylaniline, ethyl benzoate, 1-fluoro-3,5-dimethoxy-benzene, 1-methylnaphthalene, N-methylpyrrolidinone, 3-fluorobenzo-trifluoride, benzotrifluoride, dioxane, trifluoromethoxy-benzene, 4-fluorobenzotrifluoride, 3-fluoropyridine, toluene, 2-fluoro-toluene, 2-fluorobenzotrifluoride, 3-fluorotoluene, 4-isopropylbiphenyl, phenyl ether, pyridine, 4-fluorotoluene, 2,5-difluorotoluene, 1-chloro-2,4-difluorobenzene, 2-fluoropyridine, 3-chlorofluoro-benzene, 1-chloro-2,5-difluorobenzene, 4-chlorofluorobenzene, chloro-benzene, o-dichlorobenzene, 2-chlorofluorobenzene, p-xylene, m-xylene, o-xylene or mixture of o-, m-, and p-isomers. Solvents with relatively low polarity are generally preferred. For inkjet printing solvents and solvent mixtures with high boiling temperatures are preferred. For spin coating alkylated benzenes like xylene and toluene are preferred.

[0242] Examples of especially preferred solvents include, without limitation, dichloromethane, trichloromethane, chlorobenzene, o-dichlorobenzene, tetrahydrofuran, anisole, 2,4-dimethylanisole, 1-methylnaphthalene, morpholine, toluene, o-xylene, m-xylene, p-xylene, 1,4-dioxane, acetone, methylethylketone, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, ethyl acetate, n-butyl acetate, N,N-dimethylformamide, dimethylacetamide, dimethylsulfoxide, 1,5-dimethyltetraline, propiophenone, acetophenone, tetraline, 2-methylthiophene, 3-methylthiophene, decaline, indane, methyl benzoate, ethyl benzoate, mesitylene and/or mixtures thereof.

[0243] The concentration of the polymers in the solution is preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight. Optionally, the solution also comprises one or more binders to adjust the rheological properties, as described for example in WO 2005/055248 A1.

[0244] After the appropriate mixing and ageing, solutions are evaluated as one of the following categories: complete solution, borderline solution or insoluble. The contour line is drawn to outline the solubility parameter-hydrogen bonding limits dividing solubility and insolubility. Complete solvents falling within the solubility area can be chosen from literature values such as published in Crowley, J. D., Teague, G. S. Jr and Lowe, J. W. Jr., Journal of Paint Technology, 1966, 38 (496), 296. Solvent blends may also be used and can be identified as described in Solvents, W. H. Ellis, Federation of Societies for Coatings Technology, p 9-10, 1986. Such a procedure may lead to a blend of non solvents that will dissolve both the polymers of the present invention, although it is desirable to have at least one true solvent in a blend.

[0245] The compounds according to the present invention can also be used in patterned OSC layers in the devices as described above and below. For applications in modern microelectronics it is generally desirable to generate small structures or patterns to reduce cost (more devices/unit area), and power consumption. Patterning of thin layers comprising a polymer according to the present invention can be carried out for example by photolithography, electron beam lithography or laser patterning.

[0246] For use as thin layers in electronic or electrooptical devices the compounds, compositions or formulations according to the present invention may be deposited by any suitable method. Liquid coating of devices is more desirable than vacuum deposition techniques. Solution deposition methods are especially preferred. The formulations of the present invention enable the use of a number of liquid coating techniques. Preferred deposition techniques include, without limitation, dip coating, spin coating, ink jet printing, nozzle printing, letter-press printing, screen printing, gravure printing, doctor blade coating, roller printing, reverse-roller printing, offset lithography printing, dry offset lithography printing, flexographic printing, web printing, spray coating, curtain coating, brush coating, slot dye coating or pad printing.

[0247] Ink jet printing is particularly preferred when high resolution layers and devices needs to be prepared. Selected formulations of the present invention may be applied to prefabricated device substrates by ink jet printing or microdispensing. Preferably industrial piezoelectric print heads such as but not limited to those supplied by Aprion, Hitachi-Koki, InkJet Technology, On Target Technology, Picojet, Spectra, Trident, Xaar may be used to apply the organic semiconductor layer to a substrate. Additionally semi-industrial heads such as those manufactured by Brother, Epson, Konica, Seiko Instruments Toshiba TEC or single nozzle microdispensers such as those produced by Microdrop and Microfab may be used.

[0248] In order to be applied by ink jet printing or microdispensing, the polymers should be first dissolved in a suitable solvent. Solvents must fulfil the requirements stated above and must not have any detrimental effect on the chosen print head. Additionally, solvents should have boiling points >100 C., preferably >140 C. and more preferably >150 C. in order to prevent operability problems caused by the solution drying out inside the print head. Apart from the solvents mentioned above, suitable solvents include substituted and non-substituted xylene derivatives, di-C.sub.1-2-alkyl formamide, substituted and non-substituted anisoles and other phenol-ether derivatives, substituted heterocycles such as substituted pyridines, pyrazines, pyrimidines, pyrrolidinones, substituted and non-substituted N,N-di-C.sub.1-2-alkylanilines and other fluorinated or chlorinated aromatics.

[0249] A preferred solvent for depositing a compound according to the present invention by ink jet printing comprises a benzene derivative which has a benzene ring substituted by one or more substituents wherein the total number of carbon atoms among the one or more substituents is at least three. For example, the benzene derivative may be substituted with a propyl group or three methyl groups, in either case there being at least three carbon atoms in total. Such a solvent enables an ink jet fluid to be formed comprising the solvent with the compound or polymer, which reduces or prevents clogging of the jets and separation of the components during spraying. The solvent(s) may include those selected from the following list of examples: dodecylbenzene, 1-methyl-4-tert-butylbenzene, terpineol, limonene, isodurene, terpinolene, cymene, diethylbenzene. The solvent may be a solvent mixture, that is a combination of two or more solvents, each solvent preferably having a boiling point >100 C., more preferably >140 C. Such solvent(s) also enhance film formation in the layer deposited and reduce defects in the layer.

[0250] The ink jet fluid (that is mixture of solvent, binder and semiconducting compound) preferably has a viscosity at 20 C. of 1-100 mPa.Math.s, more preferably 1-50 mPa.Math.s and most preferably 1-30 mPa.Math.s.

[0251] The compounds, compositions and formulations according to the present invention can additionally comprise one or more further components or additives selected for example from surface-active compounds, lubricating agents, wetting agents, dispersing agents, hydrophobing agents, adhesive agents, flow improvers, defoaming agents, deaerators, diluents which may be reactive or non-reactive, auxiliaries, colourants, dyes or pigments, sensitizers, stabilizers, nanoparticles or inhibitors.

[0252] The compounds and compositions according to the present invention are useful as charge transport, semiconducting, electrically conducting, photoconducting or light emitting material in optical, electrooptical, electronic, electroluminescent or photoluminescent components or devices. In these devices, a compound or composition of the present invention is typically applied as a thin layer or film.

[0253] Thus, the present invention also provides the use of the compound, composition or layer in an electronic device. The formulation may be used as a high mobility semiconducting material in various devices and apparatus. The formulation may be used, for example, in the form of a semiconducting layer or film. Accordingly, in another aspect, the present invention provides a semiconducting layer for use in an electronic device, the layer comprising a polymer, composition or polymer blend according to the invention. The layer or film may be less than about 30 microns. For various electronic device applications, the thickness may be less than about 1 micron thick. The layer may be deposited, for example on a part of an electronic device, by any of the aforementioned solution coating or printing techniques.

[0254] The invention additionally provides an electronic device comprising a polymer, polymer blend, composition or organic semiconducting layer according to the present invention. Especially preferred devices are OFETs, TFTs, ICs, logic circuits, capacitors, RFID tags, OLEDs, OLETs, OPEDs, OPVs, OPDs, solar cells, dye-sensitized solar cells (DSSC), perovskite-based solar cells, laser diodes, photoconductors, photodetectors, electrophotographic devices, electrophotographic recording devices, organic memory devices, sensor devices, charge injection layers, Schottky diodes, planarising layers, antistatic films, conducting substrates and conducting patterns.

[0255] Especially preferred electronic device are OFETs, OLEDs, OPV and OPD devices, in particular OPD and bulk heterojunction (BHJ) OPV devices. In an OFET, for example, the active semiconductor channel between the drain and source may comprise the layer of the invention. As another example, in an OLED device, the charge (hole or electron) injection or transport layer may comprise the layer of the invention.

[0256] For use in OPV or OPD devices the polymer according to the present invention is preferably used in a composition that comprises or contains, preferably consists of, one or more p-type semiconductors and one or more n-type semiconductors.

[0257] In a preferred embodiment at least one of the p-type semiconductors in the composition is a compound according to the present invention which is preferably a conjugated polymer. In this preferred embodiment the n-type semiconductor is preferably a fullerene or substituted fullerene.

[0258] In another preferred embodiment at least one of the n-type semiconductors in the composition is a compound according to the present invention which is preferably a small molecule, very preferably a compound of formula VI. In this preferred embodiment the p-type semiconductor is preferably a conjugated polymer.

[0259] In another preferred embodiment the OPV or OPD device comprises a composition comprising a compound according to the present invention as first n-type semiconductor, and further comprising an p-type semiconductor like a conjugated polymer, and a second n-type semiconductor, which is preferably a fullerene or substituted fullerene.

[0260] The n-type semiconductor or second n-type semiconductor in the composition of the aforementioned embodiments is for example an inorganic material such as zinc oxide (ZnO.sub.x), zinc tin oxide (ZTO), titanium oxide (TiO.sub.x), molybdenum oxide (MoO.sub.x), nickel oxide (NiO.sub.x), or cadmium selenide (CdSe), or an organic material such as graphene or a fullerene, a conjugated polymer or a fullerene or substituted fullerene.

[0261] The fullerene is for example an indene-C.sub.60-fullerene bisaduct like ICBA, or a (6,6)-phenyl-butyric acid methyl ester derivatized methano C.sub.60 fullerene, also known as PCBM-C.sub.60 or C.sub.60PCBM, as disclosed for example in G. Yu, J. Gao, J. C. Hummelen, F. Wudl, A. J. Heeger, Science 1995, Vol. 270, p. 1789 ff and having the structure shown below, or structural analogous compounds with e.g. a C.sub.61 fullerene group, a C.sub.70 fullerene group, or a C.sub.71 fullerene group, or an organic polymer (see for example Coakley, K. M. and McGehee, M. D. Chem. Mater. 2004, 16, 4533).

##STR00084##

[0262] Preferably the fullerene is PCBM-C60, PCBM-C70, bis-PCBM-C60, bis-PCBM-C70, ICMA-c60 (1,4-dihydro-naphtho[2,31,2][5,6]fullerene-C60), ICBA, oQDM-C60 (1,4-dihydro-naphtho[2,3:1,9][5,6]fullerene-C60-lh), or bis-oQDM-C60.

[0263] Further preferably the n-type semiconductor or second n-type semiconductor in the composition of the aforementioned embodiments is a fullerene or substituted fullerene of formula XII,

##STR00085## [0264] C.sub.n denotes a fullerene composed of n carbon atoms, optionally with one or more atoms trapped inside, [0265] Adduct.sup.1 is a primary adduct appended to the fullerene C.sub.n with any connectivity, [0266] Adduct.sup.2 is a secondary adduct, or a combination of secondary adducts, appended to the fullerene C.sub.n with any connectivity, [0267] k is an integer 1, [0268] and [0269] l is 0, an integer 1, or a non-integer >0.

[0270] In the formula XII and its subformulae, k preferably denotes 1, 2, 3 or, 4, very preferably 1 or 2.

[0271] The fullerene C.sub.n in formula XII and its subformulae may be composed of any number n of carbon atoms Preferably, in the compounds of formula XII and its subformulae the number of carbon atoms n of which the fullerene C.sub.n is composed is 60, 70, 76, 78, 82, 84, 90, 94 or 96, very preferably 60 or 70.

[0272] The fullerene C.sub.n in formula XII and its subformulae is preferably selected from carbon based fullerenes, endohedral fullerenes, or mixtures thereof, very preferably from carbon based fullerenes.

[0273] Suitable and preferred carbon based fullerenes include, without limitation, (C.sub.60-lh)[5,6]fullerene, (C.sub.70-D5h)[5,6]fullerene, (C.sub.76-D2*)[5,6]fullerene, (C.sub.84-D2*)[5,6]fullerene, (C.sub.84-D2d)[5,6]fullerene, or a mixture of two or more of the aforementioned carbon based fullerenes.

[0274] The endohedral fullerenes are preferably metallofullerenes. Suitable and preferred metallofullerenes include, without limitation, La@C.sub.60, La@C.sub.82, Y@C.sub.82, Sc.sub.3N@C.sub.80, Y.sub.3N@C.sub.80, Sc.sub.3C.sub.2@C.sub.80 or a mixture of two or more of the aforementioned metallofullerenes.

[0275] Preferably the fullerene C.sub.n is substituted at a [6,6] and/or [5,6] bond, preferably substituted on at least one [6,6] bond.

[0276] Primary and secondary adduct, named Adduct in formula XII and its subformulae, is preferably selected from the following formulae

##STR00086## ##STR00087## ##STR00088##

wherein C.sub.n is as defined in formula XII, [0277] Ar.sup.S1, Ar.sup.S2 denote, independently of each other, an arylene or heteroarylene group with 5 to 20, preferably 5 to 15, ring atoms, which is mono- or polycyclic, and which is optionally substituted by one or more identical or different substituents having one of the meanings of L as defined above and below, and [0278] R.sup.S1, R.sup.S2, R.sup.S3, R.sup.S4, R.sup.S5 and R.sup.S6 independently of each other denote H, CN or have one of the meanings of L as defined above and below.

[0279] Preferred compounds of formula XII are selected from the following subformulae:

##STR00089## ##STR00090##

wherein C.sub.n, k and l are as defined in formula XII, and
R.sup.S1, R.sup.S2, R.sup.S3, R.sup.S4 R.sup.S5 and R.sup.S6 independently of each other denote H or have one of the meanings of L as defined above and below.

[0280] Further preferably the n-type semiconductor or second n-type semiconductor in the composition of the aforementioned embodiments is selected from graphene, metal oxides, like for example, ZnOx, TiOx, ZTO, MoOx, NiOx, quantum dots, like for example, CdSe or CdS, or conjugated polymers, like for example a polynaphthalenediimide or polyperylenediimide as described, for example, in WO2013142841 A1.

[0281] The OPV or OPD device according to the present invention preferably comprises a first transparent or semi-transparent electrode on a transparent or semi-transparent substrate on one side of the active layer, and a second metallic or semi-transparent electrode on the other side of the active layer.

[0282] Preferably, the photoactive layer in an OPV or OPD device according to the present invention is further blended with additional organic and inorganic compounds to enhance the device properties. For example, metal particles such as Au or Ag nanoparticules or Au or Ag nanoprism for enhancements in light harvesting due to near-field effects (i.e. plasmonic effect) as described, for example in Adv. Mater. 2013, 25 (17), 2385-2396 and Adv. Ener. Mater. 10.1002/aenm.201400206, a molecular dopant such as 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane for enhancement in photoconductivity as described, for example in Adv. Mater. 2013, 25(48), 7038-7044, or a stabilising agent consisting of a UV absorption agent and/or anti-radical agent and/or antioxidant agent such as 2-hydroxybenzophenone, 2-hydroxyphenylbenzotriazole, oxalic acid anilides, hydroxyphenyl triazines, merocyanines, hindered phenol, N-aryl-thiomorpholine, N-aryl-thiomorpholine-1-oxide, N-aryl-thiomorpholine-1,1-dioxide, N-aryl-thiazolidine, N-aryl-thiazolidine-1-oxide, N-aryl-thiazolidine-1,1-dioxide and 1,4-diazabicyclo[2.2.2]octane as described, for example, in WO2012095796 A1 and in WO2013021971 A1.

[0283] The device preferably may further comprise a UV to visible photo-conversion layer such as described, for example, in J. Mater. Chem. 2011, 21, 12331 or a NIR to visible or IR to NIR photo-conversion layer such as described, for example, in J. Appl. Phys. 2013, 113, 124509.

[0284] Further preferably the OPV or OPD device comprises, between the active layer and the first or second electrode, one or more additional buffer layers acting as hole transporting layer and/or electron blocking layer, which comprise a material such as metal oxides, like for example, ZTO, MoO.sub.x, NiO.sub.x, a doped conjugated polymer, like for example PEDOT:PSS and polypyrrole-polystyrene sulfonate (PPy:PSS), a conjugated polymer, like for example polytriarylamine (PTAA), an organic compound, like for example substituted triaryl amine derivatives such as N,N-diphenyl-N,N-bis(1-naphthyl)(1,1-biphenyl)-4,4diamine (NPB), N,N-diphenyl-N,N-(3-methylphenyl)-1,1-biphenyl-4,4-diamine (TPD), graphene based materials, like for example, graphene oxide and graphene quantum dots or alternatively as hole blocking layer and/or electron transporting layer, which comprise a material such as metal oxide, like for example, ZnO.sub.x, TiO.sub.x, AZO (aluminium doped zinc oxide), a salt, like for example LiF, NaF, CsF, a conjugated polymer electrolyte, like for example poly[3-(6-trimethylammoniumhexyl)thiophene], poly(9,9-bis(2-ethylhexyl)-fluorene]-b-poly[3-(6-trimethylammoniumhexyl)thiophene], or poly[(9,9-bis(3-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)], a polymer, like for example poly(ethyleneimine) or crosslinked N-containing compound derivatives or an organic compound, like for example tris(8-quinolinolato)-aluminium(III) (Alq.sub.3), phenanthroline derivative or C.sub.60 or C.sub.70 based fullerenes, like for example, as described in Adv. Energy Mater. 2012, 2, 82-86.

[0285] In a composition comprising a small molecule compound according to the present invention and further comprising a polymer, the ratio polymer:small molecule compound is preferably from 5:1 to 1:5 by weight, more preferably from 1:1 to 1:3 by weight, most preferably 1:1 to 1:2 by weight.

[0286] In a composition comprising a polymer compound according to the present invention and further comprising a fullerene or modified fullerene, the ratio polymer:fullerene is preferably from 5:1 to 1:5 by weight, more preferably from 2:1 to 1:3 by weight, most preferably 1:1 to 1:2 by weight.

[0287] The composition according to the present invention may also comprise polymeric binder, preferably from 5 to 95% by weight. Examples of binder include polystyrene (PS), polypropylene (PP), polydimethylsilane (PDMS), and polymethylmethacrylate (PMMA).

[0288] To produce thin layers in BHJ OPV devices the compounds, compositions and formulations of the present invention may be deposited by any suitable method. Liquid coating of devices is more desirable than vacuum deposition techniques. Solution deposition methods are especially preferred. The formulations of the present invention enable the use of a number of liquid coating techniques. Preferred deposition techniques include, without limitation, dip coating, spin coating, ink jet printing, nozzle printing, letter-press printing, screen printing, gravure printing, doctor blade coating, roller printing, reverse-roller printing, offset lithography printing, dry offset lithography printing, flexographic printing, web printing, spray coating, curtain coating, brush coating, slot dye coating or pad printing. For the fabrication of OPV devices and modules area printing method compatible with flexible substrates are preferred, for example slot dye coating, spray coating and the like.

[0289] In the preparation of a formulation according to the present invention, suitable solvents are preferably selected to ensure full dissolution of both the p-type and n-type component, and take into account the boundary conditions (for example rheological properties) introduced by the chosen printing method.

[0290] Organic solvent are generally used for this purpose. Typical solvents can be aromatic solvents, halogenated solvents or chlorinated solvents, including chlorinated aromatic solvents. Examples include, but are not limited to chlorobenzene, 1,2-dichlorobenzene, chloroform, 1,2-dichloroethane, dichloromethane, carbon tetrachloride, toluene, cyclohexanone, ethylacetate, tetrahydrofuran, anisole, 2,4-dimethylanisole, 1-methylnaphthalene, morpholine, toluene, o-xylene, m-xylene, p-xylene, 1,4-dioxane, acetone, methylethylketone, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, ethyl acetate, n-butyl acetate, N,N-dimethylformamide, dimethylacetamide, dimethylsulfoxide, 1,5-dimethyltetraline, propiophenone, acetophenone, tetraline, 2-methylthiophene, 3-methylthiophene, decaline, indane, methyl benzoate, ethyl benzoate, mesitylene and combinations thereof.

[0291] The OPV device can for example be of any type known from the literature (see e.g. Waldauf et al., Appl. Phys. Lett., 2006, 89, 233517).

[0292] A first preferred OPV device according to the invention comprises the following layers (in the sequence from bottom to top): [0293] optionally a substrate, [0294] a high work function electrode, preferably comprising a metal oxide, like for example ITO and FTO, serving as anode, [0295] an optional conducting polymer layer or hole transport layer, preferably comprising an organic polymer or polymer blend, for example PEDOT:PSS (poly(3,4-ethylenedioxythiophene): poly(styrene-sulfonate), substituted triaryl amine derivatives, for example, TBD (N,N-dyphenyl-NN-bis(3-methylphenyl)-1,1biphenyl-4,4-diamine) or NBD (N,N-dyphenyl-NN-bis(1-napthylphenyl)-1,1biphenyl-4,4-diamine), [0296] a layer, also referred to as photoactive layer, comprising a p-type and an n-type organic semiconductor, which can exist for example as a p-type/n-type bilayer or as distinct p-type and n-type layers, or as blend or p-type and n-type semiconductor, forming a BHJ, [0297] optionally a layer having electron transport properties, for example comprising LiF, TiO.sub.x, ZnO.sub.x, PFN, a poly(ethyleneimine) or crosslinked nitrogen containing compound derivatives or a phenanthroline derivatives [0298] a low work function electrode, preferably comprising a metal like for example aluminum, serving as cathode,
wherein at least one of the electrodes, preferably the anode, is transparent to visible and/or NIR light, and
wherein the p-type or n-type semiconductor is a compound according to the present invention.

[0299] A second preferred OPV device according to the invention is an inverted OPV device and comprises the following layers (in the sequence from bottom to top): [0300] optionally a substrate, [0301] a high work function metal or metal oxide electrode, comprising for example ITO and FTO, serving as cathode, a layer having hole blocking properties, preferably comprising a metal oxide like TiO.sub.x or ZnO.sub.x, or comprising an organic compound such as polymer like poly(ethyleneimine) or crosslinked nitrogen containing compound derivatives or phenanthroline derivatives, [0302] a photoactive layer comprising a p-type and an n-type organic semiconductor, situated between the electrodes, which can exist for example as a p-type/n-type bilayer or as distinct p-type and n-type layers, or as blend or p-type and n-type semiconductor, forming a BHJ, [0303] an optional conducting polymer layer or hole transport layer, preferably comprising an organic polymer or polymer blend, for example of PEDOT:PSS, nafion or substituted triaryl amine derivatives, for example TBD or NBD, [0304] an electrode comprising a high work function metal like for example silver, serving as anode,
wherein at least one of the electrodes, preferably the cathode, is transparent to visible and/or NIR light, and
wherein the p-type or n-type semiconductor is a compound according to the present invention.

[0305] In the OPV devices of the present invention the p-type and n-type semiconductor materials are preferably selected from the materials, like the compound/polymer or compound/polymer/fullerene systems as described above.

[0306] When the active layer is deposited on the substrate, it forms a BHJ that phase separates at nanoscale level. For discussion on nanoscale phase separation see Dennler et al, Proceedings of the IEEE, 2005, 93 (8), 1429 or Hoppe et al, Adv. Func. Mater, 2004, 14(10), 1005. An optional annealing step may be then necessary to optimize blend morpohology and consequently OPV device performance.

[0307] Another method to optimize device performance is to prepare formulations for the fabrication of OPV(BHJ) devices that may include high boiling point additives to promote phase separation in the right way. 1,8-Octanedithiol, 1,8-diiodooctane, nitrobenzene, 1-chloronaphthalene, N,N-dimethylformamide, dimethylacetamide, dimethylsulfoxide and other additives have been used to obtain high-efficiency solar cells. Examples are disclosed in J. Peet. et al, Nat. Mater., 2007, 6. 497 or Frchet et al. J. Am. Chem. Soc., 2010, 132, 7595-7597.

[0308] Another preferred embodiment of the present invention relates to the use of a compound or composition according to the present invention as dye, hole transport layer, hole blocking layer, electron transport layer and/or electron blocking layer in a DSSC or a perovskite-based solar cells, and to a DSSC or perovskite-based solar cells comprising a compound composition or polymer blend according to the present invention.

[0309] DSSCs and perovskite-based DSSCs can be manufactured as described in the literature, for example in Chem. Rev. 2010, 110, 6595-6663, Angew. Chem. Int. Ed. 2014, 53, 2-15 or in WO2013171520A1

[0310] The compounds and compositions of the present invention are also suitable for use in the semiconducting channel of an OFET. Accordingly, the invention also provides an OFET comprising a gate electrode, an insulating (or gate insulator) layer, a source electrode, a drain electrode and an organic semiconducting channel connecting the source and drain electrodes, wherein the organic semiconducting channel comprises a compound or composition according to the present invention. Other features of the OFET are well known to those skilled in the art.

[0311] OFETs where an OSC material is arranged as a thin film between a gate dielectric and a drain and a source electrode, are generally known, and are described for example in U.S. Pat. Nos. 5,892,244, 5,998,804, 6,723,394 and in the references cited in the background section. Due to the advantages, like low cost production using the solubility properties of the compounds according to the invention and thus the processibility of large surfaces, preferred applications of these FETs are such as integrated circuitry, TFT displays and security applications.

[0312] The gate, source and drain electrodes and the insulating and semiconducting layer in the OFET device may be arranged in any sequence, provided that the source and drain electrode are separated from the gate electrode by the insulating layer, the gate electrode and the semiconductor layer both contact the insulating layer, and the source electrode and the drain electrode both contact the semiconducting layer.

[0313] An OFET device according to the present invention preferably comprises: [0314] a source electrode, [0315] a drain electrode, [0316] a gate electrode, [0317] a semiconducting layer, [0318] one or more gate insulator layers, [0319] optionally a substrate.
wherein the semiconductor layer comprises a compound or composition according to the present invention.

[0320] The OFET device can be a top gate device or a bottom gate device. Suitable structures and manufacturing methods of an OFET device are known to the skilled in the art and are described in the literature, for example in US 2007/0102696 A1.

[0321] The gate insulator layer preferably comprises a fluoropolymer, like e.g. the commercially available Cytop 809M or Cytop 107M (from Asahi Glass). Preferably the gate insulator layer is deposited, e.g. by spin-coating, doctor blading, wire bar coating, spray or dip coating or other known methods, from a formulation comprising an insulator material and one or more solvents with one or more fluoro atoms (fluorosolvents), preferably a perfluorosolvent. A suitable perfluorosolvent is e.g. FC75 (available from Acros, catalogue number 12380). Other suitable fluoropolymers and fluorosolvents are known in prior art, like for example the perfluoropolymers Teflon AF 1600 or 2400 (from DuPont) or Fluoropel (from Cytonix) or the perfluorosolvent FC 43 (Acros, No. 12377). Especially preferred are organic dielectric materials having a low permittivity (or dielectric contant) from 1.0 to 5.0, very preferably from 1.8 to 4.0 (low k materials), as disclosed for example in US 2007/0102696 A1 or U.S. Pat. No. 7,095,044.

[0322] In security applications, OFETs and other devices with semiconducting materials according to the present invention, like transistors or diodes, can be used for RFID tags or security markings to authenticate and prevent counterfeiting of documents of value like banknotes, credit cards or ID cards, national ID documents, licenses or any product with monetry value, like stamps, tickets, shares, cheques etc.

[0323] Alternatively, the compounds and compositions according to the invention can be used in OLEDs, e.g. as the active display material in a flat panel display applications, or as backlight of a flat panel display like e.g. a liquid crystal display. Common OLEDs are realized using multilayer structures. An emission layer is generally sandwiched between one or more electron-transport and/or hole-transport layers. By applying an electric voltage electrons and holes as charge carriers move towards the emissive layer where their recombination leads to the excitation and hence luminescence of the lumophor units contained in the emission layer.

[0324] The compounds and compositions according to the invention can be employed in one or more of a buffer layer, electron or hole transport layer, electron or hole blocking layer and emissive layer, corresponding to their electrical and/or optical properties. Furthermore their use within the emissive layer is especially advantageous, if the compounds according to the invention show electroluminescent properties themselves or comprise electroluminescent groups or compounds. The selection, characterization as well as the processing of suitable monomeric, oligomeric and polymeric compounds or materials for the use in OLEDs is generally known by a person skilled in the art, see, e.g., Mller et al, Synth. Metals, 2000, 111-112, 31-34, Alcala, J. Appl. Phys., 2000, 88, 7124-7128 and the literature cited therein.

[0325] According to another use, the compounds and compositions according to the present invention, especially those showing photoluminescent properties, may be employed as materials of light sources, e.g. in display devices, as described in EP 0 889 350 A1 or by C. Weder et al., Science, 1998, 279, 835-837.

[0326] A further aspect of the invention relates to both the oxidised and reduced form of a compound according to the present invention. Either loss or gain of electrons results in formation of a highly delocalised ionic form, which is of high conductivity. This can occur on exposure to common dopants. Suitable dopants and methods of doping are known to those skilled in the art, e.g. from EP 0 528 662, U.S. Pat. No. 5,198,153 or WO 96/21659.

[0327] The doping process typically implies treatment of the semiconductor material with an oxidating or reducing agent in a redox reaction to form delocalised ionic centres in the material, with the corresponding counterions derived from the applied dopants. Suitable doping methods comprise for example exposure to a doping vapor in the atmospheric pressure or at a reduced pressure, electrochemical doping in a solution containing a dopant, bringing a dopant into contact with the semiconductor material to be thermally diffused, and ion-implantantion of the dopant into the semiconductor material.

[0328] When electrons are used as carriers, suitable dopants are for example halogens (e.g., I.sub.2, Cl.sub.2, Br.sub.2, ICl, ICl.sub.3, IBr and IF), Lewis acids (e.g., PF.sub.5, AsF.sub.5, SbF.sub.5, BF.sub.3, BCl.sub.3, SbCl.sub.5, BBr.sub.3 and SO.sub.3), protonic acids, organic acids, or amino acids (e.g., HF, HCl, HNO.sub.3, H.sub.2SO.sub.4, HClO.sub.4, FSO.sub.3H and ClSO.sub.3H), transition metal compounds (e.g., FeCl.sub.3, FeOCl, Fe(ClO.sub.4).sub.3, Fe(4-CH.sub.3C.sub.6H.sub.4SO.sub.3).sub.3, TiCl.sub.4, ZrCl.sub.4, HfCl.sub.4, NbF.sub.5, NbCl.sub.5, TaCl.sub.5, MoF.sub.5, MoCl.sub.5, WF.sub.5, WCl.sub.6, UF.sub.6 and LnCl.sub.3 (wherein Ln is a lanthanoid), anions (e.g., Cl.sup., Br.sup., I.sup., I.sub.3.sup., HSO.sub.4.sup., SO.sub.4.sup.2, NO.sub.3.sup., ClO.sub.4.sup., BF.sub.4.sup., PF.sub.6.sup., AsF.sub.6.sup., SbF.sub.6.sup., FeCl.sub.4.sup., Fe(CN).sub.6.sup.3, and anions of various sulfonic acids, such as aryl-SO.sub.3.sup.). When holes are used as carriers, examples of dopants are cations (e.g., H.sup.+, Li.sup.+, Na.sup.+, K.sup.+, Rb.sup.+ and Cs.sup.+), alkali metals (e.g., Li, Na, K, Rb, and Cs), alkaline-earth metals (e.g., Ca, Sr, and Ba), O.sub.2, XeOF.sub.4, (NO.sub.2.sup.+) (SbF.sub.6.sup.), (NO.sub.2.sup.+) (SbCl.sub.6.sup.+), (NO.sub.2.sup.+)(BF.sub.4.sup.), AgClO.sub.4, H.sub.2IrCl.sub.6, La(NO.sub.3).sub.3.6H.sub.2O, FSO.sub.2OOSO.sub.2F, Eu, acetylcholine, R.sub.4N.sup.+, (R is an alkyl group), R.sub.4P.sup.+ (R is an alkyl group), R.sub.6As.sup.+ (R is an alkyl group), and R.sub.3S.sup.+ (R is an alkyl group).

[0329] The conducting form of a compound according to the present invention can be used as an organic metal in applications including, but not limited to, charge injection layers and ITO planarising layers in OLED applications, films for flat panel displays and touch screens, antistatic films, printed conductive substrates, patterns or tracts in electronic applications such as printed circuit boards and condensers.

[0330] The compounds and compositions according to the present invention may also be suitable for use in organic plasmon-emitting diodes (OPEDs), as described for example in Koller et al., Nat. Photonics, 2008, 2, 684.

[0331] According to another use, the compounds according to the present invention can be used alone or together with other materials in or as alignment layers in LCD or OLED devices, as described for example in US 2003/0021913. The use of charge transport compounds according to the present invention can increase the electrical conductivity of the alignment layer. When used in an LCD, this increased electrical conductivity can reduce adverse residual dc effects in the switchable LCD cell and suppress image sticking or, for example in ferroelectric LCDs, reduce the residual charge produced by the switching of the spontaneous polarisation charge of the ferroelectric LCs. When used in an OLED device comprising a light emitting material provided onto the alignment layer, this increased electrical conductivity can enhance the electroluminescence of the light emitting material. The compounds according to the present invention having mesogenic or liquid crystalline properties can form oriented anisotropic films as described above, which are especially useful as alignment layers to induce or enhance alignment in a liquid crystal medium provided onto said anisotropic film. The polymers according to the present invention may also be combined with photoisomerisable compounds and/or chromophores for use in or as photoalignment layers, as described in US 2003/0021913 A1.

[0332] According to another use the compounds and compositions according to the present invention, especially their water-soluble derivatives (for example with polar or ionic side groups) or ionically doped forms, can be employed as chemical sensors or materials for detecting and discriminating DNA sequences. Such uses are described for example in L. Chen, D. W. McBranch, H. Wang, R. Helgeson, F. Wudl and D. G. Whitten, Proc. Natl. Acad. Sci. U.S.A., 1999, 96, 12287; D. Wang, X. Gong, P. S. Heeger, F. Rininsland, G. C. Bazan and A. J. Heeger, Proc. Natl. Acad. Sci. U.S.A., 2002, 99, 49; N. DiCesare, M. R. Pinot, K. S. Schanze and J. R. Lakowicz, Langmuir, 2002, 18, 7785; D. T. McQuade, A. E. Pullen, T. M. Swager, Chem. Rev., 2000, 100, 2537.

[0333] Unless the context clearly indicates otherwise, as used herein plural forms of the terms herein are to be construed as including the singular form and vice versa.

[0334] Throughout the description and claims of this specification, the words comprise and contain and variations of the words, for example comprising and comprises, mean including but not limited to, and are not intended to (and do not) exclude other components.

[0335] It will be appreciated that variations to the foregoing embodiments of the invention can be made while still falling within the scope of the invention. Each feature disclosed in this specification, unless stated otherwise, may be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0336] All of the features disclosed in this specification may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. In particular, the preferred features of the invention are applicable to all aspects of the invention and may be used in any combination. Likewise, features described in non-essential combinations may be used separately (not in combination).

[0337] Above and below, unless stated otherwise percentages are percent by weight and temperatures are given in degrees Celsius. Values of the di-electric constant (permittivity) refer to values taken at 20 C. and 1,000 Hz.

[0338] The invention will now be described in more detail by reference to the following examples, which are illustrative only and do not limit the scope of the invention.

Example 1

Dimethyl-6,6-(dithieno[3,2-b:2,3-d]thiophene-2,6-diyl)bis(3-bromobenzoate)

[0339] ##STR00091##

[0340] To a degassed mixture of 2,6-bis(tributylstannyl)dithieno[3,2-b:2,3-d]thiophene (10 g, 12.9 mmol), methyl 5-bromo-2-iodobenzoate (10.1 g, 29.7 mmol) and anhydrous toluene (200 cm.sup.3) was added tri-o-tolyl phosphine (0.1 g, 0.32 mmol) and bis(triphenylphosphine)palladium (II) dichloride (0.12 g, 0.17 mmol). The mixture was further degassed for 10 minutes and then heated at 80 C. for 21 hours. After cooling to 23 C., the reaction mixture was poured into water (250 cm.sup.3) and the organic layer decanted. The organic layer was washed with brine (200 cm.sup.3), dried over anhydrous magnesium sulphate, filtered and the solvent removed in vacuo. The residue was triturated in acetonitrile and the solid collected by filtration. The solid was purified by recrystallisation (acetonitrile:dichloromethane; 1:1) to give 1.5 g of product. Filtrates from the trituration and recrystallisation were combined and purified by silica gel chromatography (dichloromethane:heptanes; 3:2) to give further product. Both portions were combined to give dimethyl-6,6-(dithieno[3,2-b:2,3-d]thiophene-2,6-diyl)bis(3-bromobenzoate) (1.75 g, 40%) as a yellow solid. .sup.1H-NMR (400 MHz, CDCl.sub.3) 7.93 (2H, d, J 2.4), 7.68 (2H, dd, J 2.8, 7.9), 7.43 (2H, d, J 8.3), 7.26 (2H, s), 3.80 (6H, s).

(Dithieno[3,2-b:2,3-d]thiophene-2,6-diylbis(3-bromo-6,1-phenylene))bis(bis(4-hexadecylphenyl)methanol)

[0341] ##STR00092##

[0342] To a mixture of 1-bromo-4-hexadecylbenzene (9.8 g, 25.7 mmol) and anhydrous tetrahydrofuran (140 cm.sup.3) at 65 C. was added n-butyllithium (11 cm.sup.3, 27.5 mmol, 2.5 M in hexanes) dropwise over a period of 20 minutes. The resulting suspension was stirred at 65 C. for 3.5 hours before dimethyl 6,6-(dithieno[3,2-b:2,3-d]thiophene-2,6-diyl)bis(3-bromobenzoate) (3.20 g, 5.1 mmol) was added. The reaction mixture was stirred and warmed slowly over 17 hours to 23 C. Water (100 cm.sup.3) and tert-butyl methyl ether (100 cm.sup.3) were added and the mixture stirred for 30 minutes. The organic layer was decanted and the aqueous layer extracted with tert-butyl methyl ether (350 cm.sup.3). The combined organics dried over anhydrous magnesium sulphate, filtered and the solvent removed in vacuo. The residue purified by silica gel chromatography (heptanes:ethyl acetate; 19:1) to give (dithieno[3,2-b:2,3-d]thiophene-2,6-diylbis(3-bromo-6,1-phenylene))bis(bis(4-hexadecylphenyl)methanol) (6.9 g, 76%) as an orange oil. .sup.1H-NMR (400 MHz, CDCl.sub.3) 7.46 (2H, dd, J 2.3, 8.1), 7.21 (2H, d, J 8.1), 7.05-7.13 (18H, m), 6.16 (2H, s), 3.27 (2H, s), 2.63 (8H, m), 1.63 (8H, m), 1.27-1.34 (104H, m), 0.89 (12H, t, J 6.8).

[0343] Compound 1

##STR00093##

[0344] To a mixture of (dithieno[3,2-b:2,3-d]thiophene-2,6-diylbis(3-bromo-6,1-phenylene))bis(bis(4-hexadecyl phenyl)methanol) (6.9 g, 3.9 mmol) and dichloromethane (180 cm.sup.3) was added p-toluene sulfonic acid (1.48 g, 7.8 mmol) and the reaction mixture heated at reflux for 5 hours. The mixture cooled to 23 C. and the solvent removed in vacuo. The residue purified by silica pad (heptanes) and recrystallisation (2-butanone) to give compound 1 (2.6 g, 38%) as a yellow solid. .sup.1H-NMR (400 MHz, CDCl.sub.3) 7.51 (2H, d, J 1.8), 7.45 (2H, dd, J 1.8, 8.1), 7.31 (2H, d, J 8.1), 2.53 (8H, m), 1.52-1.62 (8H, m), 1.20-1.39 (104H, m), 0.89 (12H, m).

[0345] Polymer 1

##STR00094##

[0346] To mixture of compound 1 (500.0 mg, 0.289 mmol), 2,5-bis-trimethylstannanyl-thieno[3,2-b]thiophene (134.4, 0.289 mmol), tris(dibenzylideneacetone)dipalladium(0) (4.1 mg, 0.0058 mmol), tri-o-tolyl phosphine (7.0 mg, 0.023 mmol), toluene (15.0 cm.sup.3) and N,N-dimethylformamide (3.0 cm.sup.3) was degassed by bubbling nitrogen for 30 minutes. The reaction mixture was then heated at 110 C. under nitrogen in a pre-heated block for 17 hours. Bromobenzene (0.03 cm.sup.2) was added and the mixture heated at 110 C. for 20 minutes. Phenytributyltin (0.19 cm.sup.3) was added and the mixture heated at 110 C. for 20 minutes. The mixture allowed to cool slightly and then precipitated into stirred methanol (150 cm.sup.3). The solid collected by filtration and subjected to Soxhlet extraction: acetone, 40-60 petrol, cyclohexane and chloroform. The chloroform extract was poured into stirred methanol (500 cm.sup.3) and the solid collected by filtration to give polymer 1 (469 mg, 95%) as an orange solid. GPC (chlorobenzene, 50 C.) M.sub.n=21,400 g/mol, M.sub.w=76,900 g/mol.

Example 2

[0347] Compound 2

##STR00095##

[0348] A mixture of 2,6-bis(tributylstannyl)dithieno[3,2-b:2,3-d]thiophene (6.5 g, 8.4 mmol), 2-bromo-3-thiophenecarboxylic acid methyl ester (4.1 g, 18 mmol), tri-o-tolylphosphine (200 mg, 0.67 mmol), N,N-dimethylformamide (30 cm.sup.3) and anhydrous toluene (150 cm.sup.3) was degassed for 25 minutes. Bis(triphenylphosphine)palladium (II) dichloride (118 mg, 0.17 mmol) was added and the mixture stirred at a gentle reflux for 17 hours. The reaction mixture was allowed to cool to 23 C. and poured into methanol (500 cm.sup.3). The precipitate collected by filtration and purified by silica gel chromatography (gradient from 40-60 petrol to dichloromethane) to give compound 2 (1.26 g, 32%) as a yellow solid. .sup.1H-NMR (300 MHz, CDCl.sub.3) 7.75 (2H, s), 7.52 (2H, d, J 5.5), 7.24 (2H, d, J 5.5), 3.87 (6H, s).

[0349] Compound 3

##STR00096##

[0350] To a solution of 1-bromo-4-octylbenzene (3.56 g, 13 mmol) in anhydrous tetrahydrofuran (150 cm.sup.3) at 78 C. was added dropwise n-butyllithium (5.8 cm.sup.3, 15 mmol, 2.5 M in hexanes) over 30 minutes. The solution was then stirred at 78 C. for 1 hour before addition of compound 2 (1.26 g, 2.6 mmol). The mixture was stirred for 5 minutes, the cooling removed and the mixture stirred at 23 C. for 17 hours. Water (50 cm.sup.3) was added to the reaction mixture and the organic was extracted with ether (100 cm.sup.3). The organic layer was dried over anhydrous magnesium sulfate, filtered and the solvent removed in vacuo to give crude compound 3 (3.1 g) as a brown/yellow oil. .sup.1H-NMR (300 MHz, CDCl.sub.3) 7.24-7.29 (2H, m), 7.07-7.21 (16H, m), 6.72 (2H, s), 6.49 (2H, d, J 5.3), 3.22 (2H, s), 2.52-2.64 (8H, m), 1.50-1.66 (8H, m), 1.13-1.39 (40H, m), 0.79-0.93 (12H, m).

[0351] Compound 4

##STR00097##

[0352] To a solution of crude compound 3 (3.1 g, 2.6 mmol) in dichloromethane (100 cm.sup.3) was added p-toluenesulfonic acid (0.91 g, 5.3 mmol), the mixture heated at reflux for 4 hours and at 30 C. for 17 hours. The mixture allowed to cool to 23 C. and passed through a short silica pad (dichloromethane). The residue purified by silica gel chromatography (gradient from 40-60 petrol to 40-60 petrol:dichloromethane; 9:1) to give compound 4 (430 mg, 14%) as a yellow solid. .sup.1H-NMR (300 MHz, CDCl.sub.3) 7.19 (2H, d, J 5.0), 7.09-7.15 (8H, m), 7.19 (2H, d, J 5.0), 6.99-7.04 (8H, m), 2.44-2.58 (8H, m), 1.48-1.62 (8H, m), 1.16-1.37 (40H, m), 0.81-0.92 (12H, m).

[0353] Compound 5

##STR00098##

[0354] To compound 4 (430 mg, 0.38 mmol) in anhydrous tetrahydrofuran (30 cm.sup.3) at 23 C. was added N-bromosuccinimide (138 mg, 0.77 mmol). The reaction mixture was then stirred at 23 C. for 3 hours. Water (50 cm.sup.3) was added and the organics extracted with ether (350 cm.sup.3). The combined organics dried over anhydrous magnesium sulfate, filtered and the solvent removed in vacuo. The residue purified by silica gel chromatography (gradient from 40-60 petrol to 40-60 petrol:dichloromethane; 19:1) to give compound 5 (380 mg, 78%) as a yellow solid. .sup.1H-NMR (300 MHz, CDCl.sub.3) 7.05-7.11 (8H, m), 7.05 (2H, s), 6.99-7.04 (8H, m), 2.47-2.58 (8H, m), 1.49-1.61 (8H, m), 1.18-1.37 (40H, m), 0.82-0.91 (12H, m).

[0355] Polymer 2

##STR00099##

[0356] To a mixture of compound 5 (137.6 mg, 0.106 mmol), 4,7-dibromo-[1,2,5]thiadiazolo[3,4-c]pyridine (125.3 mg, 0.425 mmol), 7,7-bis-(2-ethyl-hexyl)-2,5-bis-trimethylstannanyl-7H-3,4-dithia-7-sila-cyclopenta[a]pentalene (208.5 mg, 0.280 mmol), 7,7-bis-(2-ethyl-hexyl)-2,5-bis-trimethylstannanyl-7H-3,4-dithia-7-germa-cyclopenta[a]pentalene (197.8 mg, 0.251 mmol), tri-o-tolyl phosphine (28 mg, 0.09 mmol) and tris(dibenzylideneacetone)dipalladium(0) (17.7 mg, 0.03 mmol) was added degassed anhydrous toluene (10 cm.sup.3) and the reaction mixture further degassed by bubbling nitrogen for 20 minutes. The mixture heated at 110 C. in a pre-heated block for 17 hours. Bromo-benzene (0.03 cm.sup.3) added and the mixture stirred at 110 C. for 30 minutes followed by addition of phenyltributyltin (0.14 cm.sup.3). The reaction mixture heated at 110 C. for a further 30 minutes. The reaction mixture allowed to cool slightly and poured into stirred methanol (100 cm.sup.3). The solid collected by filtration and subjected to Soxhlet extraction: acetone, 40-60 petrol, 80-100 petrol and cyclohexanes. The cyclohexanes extract was concentrated in vacuo and poured into stirred 2-propanol (200 cm.sup.3) and the polymer precipitate collected by filtration to give polymer 2 (148 mg, 36%) as a black solid. GPC (chlorobenzene, 50 C.) M.sub.n=21,000 g/mol, M.sub.w=47,000 g/mol.

Example 3

[0357] Compound 6

##STR00100##

[0358] To a solution of compound 5 (245 mg, 0.19 mmol) in anhydrous tetrahydrofuran (9 cm.sup.3) at 78 C. was added dropwise n-butyllithium (0.25 cm.sup.3, 0.62 mmol, 2.5 M in hexane) over 20 minutes. After addition, the reaction mixture was stirred at 78 C. for 70 minutes before N,N-dimethylformamide (0.38 cm.sup.3, 4.9 mmol) was added. The mixture was then allowed to warm to 23 C. with stirring over 65 hours. Dichloromethane (30 cm.sup.3) and water (60 cm.sup.3) were added and the organic layer extracted, additionally washing the aqueous layer with dichloromethane (20 cm.sup.3). The combined organic extracts are then washed with water (50 cm.sup.3) and brine (75 cm.sup.3) diluted with water (25 cm.sup.3), extracting the aqueous layer each time with additional dichloromethane (25 cm.sup.3). The combined organic extracts are dried over anhydrous magnesium sulfate, filtered and the solvent removed in vacuo. The crude was partially purified by column chromatography using a graded solvent system (40-60 petrol:dichloromethane; 1:0-1:4) to give compound 6 (68 mg, 30%) as a partially pure yellow/orange solid. 1H NMR (400 MHz, CDCl.sub.3) 9.82 (2H, s), 7.68 (2H, s), 7.09-7.14 (8H, m), 7.03-7.07 (8H, m), 2.54 (8H, t, J 7.9), 1.52-1.61 (8H, m), 1.21-1.36 (40H, m), 0.86-0.89 (12H, m).

[0359] Compound 7

##STR00101##

[0360] To a solution of partially purified compound 6 (68 mg, 0.06 mmol) in anhydrous chloroform (6 cm.sup.3) was added pyridine (0.32 cm.sup.3, 4.0 mmol). The mixture was then degassed with nitrogen before 3-(dicyanomethylidene)indan-1-one (77 mg, 0.40 mmol) was added. The solution was then further degassed for 10 minutes and stirred at 23 C. for 2.5 hours. The reaction mixture was then added to methanol (100 cm.sup.3), washing in with methanol (210 cm.sup.3) and dichloromethane (5 cm.sup.3). The suspension was stirred for 10 minutes before the precipitated solid was collected by vacuum filtration and washed with methanol (310 cm.sup.3). The crude product was then partially purified by column chromatography using a graded solvent system (40-60 petrol:dichloromethane; 1:0-2:3). A portion of the partially purified material is then further purified by preparative TLC (40-60 petrol:dichloromethane; 2:3) to give compound 7 as a blue solid. 1H NMR (400 MHz, CD.sub.2Cl.sub.2) 8.83 (2H, s), 8.63-8.67 (2H, m), 7.88-7.93 (2H, m), 7.70-7.82 (6H, m), 6.92-7.29 (16H, m), 2.56 (8H, t, J 7.8), 0.60-1.84 (60H, m).

Example 4Transistor Fabrication and Measurement

[0361] Top-gate thin-film organic field-effect transistors (OFETs) were fabricated on glass substrates with photolithographically defined Au source-drain electrodes. A 7 mg/cm.sup.3 solution of the organic semiconductor in dichlorobenzene was spin-coated on top (an optional annealing of the film is carried out at 100 C., 150 C. or 200 C. for between 1 and 5 minutes) followed by a spin-coated fluoropolymer dielectric material (Lisicon D139 from Merck, Germany). Finally a photolithographically defined Au gate electrode was deposited. The electrical characterization of the transistor devices was carried out in ambient air atmosphere using computer controlled Agilent 4155C Semiconductor Parameter Analyser. Charge carrier mobility in the saturation regime (.sub.sat) was calculated for the compound. Field-effect mobility was calculated in the saturation regime (V.sub.d>(V.sub.gV.sub.0)) using equation (1):

[00001]$\begin{array}{cc}{\left(\frac{{\mathrm{dI}}_d^{\mathrm{sat}}}{{\mathrm{dV}}_g}\right)}_{V_d}=\frac{{\mathrm{WC}}_i}{L}.Math.{}^{\mathrm{sat}}\left(V_g-V_0\right)& \left(1\right)\end{array}$

where W is the channel width, L the channel length, C.sub.i the capacitance of insulating layer, V.sub.g the gate voltage, V.sub.0 the turn-on voltage, and .sub.sat is the charge carrier mobility in the saturation regime. Turn-on voltage (V.sub.0) was determined as the onset of source-drain current.

[0362] The mobility (.sub.sat) for polymer 1 is 0.06 cm.sup.2/Vs.

Example 5Bulk Heterojunction Organic Photodetector Devices (OPDs)

[0363] Devices are fabricated onto glass substrates with six pre-patterned ITO dots of 5 mm diameter to provide the bottom electrode. The ITO substrates are cleaned using a standard process of ultrasonication in Decon90 solution (30 minutes) followed by washing with de-ionized water (3) and ultrasonication in de-ionized water (30 minutes). The ZnO ETL layer was deposited by spin coating a ZnO nanoparticle dispersion onto the substrate and drying on a hotplate for 10 minutes at a temperature between 100 and 140 C. A formulation of polymer and [6,6]-phenyl-C.sub.71-butyric acid methyl ester (PCBM[C70]) was prepared at a 1:1.5 or a 1:2 ratio in 1,2-dichlorobenzene at a concentration of 20 mg/ml, and stirred for 17 hours at 60 C. The formulation was then filtered through a 0.2 m PTFE filter and the formulation used to coat the active layer. The active layer was deposited using blade coating (K101 Control Coater System from RK). The stage temperature was set to 70 C., the blade gap set between 2-15 m and the speed set between 2-8 m/min targeting a final dry film thickness of 500 nm. Following coating the active layer was annealed at 100 C. for 10 minutes. The MoO.sub.3 HTL layer was deposited by E-beam vacuum deposition from MoO.sub.3 pellets at a rate of 1 /s, targeting 15 nm thickness. Finally, the top silver electrode was deposited by thermal evaporation through a shadow mask, to achieve Ag thickness between 40-80 nm.

[0364] The J-V curves are measured using a Keithley 4200 system under light and dark conditions at a bias from +5 to 5 V. The light source was a 580 nm LED with power 0.5 mW/cm.sup.2.

[0365] The EQE of OPD devices are characterized between 400 and 1100 nm under 2V bias, using an External Quantum Efficiency (EQE) Measurement System from LOT-QuantumDesign Europe. The EQE value at 850 nm for Polymer 2 is 21%.

Examples 6-8: Small Molecules with Terminal Withdrawing Groups

[0366] Molecular structures were optimized at B3LYP/6-31G* level using Firefly QC package (see Alex A. Granovsky, Firefly version 8, www http://classic.chem.msu.su/gran/firefly/index.html), which is partially based on the GAMESS (US) source code (see M. W. Schmidt, K. K. Baldridge, J. A. Boatz, S. T. Elbert, M. S. Gordon, J. H. Jensen, S. Koseki, N. Matsunaga, K. A. Nguyen, S. Su, T. L. Windus, M. Dupuis, J. A. Montgomery J. Comput. Chem. 14, 1347-1363 (1993)).

[0367] E.sub.HOMO and E.sub.LUMO are defined as the eigenvalues of, respectively, the highest occupied and lowest unoccupied Kohn-Sham molecular orbitals, and are used as approximations of, respectively, ionisation potential (IP) and electron affinity (EA). E.sub.g is defined as |E.sub.LUMO-E.sub.HOMO| and is the transport band gap of the material. S.sup.0-S.sup.1 is the vertical excitation energy from the ground state S.sup.0 to the first singlet excited state S.sup.1, and is used as the measure of the optical band gap E.sub.g(opt).

[0368] An approximate relation between E.sub.HOMO, E.sub.LUMO and E.sub.g of donor and acceptor materials in a bulk-heterojunction is known as the Scharber model [M. C. Scharber, D. Mhlbacher, M. Koppe, P. Denk, C. Waldauf, A. J. Heeger, C. J. Brabec, Adv. Mater. 2006, 18, 789-794]. It is widely accepted that when the donor material of the donor-acceptor blend absorbs light and forms an excited state, the excited electron must hop onto the neighbouring acceptor site in order for the free carriers to be formed. The driving force of this process is the energetic difference between the excited state of the donor material and the electron affinity (approximated by E.sub.LUMO) of the acceptor material and has been empirically found to be at least ca. 0.35 eV for charge generation to be efficient [D. Veldman, S. C. J. Meskers, R. A. J. Janssen, Adv. Funct. Mater. 2009, 19, 1939-1948; M. C. Scharber, N. S. Sariciftci, Progr. Polym. Sci. 38 (2013) 1929-1940]. Therefore, tuning of acceptor's E.sub.LUMO is of paramount importance, lowering its value will increase the driving force for charge generation and may allow using lower-bandgap donor material, whilst increasing E.sub.LUMO may hinder charge generation. For the present OSC materials, owing to their small optical band gap, another mechanism is also possible: light absorption by the acceptor followed by hole injection to the donor material, driven by the energy difference between E.sub.HOMO of donor and acceptor, respectively [W. Zhao, D. Qian, S. Zhang, S. Li, O. Ingans, F. Gao, J. Hou, Adv. Mater. 2016, DOI: 10.1002/adma.201600281]. This mechanism is responsible for non-negligible external quantum efficiency beyond the absorption edge of the donor material, and retaining of this advantage of the acceptor material requires careful tuning of HOMO energy.

Comparative Example 1

[0369] Compound C1 as shown below is calculated as a reference.

TABLE-US-00003 E.sub.HOMO/ E.sub.LUMO/ E.sub.g/ S.sup.0-S.sup.1/ No. Structure eV eV eV eV C1 [00102] 5.54 3.41 2.13 1.86

Examples 6-8

[0370] The computed values of E.sub.HOMO, E.sub.LUMO, E.sub.g and S.sup.0-S.sup.1 of compound C1 (whilst being different from experimentally determined IP, EA and E.sub.g) are compared with the computed values of compounds 6-8 of formula VI.

TABLE-US-00004 E.sub.HOMO/ E.sub.LUMO/ E.sub.g/ S.sup.0-S.sup.1/ No. Structure eV eV eV eV 6 [00103] 5.46 3.31 2.15 1.86 7 [00104] 5.58 3.40 2.18 1.88 8 [00105] 5.61 3.37 2.24 1.80

[0371] The E.sub.LUMO of compounds 6-8 are found to be close or slightly lower to that of compound C1, indicating a similar or slightly stronger electron affinity. Calculated band gaps of compounds 6-8 are similar or slightly smaller than that of C1.