Electroactive fluorene copolymers and devices made with such polymers

1. A copolymer consisting essentially of at least one first monomeric unit and at least one second monomeric unit, wherein the at least one first monomeric unit has a Formula I and I(a)

and the at least one second monomeric unit is selected from fused ring aromatic groups having Formula VI,

where:

in each of Formulae I, I(a), VI, VII, and VIII:

R is a substituent on a carbon atom which can be the same or different at each occurrence and is selected from hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, F, —CN, —OR 1 , —CO 2 R 1 , —C ψ H θ F λ , —OC ψ H θ F λ , —SR 1 , —N(R 1 ) 2 , —P(R 1 ) 2 , —SOR 1 , —SO 2 R 1 , —NO 2 , and beta-dicarbonyls having Formula XII

 wherein

R 2 is selected from hydrogen, alkyl, aryl, heteroalkyl and heteroaryl;

δ is 0 or an integer from 1 to 12, adjacent R groups together can form a single 5- or 6-membered cycloalkyl, aryl, or heteroaryl ring,

such that:

R 1 is a substituent on a heteroatom which can be the same or different at each occurrence and is selected from alkyl, aryl, heteroalkyl and heteroaryl; and

ψ is an integer between 1 and 20, and θ and λ and are integers satisfying Equation A1 below:

θ+λ=2ψ+1;  (Equation A1);

in each of Formulae VI, VII, and VIII:

E can be the same or different at each occurrence and is a single bond or a linking group selected from arylene and heteroarylene;

in Formula VI;

the two E's are in the 1,4-, 1,5-, 1,8-, 2,3-, or 2,6- positions;

in Formula VII;

the two E's are in the 1,4-, 1,5-, 1,8-, 2,3-, 2,6-, or 9,10- positions;

in Formula VIII;

a first E is in the 1, 2, or 3 position, a second E is in the 6, 7, or 8 position; and

with the proviso that when R in formulae VI, VII, and VIII is hydrogen, alkyl, F, —CN, —OR 1 , or CO 2 R 1 the copolymer further comprises end-capping groups that are aromatic;

and with the further proviso that said copolymer does not consist of 9,9-di-n-octylfluorene and unsubstituted naphthalene alternating copolymer.

2. The copolymer of claim 1 , wherein R groups in one or more of the at least one first monomeric unit are independently selected from alkyl groups having 1 to 30 carbon atoms; heteroalkyl groups having 1–30 carbon atoms and one or more heteroatoms of S, N, or O; aryl groups having from 6 to 20 carbon atoms, and heteroaryl groups having from 2 to 20 carbon atoms and one or more heteroatoms of S, N, or O.

3. The copolymer of claim 1 that excludes any vinylene monomeric units.

4. The copolymer of claim 1 wherein each R group in each of Formula I, Formula 1(a), Formula VI, Formula VII, and Formula VIII is selected from:

hydrogen;

alkyl;

aryl;

heteroalkyl;

heteroaryl;

F;

—CN;

—P(R 1 ) 2 and —SOR 1 , where R 1 is a substituent on a heteroatom which can be the same or different at each occurrence and is selected from alkyl, aryl, heteroalkyl and heteroaryl;

—NO 2 ;

a beta-dicarbonyl having Formula XII;

—C ψ H θ F λ ;

—OC ψ H θ F λ ; —OR 1 , —CO 2 R 1 , —SR 1 , —N(R 1 ) 2 , and —SO 2 R 1 where R 1 is a straight chain or branched alkyl of more than 20 carbons or a straight chain or branched heteroalkyl.

5. The copolymer of claim 1 wherein the at least one of the R groups in one or more of the at least one first monomeric unit is independently selected from linear and branched n-butyl groups; linear and branched iso-butyl groups; linear and branched pentyl groups; hexyl groups, and octyl groups with and without olefinic unsaturation; phenyl groups, thiophene groups, carbazole groups, alkoxy groups, phenoxy groups and cyano groups.

6. The copolymer of claim 1 wherein at least one of the R groups in one or more of the at least one first monomeric unit are independently selected from H, C 6 –C 12 alkoxy, phenoxy, C 6 –C 12 alkyl, phenyl and cyano.

7. The copolymer of claim 1 wherein one or more of the at least one second monomeric unit is selected from Formulae VI(a) through VI(d), and VII(a)

8. The copolymer of claim 1 , wherein one or more of the at least one second monomeric unit has Formula VI, VII and VIII: wherein R is selected from:

partially or fully fluorinated alkyl groups having from 1 to 12 carbon atoms;

alkoxy groups having from 1 to 12 carbon atoms;

esters having from 3 to 15 carbon atoms;

—SR 1 , —N(R 1 ) 2 , —P(R 1 ) 2 , —SOR 1 , —SO 2 R 1 , where R 1 is an alkyl group having from 1 to 12 carbon atoms;

—NO 2 ; and

beta-dicarbonyls having Formula XII

 where:

in formula XII:

R 2 is an alkyl group having from 1 to 12 carbon atoms and δ is 0, 1, or 2.

9. The copolymer of claim 1 , wherein one or more of the at least one second monomeric unit has one of Formulae VI through VIII wherein:

R groups are H, C 6 –C 12 alkyl groups, C 6 –C 20 aryl groups, and C 2 –C 20 heteroaryl groups; and

in Formula VI:

the E's are in the 1,4-, 1,5-, 1,8-, 2,3-, or 2,6- positions;

in Formula VII:

the E's are in the 1,4-, 1,5-, 1,8-, 2,3-, 2,6-, or 9,10- positions.

10. An electronic device comprising at least one electroactive layer comprising the copolymer of claim 1 .

11. The device of claim 10 , wherein the device comprises a hole injection/transport layer comprising the copolymer of claim 1 .

12. The device of claim 10 , wherein the device comprises an electron injection/transport layer comprising the copolymer of claim 1 .

13. The device of claim 10 wherein the electroactive layer comprises a light-emitting material comprising the copolymer of claim 1 .

14. The device of claim 10 wherein the device is selected from a light-emitting device, a photodetector, and a photovoltaic device.

15. The device of claim 10 wherein the device is an electroluminescent display.

16. A light-emitting device comprising at least one light-emitting layer comprising the copolymer consisting essentially of

at least one first monomeric unit and at least one second monomeric unit, wherein the at least one first monomeric unit has a Formula I and I(a)

 and the at least one second monomeric unit is selected from fused ring aromatic groups having Formula VI,

 where:

in each of Formulae I, I(a), VI, VII, VIII through XI:

R is a substituent on a carbon atom which can be the same or different at each occurrence and is selected from hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, F, —CN, —OR 1 , —CO 2 R 1 , —C ψ H θ F λ , —OC ψ H θ F λ , —SR 1 , —N(R 1 ) 2 , —P(R 1 ) 2 , —SOR 1 , —SO 2 R 1 , —NO 2 , and beta-dicarbonyls having Formula XII

 wherein

R 2 is selected from hydrogen, alkyl, aryl, heteroalkyl and heteroaryl;

δ is 0 or an integer from 1 to 12 and adjacent R groups together can form a single 5- or 6-membered cycloalkyl, aryl, or heteroaryl ring, such that:

R 1 is a substituent on a heteroatom which can be the same or different at each occurrence and is selected from alkyl, aryl, heteroalkyl and heteroaryl; and

ψ is an integer between 1 and 20, and θ and λ are integers satisfying Equation A1 below:

θ+λ=2ψ+1;  (Equation A1);

in each of Formulae VI, VII, VIII, and XI:

E can be the same or different at each occurrence and is a single band or a linking group selected from arylene and heteroarylene;

in Formula VI:

the two E's are in the 1,4-, 1,5-, 1,8-, 2,3-, or 2,6- positions;

in Formula VII;

the two E's are in the 1,4-, 1,5-, 1,8-, 2,3-, 2,6-, or 9,10- positions;

in Formula VIII;

a first E is in the 1, 2, or 3 position, a second E is in the 6, 7, or 8 position;

in Formula IX; and

a first E is in the 2, 3, or 4 position; a second E is in the 7, 8, or 9 position; and

in Formula XII;

with the proviso that said copolymer does not consist of 9,9-di-n-octylfluorene and unsubstituted naphthalene alternating copolymer.