Electroactive fluorene copolymers and devices made with such polymers
The present invention is generally directed to copolymers of fluorene. It further relates to devices that are made with the copolymers.
1. A copolymer comprising at least one first monomeric unit and at least one second monomeric unit, wherein the at least one first monomeric unit has Formula I or Ia and the at least one second monomeric unit is selected from fused ring aromatic groups having Formulae IX trough Formula XI,
where:
in each of Formulae I and IX through XI:
R is a substituent on a carbon atom which can be the same or different at each occurence 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
and as further described below under “Formula XII”; or
adjacent R groups together can form a 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 Formula IX:
E can be the same or different at each occurrence and is a single bond or a linking group selected from arylene and heteroarylene; and
a first E is in the 2, 3, or 4 position; on a second E is in the 7, 8, or 9 position; and
in Formula XII:
R 2 is selected from hydrogen, alkyl, aryl, heteroalkyl and heteroaryl;
δ is 0 or an integer from 1 to 12.
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 heteroatomas 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 1 , Formula IX, Formula X, and Formula XI 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 Fonnula XII;
—C ψ H θF 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 group; carbazole groups, alkoxy groups, phenoxy groups and cyano groups.
6. The copolyrner 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 has one of Formulae IX through XI wherein:
R groups are selectd from H, C 6 –C 12 alkyl groups, C 6 –C 20 aryl groups, and C 2 –C 20 heteroaryl groups.
8. An electronic device comprising at least one electroactive layer comprising the copolymer of claim 1 .
9. The device of claim 8 , wherein the device comprises a hole injection/transport layer comprising the copolymer of claim 1 .
10. The device of claim 8 , wherein the device comprises an electron injection/transport layer comprising the copolymer of claim 1 .
11. The device of claim 8 , wherein the electroactive layer comprises a light-emitting material comprising the copolymer of claim 1 .
12. The copolymer of claim 1 , further comprising end-capping groups comprising an aromatic group.
13. The device of claim 8 , wherein the device is selected from a light-emitting device, a photodetector, and a photovoltaic device.
14. The device of claim 8 , wherein the device is an electroluminescent display.