Patent ID: 7230070

Claim:
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 Formulae I and I(a) and the at least one second monomeric unit is selected from 6-membered-ring heteroaromatic groups having Formula III where: in each of Formulae I and III: 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 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 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 III: 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 XII: R 2 is selected from hydrogen, alkyl, aryl, heteroalkyl and heteroaryl; δ is 0 or an integer from 1 to 12; with the proviso that: when R in formula III is hydrogen, alkyl, F, —CN, —OR 1 , or CO 2 R 1 the copolymer further comprises end-capping groups that are aromatic.