Patent ID: 7220820

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 5-membered-ring heteroaromatic groups having Formula IV in each of Formulae I and IV: 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 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= ψ +1; (Equation A1); in Formula IV: 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 IV: A is independently at each occurrence C or N and γ is 0 or an integer selected from 1 or 2, such that when both A are N, then γ is 0; or when one of A is N and one of A is C, then γ is 1; or when both A are C, then γ is 2; Q is O, S, SO 2 , or NR 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; in Formula XII: R 2 is selected from hydrogen, alkyl, aryl, heteroalkyl and heteroaryl; δ is 0 or an integer from 1 to 12, and when R in formula IV is hydrogen, alkyl, F, —CN, —OR 1 , or CO 2 R 1 the copolymer further comprises end-capping groups that are aromatic.