Patent ID: 8431708

Claim:
A compound of formula (I): wherein each of A and B, independently, is heteroaryl containing at least one nitrogen atom; each of X and Y, independently, is CH or N; each of R 1 -R 6 is H; R 7 is C 2 -C 16 alkyl, C 2 -C 16 alkenyl, or C 2 H 4 —(ZC 2 H 4 ) v —, Z being O, S, or Se and v being 1, 2, or 3; R 8 is C 3 -C 8 heterocycloalkyl containing a nitrogen atom, C 3 -C 8 heterocycloalkyl substituted by an amino group, or C 3 -C 8 cycloalkyl substituted by an amino group; and each of m and n, independently, is 1, 2, or 3.