Patent ID: 8003801

Claim:
A compound that corresponds in structure to Formula A-1, A-2, A-3 or A-4 wherein R A is an aromatic ring having the structure wherein the depicted five-membered ring is aromatic and contains at least two ring atoms that are other than carbon, each of X 1 , X 2 and X 3 is independently S, NR 1 , N, CH, or CR 2 , R 1 is C 1 -C 8 -hydrocarbyl or methylene-C 1 -C 8 -hydrocarbylether, and R 2 is selected from the group consisting of C 1 -C 8 -hydrocarbyl, O—C 1 -C 8 -hydrocarbyl, halo, S—C 1 -C 8 -hydrocarbyl, methylenethio-C 1 -C 8 -hydrocarbyl and methylenethio-C 1 -C 8 -acyl, with the proviso that when X 2 is S and X 3 is CR 2 , R 2 is other than C 1 -C 8 -hydrocarbyl, O—C 1 -C 8 -hydrocarbyl or S—C 1 -C 8 -hydrocarbyl; when X 1 is CH and X 2 is NR 1 , X 3 is other than CH or CR 2 ; when X 1 is NR 1 and X 2 is CH, X 3 is other than CR 2 ; when X 1 is CH and X 2 is N, X 3 is other than CH or CR 2 wherein R 2 is CH 3 .