Patent ID: 7026029

Claim:
A compound of formula I: wherein Y is O, S, Se, CR 17 R 18 , NR 13 , wherein R 13 , R 17 , R 18 is each independently selected from hydrogen, C 1 -C 3 alkyl and substituted aryl groups and unsubstituted aryl groups; R 2 , R 5 , R 6 , and R 9 each is independently selected from hydrogen, halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, aryl, nitro, azo and fused aromatic groups; R 3 , R 4 R 7 , and R 8 each is independently selected from NR 10 R 11 , OR 12 , hydrogen, alkyl, aryl, azo, and fused aromatic groups; and R 10 , R 11 , R 12 , R 14 , R 15 and R 16 each is independently selected from hydrogen, unsubstituted C 1 C 6 alkyl, substituted C 1 -C 6 alkyl, unsubstituted C 1 -C 6 alkoxy, and substituted C 1 -C 6 alkoxy, benzyl or aryl groups.