| abstract |
A cyanine compound is represented by formula (I): n n n n n n n n n n A 1 : benzene or naphthalene ring. A 3 : 5- or 6-membered ring. R 1 , R 2 : hydrogen atom and the like. R 7 : an alkyl group and the like. R 12 : a substituent by formula (II) or (II′). R 20 : a hydrogen atom and the like. An q- : a q-valent anion. q: 1 or 2; p: a coefficient for neutral charge. In formula (II): bond between L and T is a double, conjugated double, or triple bond. L: carbon atom. T: carbon, oxygen, sulfur, or nitrogen atom. x, y, z: 0 or 1. s: 0-4. R 13 : hydrogen atom and the like. R 14 , R 15 , and R 16 : hydrogen atom and the like. In formula (II′), the bond between L′ and T′ is a double or conjugated double bond. L′: carbon atom. T′: n n n n n n n n n n carbon, oxygen, nitrogen atom. s′: 0-4. Ring containing L′ and T′: 5-membered ring, may contain a heteroatom. |