Patent ID: 8168282

Claim:
A trimethine cyanine compound represented by the formula (1): wherein: Q 1 , Q 2 , Q 3 , and Q 4 are the same or different and each represents a substituted or unsubstituted benzene ring or naphthalene ring; P 1 is a hydrogen atom or an organic group having 1 to 18 carbon atoms; A 1 and A 2 are the same or different and each represents groups of formula CR 3 R 4 , NR 5 , an oxygen atom, or a sulfur atom; Y 1 , Y 2 , Y 3 , and Y 4 are the same or different and each represents an organic group having 1 to 18 carbon atoms; T 1 and T 2 are the same or different and each represents a substituted or unsubstituted benzyl group, a substituted or unsubstituted allyl group, or a substituted or unsubstituted propargyl group; R 1 , R 2 , R 3 , R 4 , and R 5 are the same or different and each represents a hydrocarbon group having 1-18 carbon atoms, which is substituted or unsubstituted; or R 3 and R 4 is bonded together to form a 3- to 6-member carbon ring which is further optionally fused with a benzene ring; X m− represents a counterion having m valence; m represents an integral of 1, 2, or 3; q represents a coefficient for maintaining charge neutrality.