Patent ID: 8759534

Claim:
A trimethine cyanine compound represented by the following 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; A 1 and A 2 are the same or different and each represents a group of formulae 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; 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; alternatively R 3 and R 4 can form a 3- to 6-member carbon ring which can further be fused with a benzene ring; B is a divalent linking group represented by the following formula (a) or (b): wherein: P 1 and P 2 are the same or different and each represents a hydrogen atom or an organic group having 1 to 8 carbon atoms; alternatively P 1 and P 2 can form a 3- to 6-member carbon ring which can further be fused with a benzene ring; wherein: E is an oxygen atom, a sulfur atom, R 6 , R 7 and R 8 each represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms; alternatively R 6 and R 7 can form a 3- to 6-member carbon ring; X m− represents an anion having m valence; m represents an integral of 1, 2, or 3; q represents the number attributing the compound with electronic neutrality.