| abstract |
A compound represented by the following general formula (I) is disclosed. [Formula 5] [In formula (1), A represents an alkyl group which may have a substituent or the like or a group represented by the following formula (Ia), [Formula 6] R 1 is -COO - or represents a -COOH, R 2 ~ R 11 are each independently, -H, -OH, -COO -, -COOH, -NO 2, -NO, -CN, -SO 3 -, -SO 3 H, -SH, an amino group, an alkyl group, etc. represent various groups, and R 2 to R 5 , R 7 to R 11 may be bonded to each other to form a ring, and X is a non-coloring cation Represents, and k represents the integer of 1-6.] |