| abstract |
[PROBLEMS] To develop a novel compound suitable for a photochemotherapeutic agent which can utilize light in the infrared region and has excellent water solubility. SOLUTION: The following formula (1): (Rings A and B may have a substituent, and R1 to R 8 is a sulfonic acid group-containing substituent having 1 to 20 carbon atoms or a carboxyl group-containing substituent having 2 to 20 carbon atoms, and the rest is a hydrogen atom or (C1 to C8) M is an integer of 1 or 2, n is an integer of 0 to 7 or 1/2, and X represents an anion or a cation necessary for neutralizing an intramolecular charge. An aminium-based compound represented by the formula: |