Tetraphenylporphyrin derivative and composition comprising the same

摘要

Wherein R 1, R 2, R 3 and R 4 are, independently of one another, a group of the formula (I) wherein at least one of R 1 to R 4 is a group of the formula: Is a group represented by the following formula: or a salt thereof, and its use as a photosensitizer.