Photophysical properties, singlet oxygen generation and DNA binding affinity of Tris(4-pyridyl)corrole and its phosphorous, gallium and tin complexes

The photophysical properties of a series of pyridyl corroles were reported. Their excited-state dynamics were investigated by femtosecond transient absorption, which revealed a very fast intersystem crossing in the tin complex (3.9 x 10(9) s(-1)) with a high triplet yield of 0.91. An accelerated vibrational cooling of free-base corrole in DMF was observed due to deprotonation. The ability of these corroles to generate singlet oxygen was also quantitatively measured, which demonstrated the tin complex as a promising photosensitizer. The photo-induced reactive oxygen species (ROS) were detected by EPR. Additionally, the DNA binding affinity of these corroles was evaluated to inspect their potential biological use.