SOME PHOTOPHYSICAL PROPERTIES OF 3-CARBETHOXYPSORALEN, 8-METHOXYPSORALEN and 5-METHOXYPSORALEN TRIPLET STATES

Triplet absorption spectra, extinction coefficients (ɛT), decay rates (K1), oxygen quenching rates (kq) and intersystem crossing yields (φT) for 3-carbethoxypsoralen (3-CPs). 8-methoxypsoralcn (8-MOP) and 5-methoxypsoralen (5-MOP) in methanol are reported. For 8-MOP and 3-CPs corresponding values are also reported with water as the solvent. Some photophysical data are also reported for 5-MOP in water, but ɛT and φT were not obtained. The phosphorescence spectra for these furocoumarin derivatives in ethanol at 77 K are reported together with the corresponding lowest triplet energy and lifetime. The values of the various photophysical properties obtained are compared with values reported by previous workers.