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

Abstract

Abstract Triplet absorption spectra, extinction coefficients (ɛ T ), decay rates ( K 1 ), oxygen quenching rates (k q ) and intersystem crossing yields (φ T ) 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 ɛ T and φ T 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.