TRIPLET-STATE AND PHOTOLYSIS OF S-PHENYL 1-THIONAPHTHOATE

Energy transfer between S-phenyl 1-thionaphthoate (1-SPTN) and several triplet-state energy donors and accepters were studied by transient a bsorption spectra. The results indicate that the energy transfer can o ccur efficiently either from energy donors to 1-SPTN or from 1-SPTN to energy accepters. The energy transfer rate constant of xanthene to 1- SPTN is 1.4 x 10(10) s(-1) mol(-1) dm(3). This means that the energy t ransfer process is diffusion controlled. The triplet-state energy of 1 -SPTN is about 252 kJ mol(-1), estimated from the energy transfer proc esses and the phosphorescence emission. Photolysis of 1-SPTN results i n two main products: diphenyldisulphide and 1,1'-binaphthyl. The photo lysis proceeds via the triplet state mainly, as proved by external mag netic effect.