THIAPYRYLIUM SALT-SENSITIZED ELECTRON-TRANSFER REACTIONS OF TRANS-STILBENE, DIMERIZATION AND OXYGENATION

Photoinduced electron transfer reactions of trans-stilbene sensitized by 2,4,6-triphenylthiapyrylium tetrafluoroborate (STPP) were carried o ut by steady-state and laser flash pohtolysis techniques in the presen ce and absence of oxygen in dichloromethane. Rapid dimerization of the trans stilbene cation radical with its neutral species was observed, as previously observed in 2,4,6-triphenylpyrylium tetrafluoroborate (T PP)-sensitized reactions in dichloromethane. Electrochemical and photo physical properties such as fluorescence quantum yield and T-T absorpt ion spectrum of STPP were also studied, and the results were compared with those for TPP. The properties of STPP as an electron transfer sen sitizer are discussed. (C) 1997 John Wiley & Sons, Ltd.