Photoluminescence Electron-Transfer Quenching of Rhenium(I) Complexes with Organic Sulfides.

Electron-transfer(ET) from organic sulfides to excited state rhenium(I)-based heteroleptic tricarbonyl complexes [Re(bpy)(CO)(py)] ( I) and [Re(bpy)(CO)(ind))] ( II) in acetonitrile solution is facile and luminescence quenching constants, k, are in the range 10-10 Ms. The detection of the sulfide radical cation in this system using time-resolved absorption spectroscopy is a direct evidence for the ET nature of the reaction. The k values for the quenching of Re(I)-complexes with organic sulfides are analyzed with a scheme involving rate controlling electron transfer process. The measured rate constants for the electron transfer (ET) reaction are close to the values calculated from Marcus theory. [ABSTRACT FROM AUTHOR]