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)(3)(py)](+) (I) and [Re(bpy)(CO)(3)(ind))](+) (II) in acetonitrile solution is facile and luminescence quenching constants, k(q), are in the range 10(5)-10(8) M(-1)s(-1). 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(q) 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. © Springer Science+Business Media, LLC 2011