Diimines self-quenching

An important aspect of the photophysics of the Pt(diimine)(dithiolate) photochemistry that has received increasing attention is the ability of the excited-state complexes to undergo self-quenching. Initial work by Connick and Gray (111) showed that the lifetime of the complex Pt(bpy)(bdt) (bdt = benzene-1,2-dithiolate, 31) decreased with increasing solution concentration. The bimolecular self-quenching rate constant, calculated from a Stem-Volmer quenching analysis, was found to be 9.5 x 109 A/-1 s-1 in acetonitrile and 4 x 109 M 1 s 1 in chloroform. However, no evidence of excimer formation... 

---