Evidence for static quenching of MLCT excited states by iodide.

摘要: The metal-to-ligand charge-transfer (MLCT) excited states of Ru(deeb)(bpy)2(PF6)2 [where bpy is 2,2-bipyridine and deeb 4,4‘-(CO2CH2CH3)2-2,2‘-bipyridine] in acetonitrile or dichloromethane were found to be quenched by iodide at room temperature. ionic strength dependence the optical spectra gave evidence for ion pairing. Iodide quench photoluminescence (PL) intensity influence spectral distribution emitted light. A static component time-resolved PL quenching provided further ground-state adduct. Stern−Volmer analysis an estimate iodide−Ru(deeb)(bpy)22+ adduct equilibrium constant dichloromethane, Ksv = 40 000 M-1. Transient absorption studies clearly demonstrate that electron-transfer mechanism operative I2-• can photoproduced high yield, φ 0.25. For Ru(bpy)3(PF6)2 acetonitrile, similar behavior could observed concentrations >100 times required ...