Photochemistry of copper(II) chlorocomplexes in acetonitrile: Trapping the ligand-to-metal charge transfer excited state relaxations pathways

• DOI: 10.1016/j.cplett.2014.10.016
• Publication Date: 2014-10-14T19:02:25Z
• Authors: Andrey S. Mereshc...; Pavel K. Olshin; Artur M. Karimov; Mikhail Yu. Skripkin; Kim A. Burkov; Yury S. Tveryanovich; Alexander N. Tarn...
• Keywords: Flash photolysis

Abstract Photochemistry of [Cu(MeCN)3Cl]+, [Cu(MeCN)Cl3]−, and [CuCl4]2− copper(II) chlorocomplexes in acetonitrile solution is studied by means of the combination of the steady-state photolysis and ultrafast transient absorption methods. The main relaxation pathways of the initially excited ligand-to-metal charge transfer states are internal conversion to the ground state, ionic dissociation without (photo)reduction of copper(II), and radical dissociation with (photo)reduction of copper(II). The copper(II)-to-copper(I) photoreduction quantum yields obtained from steady-state photolysis correlate with ultrafast spectroscopy data. The presence of oxygen does not affect the photoreduction quantum yields, which do not exceed 7% for the complexes studied and decrease in the series: [Cu(MeCN)3Cl]+ > [Cu(MeCN)Cl3]− > [CuCl4]2−.