Photochemistry of Dithiocarbamate Cu(S2CNEt2)2 Complex in CHCl3. Transient Species and TD-DFT Calculations

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2016-10, Vol.120 (40), p.7873-7880
• Main Authors: Solovyev, Aleksey I, Plyusnin, Victor F, Shubin, Aleksandr A, Grivin, Vjacheslav P, Larionov, Stanislav V
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/acs.jpca.6b08738

Nanosecond laser flash photolysis was used to study the mechanism of photochemical transformations of the diethyldithiocarbamate Cu­(II) complex (Cu­(dtc)2, where dtc– ≡ –S2CNEt2 anion) in chloroform solutions. The electron transfer from the excited Cu­(dtc)2 complex to a solvent molecule leads to the appearance of the primary intermediate, the [ClCu­(dtc)­(dtcCHCl2)] complex, where a dtcCHCl2 molecule is coordinated with a copper ion via one sulfur atom. In the fast reaction (k = 2.1 × 109 M–1 s–1) with Cu­(dtc)2, this complex forms a long-lived dimer [ClCu­(dtc)­(dtcCHCl2)­Cu­(dtc)2]. This intermediate decays during several seconds (k = 5.6 × 10–2 s–1) into the final product, i.e., a diamagnetic dimer [ClCu­(dtc)­Cu­(dtc)2]. To determine the structure of intermediate complexes the quantum chemical calculations were carried out using DFT, TD-DFT, and PCM (Polarizable Continuum Model) methods.