Nanosecond laser flash photolysis was used to study the mechanism of photochemical transformations of the diethyldithiocarbamate Cu(II) complex (Cu(dtc)(2), where dtc(-) (-)S(2)CNBt(2) 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)(dtcCHCl(2))], complex, where a dtcCHCl(2) molecule is coordinated with a copper ion via one sulfur atom. In the fast reaction (k = 2.1 X 10(9) M-1 s(-1)) with Cu(dtc)(2), this complex forms a long-lived dieter [ClCu(dtc)(dtcCHCl(2))Cu(dtc)(2)]. This intermediate decays during several seconds (k = 5.6 X 10(-2) s(-1)) into the final product, i.e., a diamagnetic diner [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.