EPR STUDY ON THE CHEMISTRY AND PHOTOCHEMISTRY OF COPPER(II) DITHIOCARBAMATE MIXED-LIGAND COMPLEXES

The thermal and photochemical reactions of the 1 : 1 mixed-ligand comp lexes Cu(dtc)X (X = Cl-, NO3-, ClO4-) have been studied on the ground of their EPR spectra in acetone, CCl4/i-PrOH (1 : 1), and CHCl4/i-PrOH (1 : 1) solutions. The study allows us to get some insight into the b ehaviour of the mixed-ligand Cu-II(dtc)X complexes with respect to the acceptor properties of halocarbons. In CCl4/i-PrOH (1 : 1) both Cu-II (dtc)(+)...NO3- and Cu-II(dtc)(+)...ClO4- undergo thermal reactions wi thin their donor-acceptor complexes with CCl4 to yield Cu(dtc)Cl. On t he time scale of the experiment the reaction does not occur thermally in CHCl3/i-PrOH (1 : 1), but occurs photochemically in both halocarbon /i-PrOH (1 : 1) systems in which Cu(dtc)Cl is further photolyzed to Cu Cl2. Continuous photolysis of the title compounds in acetone simply bl eaches the solution without any intermediate EPR or light absorption.