Charge-transfer photochemistry of bis(diethyl-diselenocarbamato)copper(II).
The photochemical reactions of bis(diethyl-diselenocarbamato)copper(II), Cu(Et2dsc)2, complex have been studied in toluene, CH2Cl2, CHCl3 and chloroalkane/EtOH mixed solvents. Charge-transfer irradiation induces intramolecular oxidation of the ligand and reduction of copper(II) to copper(I) as evidenced by EPR and UV-Vis spectra of the complex as well as quantum yield results. When photolysis is carried out in CHCl3 or CH2Cl2 or in the solvent mixture CHCl3/EtOH resp. CH2Cl2/EtOH of lower than 1:1 EtOH content, the primary photoproduct CuI(Et2dsc) is further oxidised in a dark reaction with the chloroalkane producing the corresponding paramagnetic mixed-ligand CuII(Et2dsc)Cl complex in equilibrium with its chloride-bridged and EPR silent, dimeric form Cu2(Et2dsc)2Cl2. At low concentration of EtOH the equilibrium is shifted to the dimeric form whereas at higher than 1:1 EtOH content in the mixed solvent CHCl3/EtOH it is shifted to CuII(Et2dsc)Cl. A reaction mechanism is proposed and the role of ethanol is discussed.
Sarova
G
G
University of Sofia, Department of Chemistry, Bulgaria.
Roussanova
D
D
Jeliazkova
B
B
Yordanov
N D
ND
Malik
M A
MA
O'Brien
P
P
D002219:Carbamates / Q000737:chemistry* / Q000528:radiation effects; D004578:Electron Spin Resonance Spectroscopy; D009942:Organometallic Compounds / Q000737:chemistry* / Q000528:radiation effects; D010084:Oxidation-Reduction; D010777:Photochemistry; D012997:Solvents; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet
D002219:Carbamates; D009942:Organometallic Compounds; D012997:Solvents; C409665:bis(diethyl-diselenocarbamato)copper(II)