Charge-transfer photochemistry of the ternary complex (dithio-diseleno-carbamato)copper(II).
Photolysis of the ternary system consisting of diethyldithiocarbamate (Et2dtc), diethyldiselenocarbamate (Et2dsc) and copper(II) (1:1:1) has been studied in isobutylmethylketone (IBMK), toluene, chloromethane and chloromethane/ROH solutions (chloromethane = CCl4, CHCl3 or CH2Cl2 and ROH = EtOH or i-PrOH). The results obtained by EPR techniques and UV-Vis data indicate that a homolytic Cu-S bond cleavage involving the dithiocarbamate (dtc) ligand appears as the primary photo-process in Cu(Et2dtc)(Et2dsc) photolysis. Further conversion of the primary photoproduct Cu(I)(Et2dsc) is discussed in terms of a specific interaction with the solvent. In chloromethanes and chloromethane/ROH Cu(I)(Et2dsc) is oxidised by the solvent to give the corresponding paramagnetic mixed-ligand Cu(II)(Et2dsc)Cl complex and/or its chloride-bridged and EPR silent dimer Cu2(Et2dsc)2Cl2. The formation of the monomeric species occurs through a co-ordination of the alcohol molecule in the xy plane of the complex. Because of its co-ordination inertness, toluene poorly stabilises the primary photoproduct Cu(I)(Et2dsc), thus providing an effective primary recombination process and lower efficiency of Cu(Et2dtc)(Et2dsc) photolysis. The formation of the bis-solvated mixed-ligand complex Cu(II)(Et2dsc)+ in IBMK is also discussed.
Jeliazkova
B G
BG
Department of Chemistry, University of Sofia, Bulgaria.
Dimitrova
A
A
Yordanov
N D
ND
D002219:Carbamates / Q000737:chemistry; D002627:Chemistry, Physical / Q000379:methods; D002713:Chlorine / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D005609:Free Radicals; D007659:Ketones / Q000737:chemistry; D008024:Ligands; D008027:Light; D008697:Methane / Q000737:chemistry; D008737:Methyl Chloride / Q000737:chemistry; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000737:chemistry; D010100:Oxygen / Q000378:metabolism; D013053:Spectrophotometry; D013859:Thiocarbamates / Q000737:chemistry; D014050:Toluene / Q000737:chemistry
D002219:Carbamates; D005609:Free Radicals; D007659:Ketones; D008024:Ligands; D009942:Organometallic Compounds; D013859:Thiocarbamates; C409665:bis(diethyl-diselenocarbamato)copper(II); D014050:Toluene; D002713:Chlorine; D003300:Copper; D008737:Methyl Chloride; D008697:Methane; D010100:Oxygen