ESR and Optical Absorption Studies in Copper Diethyldithiocarbamate

Abstract

ESR investigations at X band and optical-absorption measurements have been reported in single crystals of copper (II) diethyldithiocarbamate Cu[S2CN(C2H5)2]2 diluted to 0.2% with the corresponding zinc complex. The measurements have been made both at room and liquid-oxygen temperatures. ESR measurements gave the following values for the parameters in spin Hamiltonian g‖ = 2.1085, g⊥ = 2.023(6), A63 = 142.4×10−4 cm−1, A65 = 152.0×10−4 cm−1, B = 22.4×10−4 cm−1, Q′∼3×10−4 cm−1. Polarized optical absorption study has made possible a proper assignment of the absorption bands to their corresponding transitions. This has led to information regarding the ordering of the MO levels of the complex. The coefficients used in the MO description of the complex have been calculated from the observed parameters. The results show that the metal ligand B1g σ bond is purely covalent and that the out-of-plane π bonding is appreciably covalent whereas the in-plane π bonding is ionic. Further, it is noted that the metal ligand binding is more covalent with sulfur as ligand than with oxygen or nitrogen.