Abstract
Single-crystal EPR investigations on the paramagnetic Cu-II impurity present in the binuclear anti ferromagnetically coupled complex (n-Bu4N)(2)[(dmit)Cu-II(tto)Cu-II (dmit)] (dmit = dimercaptoisotrithion, tto tetrathiooxalate) identify the mononuclear S = 1/2 complex [Cu-II(dmit)(2)](2-) as being responsible for the observed EPR spectra. The Cu-63 hyperfine structure data as well as the data obtained from density functional theory (DFT) and extended Huckel theory molecular orbital (EHT-MO) calculations were used to characterize the spin-density distribution of the copper complex.