EPR evidence for an unexpected symmetric dinuclear species present in the lattice of an asymmetric dinuclear copper complex

The low-temperature single-crystal EPR spectra of [(dien)Cu(ox)Cu(tmen)(H 2O) 2](ClO 4) 2 (I: dien = diethylenetriamine; ox = oxalato; tmen = N,N,N′,N′-tetramethylethylenediamine) revealed that the paramagnetic species that caused the deviation of the magnetic susceptibility from the Bleaney-Bowers equation is a spin triplet containing two equivalent copper ions. The comparison of the magnetic properties of the impurity with those reported in the literature for similar compounds leads us to suggest that [(dien)Cu(ox)Cu(dien)] 2+ species are present in the lattice. © 1986 American Chemical Society.