A new di-mu-alkoxo-bridged dinuclear copper(II) complex of 1-(2-hydroxyethyl)-pyrazole. Synthesis, spectroscopic and magnetic properties and crystal structure
Tanase S, Bouwman E, Driessen WL, Reedijk J, de Gelder R
INORGANICA CHIMICA ACTA 355: 458-461 NOV 20 2003

Abstract:
The crystal structure of [Cu(nhep)Cl](2) (Hnhep = 1-(2-hydroxyethyl)-pyrazole) shows both copper(II) ions to be in a slightly distorted square-planar CuO2NCl environment with the copper(II) ions bridged by the oxygen atoms of the dehydronated ligands. The Cu2O2 core has an asymmetric geometry with a Cu...Cu distance of 3.055 Angstrom. The EPR and magnetic susceptibility measurements indicate the presence of a very strong antiferromagnetic coupling between the copper ions, which results in essential diamagnetic behavior.