Notes. Magnetic and spectroscopic properties of dimeric copper(II)N-benzoylvalinates

Abstract

The e.s.r. spectra and temperature-dependent magnetic susceptibility of some complexes of the type [Cu(bzValO)₂], [Cu(bzValO)₂]·H₂O, and [Cu(bzValO)₂L](bzValO =N-benzoylvalinate anion; L = pyridine and 3- or 4-methylpyridine) are reported. Results suggest a dimeric structure for all the complexes with strong antiferromagnetic interactions between the Cu²⁺ ions within the pairs through a superexchange mechanism via the bridging carboxylate groups. A correlation between the values of |2J| for a series of copper (II) amino-acid complexes and monoamine adducts and a comparison with |2J| values of binuclear copper (II) carboxylates are presented.