Synthesis, crystal structure and magnetic properties of the triangulo-tricopper(ii) complex [Cu3(cpse)3(H2O)3]·8.5H2O

Abstract

The trinuclear copper(II) complex [Cu₃(cpse)₃(H₂O)₃]·8.5H₂O has been obtained from mononuclear [Cu(Hcpse)₂]·H₂O {H₂cpse = N-[2-hydroxy-1(S)-methyl-2(S)-phenylethyl]-N-methylglycine, threo isomer} and crystallographically characterised. The structure of the compound consists of three Cu^II atoms, each having distorted square-pyramidal geometry, linked by oxo-bridges to form an equilateral triangular array. The magnetic behaviour corresponds to an antiferromagnetically coupled triangular system, with J = −114.2 cm⁻¹. The EPR spectra at different temperatures have been determined. The analogue [Cu(Hceph)₂]·H₂O (H₂ceph = N-[2-hydroxy-1(S)-methyl-2(R)-phenylethyl]-N-methylglycine), prepared from the erythro isomer, was obtained and characterised by X-ray crystallography.