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 CuII 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.