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

The trinuclear copper(II) complex [Cu-3(cpse)(3)(H2O)(3)].8.5H(2)O has been obtained from mononuclear [Cu(Hcpse)(2)].H2O {H(2)cpse = 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 (H(2)ceph = N-[2-hydroxy-1(S)-methyl-2(R)-phenylethyl] N- methylglycine), prepared from the erythro isomer, was obtained and characterised by X-ray crystallography.