Synthesis and structural characterization of a carboxylate bridged tetranuclear copper complex derived from reduced Schiff base asymmetric compartmental ligand containing an amino acid side arm

The dinucleating asymmetric reduced Schiff base compartmental ligand H2L {2-[5-bromo-2-hydroxy-3-(4-methyl-piperazin-1-ylmethyl)-benzylamino]-propionic acid} (see for H2L) gives the tetracopper(II) complex [Cu4L2(CH3COO)4] · 2CH3CN · 2H2O (1) on reaction with (CH3COO)2Cu · H2O. The single crystal X-ray structure of 1 reveals that this complex is a carboxylate bridged dimer of dinuclear copper(II) subunits, in which the copper(II) centers adopt different geometries, resulting in a {Cu4} complex.