Magnetism of novel Schiff-base copper(II) complexes derived from aminoacids

Magnetic properties of five copper(II) complexes of the formula [CuL3(H2O)2] or [CuL4(H2O)] were investigated. These contain a Schiff-base L derived from salicylaldehyde and aminoacids. The ligand L is represented by four bonding isomers (1 through 4) and it is either tridentate (L3) or tetradentate (L4). The fifth ligand contains sulfonato group instead of the carboxyl one. Structurally, two complexes are monomers (1 and 4), one is a dimer (5), and two are polymers (2 and 3). Their magnetic behaviour is more complex: 1 behaves as an antiferromagnetic Heisenberg diad, 2 and 4 are ferromagnetic chains, 3 is a combined ferromagnetic/antiferromagnetic ladder (ribbon), and 5 exhibits a complex 3D-ordering with unusual temperature evolution of the effective magnetic moment.

Mononuclear and dinuclear Cu(II) complexes with Schiff base ligands possesing the {CuNO3} have been studied by means of magnetic susceptibility and magnetization. The magnetic data of these complexes confirm a considerable variability of magnetic behaviour depending on their structure.Figure optionsDownload as PowerPoint slide