SYNTHESES, STRUCTURE AND MAGNETIC-PROPERTIES OF DINUCLEAR OXAMIDATO-BRIDGED COPPER(II) COMPLEXES

A new N,N'-disubstituted oxamide ligand H4OBO which I represents N,N'- bis(2-hydroxybenzyl)oxamide, related monomeric copper(II) complex salt Na-2[Cu(OBO)] . H2O and two oxamidato-bridged dinuclear copper(II) co mplexes, namely [Cu-2(OBO) (bipy)] . 2H(2)O (1), [Cu-2(OBO)(py)(4)] (2 ) (bipy = 2,2'-bipyridine, py = pyridine) have been synthesized. Singl e crystal X-ray analysis revealed that the complex 2 has a trans-oxami dato-bridged dinuclear copper(II) structure, in which each copper(II) ion exhibits a distorted square pyramidal surrounding. Complex 2 is ra pidly turned into a complex [Cu-2(OBO)(py)(3)(H2O)(2)] (3) when expose d to the air. Based on the spin Hamiltonian H = -2JS(A) . S-B, the mag netic susceptibility data of 1 and 3 have been best fitted with J valu es of 209 and 161 cm(-1), respectively.