The Girard T reagent and its condensation product with aldehydes - hydrazones have not widely used as ligand in coordination chemistry until few years ago. Recently we have described the monomeric coordination compounds of salicylaldehyde or 2-formylpyridine Girard T hydrazone with iron(III) [1, 2]. In this study we present new copper(II) coordination compounds of the hydrazone formed by condensation of salicylaldehyde with Girard T reagent [H2L]Cl. The formation and composition of the resulting complexes are directly depending of the used copper(II) salts and the nature of the solvent. Two types of complexes have been separated: monomeric and dimeric. In the Fig. 1 the monomeric structure of of chloride salt (a), and dimeric (b) for nitrate derivative. The monomeric units are associated in dimmers via phenoxyl oxygen atom. Fig. 1. ORTEP representation of a monomeric and dimeric structures The magnetic susceptibility versus temperature shows the presence of a strong antiferromagnetic interaction in dimeric units between paramagnetic centers Cu(II) S=1/2. The substituents in the salicylaldehyde moiety influences the Cu- μ ₂O-Cu angle and change the magnitude of the J parameter in magnetic interactions.