Binuclear and trinuclear nitrato-complexes of copper(II) and nickel(II) with bidentate Schiff bases

The reaction of copper(II) and nickel(II) N-alkylsalicylaldimine complexes with copper(II) and nickel(II) nitrate respectively, results in a series of binuclear copper(II) and trinuclear nickel(II) complexes. The copper complexes exhibit strong pairwise antiferromagnetic interactions and are assigned an approximately planar structure with coordinated nitrato-groups. The nickel complexes show no strong exchange interactions, but they appear to be weakly ferromagnetic. The proposed structure for these complexes contains a central octahedral nickel bonded to two nitrato-groups and two pseudo-tetrahedral nickel atoms. The nitrato-group behaves like a halogen in the copper complexes, but there is no halogen analogue of the nickel complexes.