Syntheses, characterizations and structures of NO donor Schiff base ligands and nickel(II) and copper(II) complexes

New Schiff base derivatives (L1 and L2) were prepared by the condensation of 2-hydroxy-3-methoxybenzaldehyde (o-vanillin) and 3-hydroxy-4-methoxybenzaldehyde (iso-vanillin) with 5-methylfurfurylamine. Two new complexes [Ni(L1)2] and [Cu(L1)2] have been synthesized with bidentate NO donor Schiff base ligand (L1). The Ni(II) and Cu(II) atoms in each complex are four coordinated in a square planar geometry. Schiff bases (L1 and L2) and complexes [Ni(L1)2] and [Cu(L1)2] were characterized by elemental analyses, FT-IR, UV–vis, mass and 1H, 13C NMR spectroscopies. The crystal structures of the ligand (L2) and complexes [Ni(L1)2] and [Cu(L1)2] have also been determined by using X-ray crystallographic technique.

► o-Vanillin and iso-vanillin with 5-methylfurfurylamine Schiff bases were prepared.
► Ni(II) and Cu(II) complexes of o-vanillin with 5-methylfurfurylamine Schiff base were obtained.
► The Ni(II) and Cu(II) atoms in each complex are four coordinated in a square planar geometry.