Template synthesis and X-ray structure determination of unsymmetrical tetradentate Schiff base complexes of nickel(II) and copper(II)

Nickel(II) and copper(H) complexes of unsymmetrical tetradentate Schiff bases have been synthesized by the template reaction of the half-units N-(1-hydroxy-2-acetonaphthone)-1-amino-2-phenyleneimine) (HL) and N-(2-hydroxyacetophenone)-1-amino-2-phenyleneimine (HL1) with glyoxal monophenylhydrazone (HL2). The ligands (L-L-2) and (L-1-L-2) are formed in situ, respectively. The complexes have been characterized by molar conductance, IR, H-1 NMR and UV spectroscopy. The crystal structure of the Ni(II) complexes have been determined by X-ray crystallography and exhibit square-planar conformation. Crystals of Ni(L-1-L-2) are monoclinic, space group P2(1), with a = 10.2552(5), b=7.3422(4), c= 12.2414(6)Angstrom, beta =93.0910(10)degrees, Z=2. Crystals of Ni(L-L-2) are monoclinic, space group C2/c, with a=24.5353(4), b=9.8615(3), c=22.2809(5)Angstrom, beta =122.7710(10)degrees, Z=8. The Ni-O and Ni-N bonds have very similar lengths and form a regular square-planar structure.