Magnetic and Spectroscopic Studies on Salicylaldoxime and o-Hydhoxynaphthaldoxime Complexes of Some Divalent 3d Metal Ions

Some novel complexes of salicylaldoxime (H2Salox) and o-hydroxynaphthaldoxime(H2Nolox) having the compositions M(HNolox)2 [M = VO(IV), Mn(II), Fe(II), Co(II), Ni(II) orCu(II)], M(Nolox)2H2O and M(Salox)·2H2O[M = Mn(II), Co(II), Ni(II), Cu(II), or Zn(II)] have been synthesized and their structures investigated by molar conductance, magnetic susceptibility, electronic and infrared spectral measurements. Molar conductivities of 1:2 complexes of H2Nolox indicate their non-electrolytic behaviour, magnetic and electronic spectral studies suggest square pyramidal geometry for VO(HNolox)2, square planar geometry for the other 1:2 complexes and octahedral geometry for 1:1 Co(II), Ni(II) and Cu(II) complexes. The infrared spectral studies show that H2Nolox acts as mononegative bidentate ligand in 1:2 complexes, the bonding sites being nitrogen and phenolate oxygen and as binegative tetradentate ligands in 1:1 complexes bonding through phenolate and iminoximate oxygen bridging in addition to the bonding sites indicated in the 1:2 complexes. Salicylaldoxime exhibits bonding behaviour that is similar to the behaviour exhibited by o-hydroxynaphthaldoxime in its 1:1 complexes.