Synthesis and characterization of N-(o-vanillinidene)-p-anisidine and N,N′-bis(o-vanillinidene)ethylenediamine and their metal complexes

Two Schiff bases, N-(o-vanillinidene)-p-anisidine (o-VPAH) and N,N'-bis(o-vanillinidene)ethylenediamine (o-VEDH2), and eleven complexes of the compositions [M(L)(OAc)(H2O)] {where M = Cu(II) (1), Co(II) (2), Mn(II) (3) or Ni(II) (4) and OAcH = CH3COOH}, [Zn(L)(2)].H2O (5), [M(L')(H2O)(2)] {where M = Cu(II) (6) or Ni(H) (7)}, [Zn(L')].2H(2)O (8), [Sm(L')(OAc)(H2O)] (9), [Th(L')(NO3)(2)] (10) and [UO2(L')(H2O)] H2O(11)(where LH = o-VPAH, and L'H-2, = o-VEDH2), were prepared. From the elemental analyses, IR, electronic and NMR spectra, magnetic susceptibility measurements and thermal studies, the mode of chelation of the ligands and geometry of the complex molecules were assigned. In all of the complexes, o-VPAH acts as a monobasic-bidentate ligand and o-VEDH2 acts as a dibasic-tetradentate ligand. The presence of water is revealed by thermograms and supported by the presence of relevant hands in their IR spectra. Suitable structures have been proposed for these complexes.