Synthesis, crystal structures and spectroscopic properties of two Zn(II) Schiff's base complexes of pyridoxal

Two mononuclear zinc(II) complexes, [(ZnLH2Cl)-H-1]Cl center dot 2H(2)O (1 center dot Cl center dot 2H(2)O) and [(ZnLHCl)-H-2]center dot H2O (2 center dot H2O) ((LH2)-H-1 and (LH2)-H-2 are N,N'-bis(pyridoxylidene)ethylenediamine and N,N'-bis(pyridoxylidene)1,3-propanediamine, respectively) have been synthesized and characterized by elemental analysis, FT-IR, fluorescence spectroscopy, TG-DTA and single crystal X-ray diffraction studies. The Zn(II) ion in complex 1 have a square pyramidal geometry with appreciable distortion towards trigonal bipyramid, whereas in 2 it has a geometry which is near the midpoint of square pyramid and trigonal bipyramid. The zinc atom is coordinated by two imine nitrogens, two phenolic oxygens and one chloride ion. The Zn(II) complexes show emission at 462 nm when excited at their lowest energy absorption at 372 nm. (C) 2009 Elsevier Ltd. All rights reserved.