Synthesis, spectral and thermal studies of Bis-2,6-dimethanolpyridine complexes of Co(II), Ni(II), Cu(II) and Zn(II) saccharinates: Crystal structures of [Ni(dmpy)(2)](sac)(2)center dot 2H(2)O and [Zn(dmpy)(2)](sac)(2)center dot 2H(2)O

Abstract

The new transition metal saccharinate complexes of 2,6-dimethanolpyridine (dmpy) have been synthesized and characterized by elemental analyses, magnetic measurements, UV-Vis and IR spectra. Co(II), Ni(IT), Cu(II) and Zn(II) form mononuclear octahedral complexes formulated as [M(dmpy)(2)(sac)(2) . H2O, where sac is the saccharinate anion. The dmpy ligand coordinates to the metal ions as a tridentate N,O,O'-donor ligand through the amine nitrogen and two hydroxyl oxygen atoms, while the sac ion is present as the counter-ion. The crystal structures of the [Ni(dmpy)2](sac)(2) . 2H(2)O and [Zn(dmpy)2](sac)(2) . 2H(2)O Complexes were determined by single X-ray diffraction. The crystals are isostructural with the triclinic crystal system (P (1) over bar) and both the Ni(II) and Zn(II) ions have distorted octahedral coordination by two dmpy ligands in a meridional configuration. Both crystal structures are stabilized by hydrogen bonds and aromatic pi-pi stacking interactions forming a three-dimensional network.