Two novel zinc(II) complexes of N '-[1-(2-pyridyl)ethylidene]morpholine-4-carbothiohydrazide

Two novel zinc(II) complexes of a morpholine derivative of 2-acetylpyridine N-4-substituted thiosemicarbazone, i.e. N'-[1-(2-pyridyl)ethylidene]morpho line-4-carbothiohydrazide (HL), have been studied. in the acetato-zinc(II) complex, catena-poly[[{N'-[1-(2-pyridyl-kappa N)ethylidene]morpholine-4-car bothiohydrazide-kappa(2)N',S} zinc(II)]-mu-(acetato-kappa(2)O:O')], [Zn(C12 H15N4OS)(C2H3O2)], a deprotonated L ligand coordinates to the Zn-II atom th rough its three donor atoms (N, N' and S), and the two O atoms of the aceta to group bridge two Zn-II atoms in a twofold screw axis along b to form a l inear polymer, carena-poly[Zn-II(L)-mu-(OAc-O,O')](n). The acetato group co nnects the Zn-II atoms in an anti-syn arrangement. In the nitrate complex, bis(nitrato-kappa O){N'-[1-(2-pyridyl-kappa N)ethylidene]morpholine-4-carbo thiohydrazide-kappa(2)-N',S}zinc(II), [Zn(NO3)(2)(C12H16N4OS)], a neutral H L and two NO3- ligands coordinate to the Zn-II atom and the complex is mono meric. In both complexes, the coordination geometry around the five-coordin ate Zn-II atom is described as an intermediate between regular square pyram idal and trigonal bipyramidal, due to the planar tridentate thiosemicarbazo ne ligand.