CRYSTAL-STRUCTURE AND SPECTRA OF THE MIXED-LIGANDS COMPLEX 1-(2-THENOYL)-2-[1'(2''-PYRIDYL)-ETHYLIDENE]HYDRAZINO-ACETATO LEAD(II)

The crystal structure of the title compound, (C14H13N3O3PbS)2, has been determined from three-dimensional X-ray diffraction data. The crystals are monoclinic, space group P2(1)/c with a = 10. 523 (1) angstrom, b = 8.9922(4) angstrom, c = 16.6720(7) angstrom, beta = 104.142(4)-degrees and Z = 2. The structure was solved by the heavy-atom method and refined by least-squares to a final R = 0.040 (R(w) = 0.031) for 2393 observed unique reflections [F(o) > 5sigma(F(o))]. The lead atom is bonded to the 1-(2-thenoyl)-2-[1'(2''-pyridyl)ethylidene]hydrazine ligand through the carbonyl oxygen, the pyridinyl nitrogen and the azomethinic nitrogen [Pb-O(thenoyl) 2.341(4) angstrom, Pb-N(azomethine) 2.410(6) angstrom, Pb-N(pyridine) 2.566(6) angstrom]. The lead atom is further chelated by the acetate ligand [Pb-O(2)2.290(6) angstrom, Pb-O(3) 2.868(6) angstrom], while an additional weak interaction occurs between this atom and an acetate oxygen of another molecule [Pb-O(3)i 3.002(6) angstrom]. In this way dimer units are for-med, the coordination geometry of the lead atom being that of a distorted pentagonal pyramid. The dimensions of the two organic ligands are as expected. The IR and electronic spectra are in accordance with the established structure from X-ray data. Conductivity measurements indicate the non-electrolytic character of the complex.