CRYSTAL-STRUCTURE AND SPECTRA OF A COMPLEX RESULTING FROM COPPER(II) NITRATE WITH THE BIS SCHIFF-BASE OF THIOPHENE-2-ALDEHYDE AND DIETHYLENE TRIAMINE

The crystal structure of thylene)amino]-ethyl]-1,2-ethanediamine-coppe r(II) hydrate, C14H17N5 . O6S2Cu . H2O, has been determined by single crystal X-ray diffraction technique. It crystallizes in the orthorhomb ic system, space group Pbca, with a = 6.7511(6) angstrom, b = 20.3188( 16) angstrom, c = 29.053(3) angstrom, V = 3985 angstrom3 and Z = 8. Th e structure was solved by direct phase determination and refined by le ast-squares to a final R = 0.039 (R(w) = 0.038) for 1664 observed uniq ue reflections [F(o) > 5sigma(F(o))]. The copper atom is bonded to the three nitrogen atoms of the organic ligand [1.981(5) angstrom, 1.986( 5) angstrom, 1.996(4) angstrom] and to an oxygen atom of each of the t wo nitrate groups [1.992(4) angstrom, 2.294(4) angstrom] in a distorte d square pyramidal arrangement. Additionally, there is a very weak Cu- O bond [2.655 angstrom] with one of the nitrate groups. The water mole cule, as well as both nitrate groups, participate in hydrogen bond for mation. The IR and electronic spectra are in accordance with the estab lished features of the structure. The molar conductivity indicates tha t the complex is a 1:1 electrolyte, while the magnetic moment is consi stent with monomeric copper(II) units.