Bis(3-methyl-2-pyridyl)ditelluride and pyridyl tellurolate complexes of zinc, cadmium, mercury: Synthesis, characterization and their conversion to metal telluridenanoparticles

Abstract

Treatment of an acetonitrile solution of metal chloride with bis(3-methyl-2-pyridyl)ditelluride, [Te₂(pyMe)₂], in the same solvent yielded complexes of composition [MCl₂{Te₂(pyMe)₂}] (M = Zn or Cd) whereas reactions of [MCl₂(tmeda)] with NaTepyR (R = H or Me) gave tellurolate complexes of the general formula [M(TepyR)₂] (M = Cd or Hg). When the cadmium complex [Cd(Tepy)₂] was crystallized in the presence of excess tmeda, [Cd(Tepy)₂(tmeda)] was formed exclusively. These complexes were characterized by elemental analyses, uv-vis, ¹H NMR data. The crystal structures of [ZnCl₂{Te₂(pyMe)₂}] and [Cd(Tepy)₂(tmeda)] were established by single crystal X-ray diffraction. In the former zinc is coordinated to nitrogen atoms of the pyridyl group, while in the latter the coordination environment around tetrahedral cadmium is defined by the two neutral nitrogen atoms of tmeda, and two pyridyl tellurolate ligands. Thermal behavior of some of these complexes was studied by thermogravimetric analysis. Pyrolysis of [M(Tepy)₂] in a furnace or in coordinating solvents such as hexadecylamine/tri-n-octylphosphine oxide (HDA/TOPO) at 350 and 160 °C, respectively gave MTe nanoparticles, which were characterized by uv-vis, photoluminiscence, XRD, EDAX and TEM.