Synthesis, Characterization, and Reactivity of Group 12 Metal Thiocarboxylates, M(SOCR)(2)Lut(2) [M = Cd, Zn; R =...

A series of group 12 metal thiocarboxylate species, M(SOCR)(2)Lut(2) [M = Cd, Zn; R = CH(3), C(CH(3))(3); Lut = 3,5-dimethylpyridine (lutidine)], were synthesized to investigate their potential to act as precursors for the formation of metal sulfide materials. These species were expected to undergo thiocarboxylic anhydride elimination to give stoichiometric metal sulfides and remove the organic supporting ligands cleanly. These species were characterized by (1)H, (13)C, and (where appropriate) (113)Cd NMR spectroscopies, TGA, elemental analysis, and single-crystal X-ray diffraction. The spectroscopic and analytical data were consistent with the formulas identified above, and in the solid state the compounds are monomeric with approximate tetrahedral metal coordination environments and monodentate S-bond thiocarboxylate ligands. Crystal data for Cd(SOCCH(3))(2)Lut(2): crystallized in the triclinic space group P&onemacr;, with a = 8.267(1) Å, b = 9.467(1) Å, c = 14.087(1) Å, alpha = 94.04(1) degrees, beta = 91.49(1) degrees, gamma = 104.03(1) degrees, and Z = 2. Thermal decomposition of these compounds in the solid state or in solution resulted in formation of the corresponding metal sulfide at low temperatures, as seen by powder X-ray diffraction. Evidence for thiocarboxylic anhydride elimination was documented by NMR in solution phase reactions. The effects on thiocarboxylic anhydride elimination, resulting from varying M, R, or solvent media, were examined by heating NMR tube solutions of M(SOCR)(2)Lut(2) in pyridine or toluene. Heating toluene or pyridine solutions of Cd(SOCCH(3))(2)Lut(2) resulted in formation of nanocrystalline, sphalerite CdS, as determined by X-ray diffraction and TEM. These preliminary reactivity studies have revealed the great potential of this highly tailorable chemical system as precursors to group 12 metal sulfido species.