New heterometallic Co/Zn, Ag/Co, and Ag/Zn imidazolates: structural characterization and catalytic activity in the oxidation of organic compounds.

Nanocrystalline powders of monometallic and bimetallic imidazolates of Co, Zn and Ag were produced by a reaction carried out in water. The powders were characterized by powder X-ray diffraction and the crystal structures of the new compounds Ag 2 ZnIm 4 and Ag 2 CoIm 4 (Im = imidazolate) were solved. Heterometallic Co/Zn imidazolates showed the known Zn- zni crystal structure while Ag/Zn and Ag/Co systems were isostructural to the copper analogs. The powders were further characterized by EDX, UV-Vis and FTIR ATR spectroscopy in the solid state. The catalytic experiments indicated that out of the studied heterometallic compounds only Ag 2 Co(Im) 4 exhibits some catalytic activity in the oxidation reaction of 1-phenylethanol with tert -butylhydroperoxide at elevated temperatures.