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 new compounds Ag2ZnIm4 and Ag2CoIm4 (Im = imidazolate) were solved. Heterometallic Co/Zn imidazolates showed the standard ZIF-8 crystal structure while Ag/Zn and Ag/Co systems were isostructural with the copper analogs. The powders were further characterized by EDX, UV-Vis and FTIR ATR spectroscopy in solid state. The catalytic experiments indicated that out of the studied heterometallic compounds only Ag2Co(Im)4, exhibits some catalytic activity in the reaction of oxidation of 1-phenylethanol by tert-butylhydroperoxide at elevated temperature.