Solvothermal synthesis, structure and catalytic activity of a mixed-valence CuI/CuII complex with 1-D chain structure

A complex of composition [CuI4CuII(mtpo)4(H2O)2Cl2]n (1) was synthesized from reaction of Hmtpo (Hmtpo = 5-methyl-[l,2,4]-triazolo-[l,5-a]-pyrimidin-7-o1) with one equivalent of CuCl2·2H2O in water at 100 °C under autogenous pressure. Complex 1 was fully characterized by X-ray single crystal diffraction, elemental analysis and IR spectroscopy. X-ray analysis reveals that complex 1 is a mixed-valence coordination polymer and displays 1-D chain structure. Compound 1 was able to heterogeneously catalyze the ketalization reaction of 2-butanone and ethylene glycol to afford 2-ethyl-2-methyl-[1,3]-dioxolane in excellent yield under mild conditions.