Synthesis and characterization of high nuclearity bimetallic group 8-group 10 transition metal cluster complexes.

摘要

In past years bimetallic nanoparticle catalysts have been shown to exhibit superior catalytic properties, due to the presence of different metals such that one metal performs a certain role in a catalytic cycle and the other performs another function. Our goal was to synthesize bimetallic cluster complexes containing cheap metals for the application in heterogeneous catalysis. We have reported the reaction of Fe5(C)(CO)15with Ni(COD) 2, in acetonitrile solvent to afford the nickel-iron complex Fe 5(C)Ni(NCMe)(CO)15. In addition, some chemistry with this compound was studied which gave new Fe-Ni carbide clusters with varying Fe-Ni ratios. Similar chemistry was observed with the reaction of Ru5(C)(CO) 15 with Ni(COD)2. Electronic unsaturation in transition metal complexes is induced by bulky ligands. The bulky ligands shield the metal center from the approach of large molecules, leaving enough room for the selective approach of small molecules. Bulky ligands such as phosphines, stananes, germanes and N-heterocyclic carbenes stabilize the reactive intermediates of transition metal complexes. Based on this approach, we have synthesized Ru-Ge cluster complexes from the reaction of bulky tertiary butyl germane, ButGeH 3 with ruthenium carbonyl complexes. We have also synthesized Ru-Pt bimetallic transition metal cluster complexes with bulky N-heterocyclic carbene ligand. All the new compounds were structurally characterized by single-crystal X-ray diffraction analyses.