Synthesis of group IV (Zr, Hf)-group VIII (Fe, Ru) heterobimetallic complexes bearing metallocenyl diphosphine moieties and their application to catalytic dehydrogenation of amine-boranes

摘要

A series of heterobimetallic complexes, including [M~1Me(μ- η~5:η~1-C_5H_4PEt _2)_2M~2Cp*] (5a, M~1 = Zr, M ~2 = Ru; 5b, M~1 = Hf, M~2 = Ru; 5c, M~1 = Zr, M~2 = Fe) have been prepared and characterized by X-ray analyses. Dehydrogenation of Me_2NH?BH_3 takes place in the presence of a catalytic amount of these heterobimetallic complexes. Studies on the reaction pathway of the catalytic dehydrogenation of Me _2NH?BH_3 lead us to propose a catalytic cycle where two metal centers cooperatively participate in the catalysis. Here, heterobimetallic hydride species serve as key reaction intermediates.