A Fluxional Cu8H6 Cluster Supported by Bis(diphenylphosphino)methane and its Facile Reaction with CO2

A copper hydride cluster [Cu-8(m-H)(6)(mu-dppm) (5)](PF6)(2) (dppm= bis(diphenylphosphino) methane) was prepared from reaction of [CuH(PPh3)](6) with dppm in the presence of [Cu(CH3CN)(4)] PF6 and exhibited fluxional behaviors in solution where the hydrides and the phosphines are scrambling around the trans-bicapped octahedral Cu-8 framework. The Cu8H6 complex showed facile reactivity with CO2 (1 atm, RT) to afford a tricopper complex, [Cu-3(m-H)(m-O2CH)(m-dppm)(3)] PF6, which could be developed to unprecedented hydrosilylation of CO2 catalyzed by multinuclear CuH species under mild conditions.