Synthesis and Characterization of the Dinuclear Polyhydrides [Os2H7(PPh i Pr2)4]+ and [Os2H6(PPh i Pr2)4]

The dinuclear osmium polyhydride [Os2H7(PPh i Pr2)4][HC(SO2CF3)2] (1) was synthesized by the protonation of [OsH6(PPh i Pr2)2] with bis(trifluoromethylsulfonyl)methane. Treatment with amine bases was not able to deprotonate 1, but reaction with potassium hydride gave the corresponding neutral polyhydride [Os2H6(PPh i Pr2)4] (2). Single crystal X-ray diffraction revealed that 1 and 2 both crystallize in the P21/c space group and are classical polyhydrides containing similar Os(μ-H)3Os cores with Os−Os distances of 2.5431(1) Å and 2.5448(2) Å, respectively. These structures represent rare examples of dinuclear osmium polyhydrides with six or more hydride ligands.