A Stable Terminal Mercury Hydride and Its Reactivity To Form Mercury–Metal Bonds

Organomercury hydrides are typically encountered as unstable intermediates in organic transformations. These compounds are conventionally thought to be intrinsically unstable and have eluded isolation in the condensed phase. Here, we report the synthesis, isolation, characterization, and reactivity of an unexpectedly stable arylmercury hydride using a sterically encumbering fluorenyl-hydrindacene scaffold. The arylmercury hydride readily reacts with metalloradicals and metal hydrides to form bimetallic complexes containing unsupported mercury–metal bonds. These results suggest that the instability of mercury hydride compounds is not due to an intrinsic weakness of the mercury–hydrogen bond, but rather their propensity to undergo bimetallic reactions that result in mercury–mercury bond formation.