Structural diversity in multinuclear tantalum polyhydrides formed via reductive hydrogenolysis of metal–carbon bonds

Abstract

Using H₂ as a reducing agent, we demonstrate controlled reduction of tri- and tetramethyl tantalum bis(N-heterocyclic carbene)borate complexes to yield low-valent, multinuclear tantalum polyhydrides. Reaction of a Ta(v)Me₃ complex with H₂ afforded a bimetallic, hydride-bridged Ta(IV) complex. The analogous reaction of a Ta(v)Me₄ complex in benzene or toluene yielded bimetallic Ta(III) complexes in which both metals are bound to the same face of a μ-η⁴:η⁴-arene²⁻ ligand.