Controlled Decomposition of an Indium Trihydride Adduct:  Synthesis and Characterization of the First Mixed-Oxidation-State Indium Sub-halide Complex Anion, [In5Br8(quinuclidine)4]

The first example of a compound containing a mixed-oxidation-state indium sub-halide complex anion, [In5Br8(quinuclidine)4]-, has been accessed by the controlled decomposition of an indium trihydride adduct, [InH3(quinuclidine)], in the presence of LiBr. An intermediate in this reaction, [InH2Br(quinuclidine)2], has been isolated and suggests that its mechanism involves hydride−bromide exchange, reductive dehydrogenation, and disproportionation processes.