Reaction of either LiInH4 or [InH3(NMe3)] with the Arduengo-type carbene :CN(Mes)-C2H2N(Mes), Mes = C6H2Me3-2,4,6, affords the indium trihydride complex [InH3{CN(Mes)-C2H2N(Mes)}]. This compound displays a remarkable thermal stability (dec 115 degreesC). In solution the products of decomposition depend on the solvent used. In toluene decomposition results in liberation of the free carbene and deposition of indium metal, and in tetrahydrofuran in the presence of indium metal hydrogen transfer occurs to give H2CN(Mes)C2H2N-(Mes) and indium metal, while in dichloromethane, chloride abstraction occurs from the solvent to yield [InCl3{CN(Mes)C2H2N(Mes)}]. A number of related compounds have also been prepared and their structures and properties investigated. These include [GaH3{CN-(Mes)C2H2N(Mes)}], which is the most stable gallium trihydride yet reported, and the indium hydride halide complex [InH2Cl{CN(Mes)C2H2N(Mes)}].
