(1,2-Dicarba-closo-dodeca-boran-yl)trimethyl-methanaminium iodide.

The title compound, 1-(CH(3))(3)NCH(2)-1,2-C(2)B(10)H(11)·I(-) or C(6)H(22)B(10)N(+)·I(-), was obtained by the reaction of (1,2-dicarba-closo-dodeca-boran-yl)dimethyl-methanamine with methyl iodide. The asymmetric unit contains two iodide anions and two (o-carboran-yl)tetra-methyl-ammonium cations. The bond lengths and angles in the carborane cage are within normal ranges, but the N-C(methyl-ene)-C(cage) angle is very large [120.2 (2)°] because of repulsion between the carborane and tetra-methyl-ammonium units. In the crystal, ions are linked through C-H⋯I hydrogen bonds.