Chemical applications of topology and group theory. Part 36. Deltahedral and fused deltahedral organometallic gallium and indium clusters

This paper surveys the structures and chemical bonding in several recently discovered organometallic gallium and indium clusters including the tricapped trigonal prism Ga9(CMe3)9, the bicapped octahedron In8[Si(CMe3)3]6, fused deltahedra such as Ga10[Si(SiMe3)3]6 and In12[Si(CMe3)3]8, and the more complicated supraicosahedral structures [Ga19{C(SiMe3)3}8]2−, Ga22[Si(SiMe3)3]8, and Ga26[Si(SiMe3)3]82−. The Wade–Mingos 2n+2 and Jemmis 2n+2m electron-counting rules appear to be applicable to most of these clusters. The deltahedra found in the supraicosahedral Group 13 metal clusters can be derived from the 12-vertex cuboctahedron and related 13-vertex polyhedra by capping all of the non-triangular faces.