The First Structurally Characterised Example of Silicon in an S6 Coordination Sphere

The reaction of sodium hydro‐tris(phenylthioimidazolyl)borate (NaTmPh) with silicon tetraiodide gives rise to the first crystallographically characterised molecular silicon compounds, [Si(TmPh)2] 2X (X = I– and I3–), in which the silicon is found in a regular S6 environment. The [Si(TmPh)2]2+ cation is subjected to analysis using DFT methods to explain why an S6 coordination motif is preferred to an S4 coordination motif. Reaction of NaTmPh with SiI4 results in an octahedral Silicon complex in an S6 ligand environment. The resulting compound has been characterised crystallographically and been the subject of DFT calculations.