Charting No-Man's Land in d0 Transition Metal Six-Coordination: Structure Predictions for the Complexes [WCl5CH3], [WCl4(CH3)2], and [WCl3(CH3)3]

Unusual structures between octahedral and trigonal-prismatic are found by density functional calculations for the “simple” six-coordinate d⁰ title complexes. While a distorted octahedron is still slightly lower in energy than a prismatic structure for [WCl₅CH₃], intermediate structures start to appear for [WCl₄(CH₃)₂] (see picture). In the case of [WCl₃(CH₃)₃], prismatic arrangements are already more favorable. These and many related compounds should be accessible experimentally.