Structural Diversity in the Solid-State Structures of the Rubidium and Cesium Salts of 2,6-Dimesitylphenylphosphane

A coordination environment reminiscent of a paddle‐wheel is exhibited by aryl groups about one of the two cesium ions in CsP(H)Dmp (Dmp=2,6‐dimesitylphenyl; structure depicted on the right), which has now been synthesized and is found to exhibit Cs+{Cs2[P(H)Dmp]3}− contact ion pairs in the solid state. In contrast, the analogous rubidium compound displays a Rb4P4 cube as the central structural motif.