Persistent phosphinyl radicals from a bulky diphosphine: an example of a molecular jack-in-the-box

The structure of the phosphinyl radical, (P) over dot R-2 [R = CH(SiMe3)(2)], has been determined by gas-phase electron diffraction (GED) together with ab initio molecular orbital calculations, and that of the corresponding diphosphine, (PR2)(2), has been established by X-ray crystallography; the diphosphine behaves as an energy storage reservoir.