Synthesis of the Bulky Phosphanide [P(SiPr)] and Its Stabilization of Low-Coordinate Group 12 Complexes.

Here, we report an improved synthesis of the bulky phosphanide anion [P(SiPr)] in synthetically useful yields and its complexation to group 12 metals. The ligand is obtained as the sodium salt NaP(SiPr) in a 42% isolated yield and a single step from red phosphorus and sodium. This is a significantly higher-yielding and safer preparation compared to the previously reported synthesis of this ligand, and we have thus applied to the synthesis of the two-coordinate complexes M[P(SiPr)] (M = Zn, Cd, Hg). These group 12 complexes are all monomeric and with nonlinear P-M-P angles in the solid state, with DFT calculations suggesting that this bending is due to the steric demands of the ligand. Multinuclear NMR spectroscopy revealed complex second-order splitting patterns due to strong PP' coupling. This work demonstrates that the synthesis of is viable and provides a springboard for the synthesis of low-coordinate complexes featuring this unusual bulky ligand.