Making the unconventional μ2-P bridging binding mode more conventional in phosphinine complexes

摘要

Phosphinines, as aromatic heterocycles, usually engage in coordination as η ~(1) -P σ-complexes or η ~(6) -phosphinine π-complexes. The μ ~(2) -P bridging coordination mode is rarely observed. With the aim to study the effect of different electronic configurations of phosphinines on the coordination modes, a series of anionic phosphinin-2-olates and neutral phosphinin-2-ols were prepared with moderate to high yield. Then the coordination chemistry of these two series was studied in detail towards coinage metals (Au( I ) and Cu( I )). It is observed that the anionic phosphinin-2-olates possess a higher tendency to take a bridging position between two metal centers compared to the neutral phosphinin-2-ols. Based on these experimental findings bolstered by DFT calculations, some insight is gained on how the unconventional μ ~(2) -P phosphinine bridging coordination mode can be made more conventional and used for the synthesis of polynuclear complexes.