Syntheses and crystal structures of lithium derivatives of diphosphanes R2P–P(SiMe3)Li · 3L, R = Ph, iPr and iPr2N, L = THF or DME

The reactions of R2P–P(SiMe3)2 (R = Ph, iPr and iPr2N) with BuLi in THF or DME solution lead to ion-contacted lithium derivatives R2P–P(SiMe3)Li · 3THF (R = iPr, iPr2N) with tetrahedrally surrounded Li atoms and to the solvent-separated ionic [Li · 3DME]+[Ph2P–PSiMe3]− with an octahedrally surrounded Li atom as confirmed by X-ray crystal structure analysis. The reaction of BuLi with Ph2P–P(SiMe3)2 is accompanied with a significant side-reaction leading to Ph2P–PPh2 and to LiP(SiMe3)2.

Graphical abstractThe first solvent-separated lithium phosphino-phosphide Ph2P–P(SiMe3)2 + BuLi + 3DME → (Li · 3DME)+(Ph2P–PSiMe3)− + Me3SiBuFigure optionsDownload full-size imageDownload as PowerPoint slide