A Zwitterionic Phosphonium Stannate(II) via Hydrogen Splitting by a Sn/P Frustrated Lewis-Pair and Reductive Elimination.

The reactivity of the frustrated Lewis pair (FLP) (F C ) SnCH P(tBu) (1) was investigated with respect to the activation of elemental hydrogen. The reaction of 1 at elevated hydrogen pressure afforded the intramolecular phosphonium stannate(II) (F C ) SnCH PH(tBu) (3). It was characterized by means of multinuclear NMR spectroscopy and single crystal X-ray diffraction. NMR experiments with the two isotopologues H and D showed it to be formed via an H adduct (F C ) HSnCH PH(tBu) (2) and the subsequent formal reductive elimination of pentafluoroethane; this is supported by DFT calculations. Parahydrogen-induced polarization experiments revealed the formation of a second product of the reaction of 1 with H , [HP(tBu) Me][Sn(C F ) ] (4), in H NMR spectra, whereas 2 was not detected due to its transient nature.