A Neutral Geminal Tin/Phosphorus Frustrated Lewis Pair.

The geminal frustrated Lewis pair (FLP) (F C ) SnCH P(tBu) (2) was prepared by reacting (F C ) SnCl with LiCH P(tBu) . It is neutral and contains an extremely electronegatively substituted, but relatively soft (hard-soft acid-base, HSAB) acidic tin function. Its FLP-type reactivity was proven by reaction with a variety of small molecules (CO , SO , CS , PhNCO, HCl, (Ph P)AuCl). However, it shows no reaction in H/D scrambling experiments with H /D mixtures and binds CO reversibly, as was observed by VT-NMR spectroscopy. Compound 2 and all its adducts were completely characterized by means of multinuclear NMR spectroscopy, elemental analysis, and X-ray diffraction experiments.