A Neutral Geminal Tin/Phosphorus Frustrated Lewis Pair.

The geminal frustrated Lewis pair (FLP) (F5 C2 )3 SnCH2 P(tBu)2 (2) was prepared by reacting (F5 C2 )3 SnCl with LiCH2 P(tBu)2 . 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 (CO2 , SO2 , CS2 , PhNCO, HCl, (Ph3 P)AuCl). However, it shows no reaction in H/D scrambling experiments with H2 /D2 mixtures and binds CO2 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.