The reactivity of the frustrated Lewis pair (FLP) (F5C2)3Sn-CH2-P(tBu)2(1) was investigated with respect to the activation of elemental hydrogen. The reaction of 1 at elevated hydrogen pressure afforded the intramolecular phos-pho-nium stannate(II) (F5C2)2Sn-CH2-PH(tBu)2 (3). It was cha-rac-terised by means of multinuclear NMR spectroscopy, and single crystal X-ray diffraction. NMR experiments with the two isotopologues H2 and D2 showed it to be formed via an H2 adduct (F5C2)3(H)Sn-CH2-PH(tBu)2 (2) and the sub-sequent formal reductive elimination of penta-fluoroethane; this is supported by DFT calculations. Parahydrogen-induced polari-zation experiments revea-led the formation of a second product of the reaction of 1 with H2, [HP(tBu)2Me][Sn(C2F5)3](4), in 1H NMR spectra, whereas 2 was not detected due to its transient nature. © 2020 Wiley-VCH GmbH.