Synthesis of Mono-, Bis- and Tris(pentafluoroethyl)tin Derivatives, (C F ) SnX (X=Ph, Me, Cl, Br, Cp; n=1-3).

For (pentafluoroethyl)phenylstannanes, (C F )  SnPh (n=1-3), and dimethylbis(pentafluoroethyl)stannane, (C F ) SnMe , a high yield synthesis was developed by the use of LiC F as a C F transfer reagent. The treatment of these products with gaseous hydrogen chloride or hydrogen bromide afforded (C F ) SnX (X=Cl, Br; n=1-3) in good yields. The (pentafluoroethyl)stannanes were fully characterized by H, C, F and Sn NMR, IR spectroscopy and mass spectrometry. The treatment of the (pentafluoroethyl)tin halides (C F ) SnX with 1,10-phenanthroline (phen) led to the formation of the corresponding octahedrally coordinated complexes [(C F ) SnX (phen)], the structures of which were elucidated by X-ray diffraction analyses. The bromostannane (C F ) SnBr reacted with sodium cyclopentadienide to give the (η -cyclopentadienyl)tris(pentafluoroethyl)stannane, (C F ) SnCp, for which single-crystal X-ray diffraction analysis could be performed. The coupling constants J( Sn, C) and J( Sn, F) of all new stannanes are strongly correlated and sensitive to the substitution pattern at the tin atom. For both coupling constants a negative sign could be assigned.