Reactions between 1, and the halides GeCl2·dioxane, SnCl2, and PbCl2 gave the isostructural compounds (M = Ge, 2; Sn, 3; or Pb, 4) which contain three-coordinate M. Treatment of the tin derivative 3 with MeI gave the oxidative addition product 5, and this reacted with AgOCOCF3 or AgOSO2C6H4Me-4 to give, respectively, the compounds with X = OCOCF3, 6, or OSO2C6H4Me-4, 7. Despite the presence of the bulky C(SiMe3)2(SiMe2C5H4N-2) ligand, the Sn atom in the solid state structures of 6 and 7 is five-coordinate, and multinuclear NMR studies show that five-coordinate species are present also in THF solutions of 5, 6, and 7.