Sn-9(4-) reacts with Pt(PPh3)(4) in ethylenediamine/toluene solvent mixtures in the presence of 2,2,2-cryptand to give four different complexes: "Rudolph's complex" of proposed formula [Sn9Pt(PPh3)(x)](4-) (2), the previously reported [Pt@Sn9Pt(PPh3)](2-) ion (3), and the title complexes Pt-2@Sn-17(4-) (4) and Pt@Sn9H3- (5). The use of Pt(norbornene)(3) instead of Pt(PPh3)(4) gives complex 4 exclusively. The structure of 4 contains two Pt atoms centered in a capsule-shaped Sn-17 cage. The complex is highly dynamic in solution showing single, mutually coupled Sn-119 and Pt-195 NMR resonances indicative of an intramolecular liquidlike dynamic exchange process. Complex 5 has been characterized by selectively decoupled H-1, Sn-119, and Pt-195 NMR experiments and shows similar liquidlike fluxionality. In addition, the H atom scrambles across the cage showing small couplings to both Sn and Pt atoms. Neither 3 nor 4 obeys Wades rules; they adopt structures more akin to the subunits in alloys such as PtSn4. The structural and chemical relevance to supported PtSn4 heterogeneous catalysts is discussed.