The new tin(IV) species (CH3)(2)SnCl(OTeF5) was prepared via either the solvolysis of (CH3)(3)SnCl in HOTeF5 or the reaction of (CH3)(3)SnCl with ClOTeF5. It was characterized by NMR and vibrational spectroscopy, mass spectrometry, and single crystal X-ray diffraction. (CH3)(2)SnCl(OTeF5) crystallizes in the monoclinic space group P2(1)/n (a = 5.8204(8) Angstrom, b =10.782(1) Angstrom, c =15.493(2) Angstrom, beta = 91.958(2)degrees, V = 971.7(2) inverted perpendicular(3), Z= 4). NMR spectroscopy of (CH3)(3)-SnX, prepared from excess Sn(CH3)(4) and HX (X = OTeF5 or N(SO2CF3)(2)), revealed a tetracoordinate tin environment using (CH3)(3)SnX as a neat liquid or in dichloromethane-d(2) (CD2Cl2) solutions. In acetone-d(6) and acetonitrile-d(3) (CD3CN) solutions, the tin atom in (CH3)(3)SnOTeF5 was found to extend its coordination number to five by adding one solvent molecule. In the strong donor solvent DMSO, the Sn-OTeF5 bond is broken and the (CH3)(3)Sn(O= S(CH3)(2))(2)(+) cation and the OTeF5-anion are formed. (CH3)(3)SnOTeF5 and (CH3)(3)SnN(SO2CF3)(2) react differently with water, While the Te-F bonds in the OTeF5 group of (CH3)(3)SnOTeF5 undergo complete hydrolysis that results in the formation of [(CH3)(3)Sn(H2O)(2)](2)SiF6, (CH3)(3)SnN(SO2CF3)(2) forms the stable hydrate salt [(CH3)(3)Sn(H2O)(2)][N(SO2CF3)(2)]. This salt crystallizes in the monoclinic space group P2(1)/c (a = 7.3072(1) Angstrom, b = 13.4649(2) Angstrom, c =16.821(2) Angstrom , beta = 98.705(1)degrees, V = 1636.00(3) Angstrom(3), Z = 4) and was also characterized by NMR and vibrational spectroscopy.