Methyl Tin(IV) Derivatives of HOTeF5 and HN(SO2CF3)2:  A Solution Multinuclear NMR Study and the X-ray Crystal Structures of (CH3)2SnCl(OTeF5) and [(CH3)3Sn(H2O)2][N(SO2CF3)2]

The new tin(IV) species (CH3)2SnCl(OTeF5) was prepared via either the solvolysis of (CH3)3SnCl in HOTeF5 or the reaction of (CH3)3SnCl with ClOTeF5. It was characterized by NMR and vibrational spectroscopy, mass spectrometry, and single crystal X-ray diffraction. (CH3)2SnCl(OTeF5) crystallizes in the monoclinic space group P21/n (a = 5.8204(8) Å, b =10.782(1) Å, c =15.493(2) Å, β = 91.958(2)°, V = 971.7(2) Å3, Z = 4). NMR spectroscopy of (CH3)3SnX, prepared from excess Sn(CH3)4 and HX (X = OTeF5 or N(SO2CF3)2), revealed a tetracoordinate tin environment using (CH3)3SnX 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)3SnOTeF5 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)3Sn(OS(CH3)2)2 + cation and the OTeF5 - anion are formed. (CH3)3SnOTeF5 and (CH3)3SnN(SO2CF3)2 react differently with water. While the TeF bonds in the OTeF5 group of (CH3)3SnOTeF5 undergo complete hydrolysis that results in the formation of [(CH3)3Sn(H2O)2]2SiF6, (CH3)3SnN(SO2CF3)2 forms the stable hydrate salt [(CH3)3Sn(H2O)2][N(SO2CF3)2]. This salt crystallizes in the monoclinic space group P21/c (a = 7.3072(1) Å, b =13.4649(2) Å, c =16.821(2) Å, β = 98.705(1)°, V = 1636.00(3) Å3, Z = 4) and was also characterized by NMR and vibrational spectroscopy.