A reinvestigation of the structures of organotin sulphates and chromates, including the crystal and molecular structure of bis(trimethyltin) sulphate dihydrate

The structures of a group of triorganotin sulphates and chromates have been studied by ¹¹⁹Sn n.m.r. and Mössbauer spectroscopies. All the compounds (SnR₃)₂EO₄·nH₂O (R = Me, E = Cr, n = 0; R = Me or Buⁿ, E = S, n = 0; R = Me, E = S, n = 2) form polymeric lattices in the solid state, although for (SnBuⁿ₃)₂SO₄ an irregular lattice incorporating both four- and five-co-ordinate tin atoms is postulated. The structure of (SnMe₃)₂SO₄·2H₂O has been determined by an X-ray study. Crystal data: orthorhombic, space group Pbcn, a = 11.245(4), b = 12.695(5), c = 10.811(4) Å, Z = 4. The geometry about tin is trigonal bipyramidal with a trans-O₂SnC₃ stereochemistry about the metal, one of the axial sites being occupied by a molecule of hydration. Hydrogen bonding between oxygens of the anion and the solvate produces a three-dimensional network lattice.