CHARACTERIZATION OF THE TIN(II) HYDROXIDE CATION [SN-3(OH)(4)](2-STRUCTURE OF TRITIN(II) TETRAHYDROXIDE DINITRATE() AND THE CRYSTAL)

The crystal structure of Sn-3(OH)(4)(NO3)(2) has been determined using single-crystal X-ray diffraction and refined by full-matrix least-squ ares analysis to R(1) = 0.0323 and wR(2) = 0.1203. The complex crystal lises in the monoclinic space group P2(1)/n, with a = 7.729(1), b = 9. 086(3), c = 14.159(3) Angstrom. beta = 90.65(2)degrees and Z = 4. The tin(II) atoms are contained in discrete polynuclear [Sn-3(OH)(4)](2+) cluster units in which each tin is bonded pyramidally to three short n earest-neighbour cluster hydroxide oxygen atoms. A distorted octahedro n of oxygen atoms around the tin(II) atoms is completed by three longe r contacts to nitrate oxygens in the directions in which the tin non-b onding electron pairs point. One of the OH groups in [Sn-3(OH)(4)](2+) is unique in that it is bonded to all three cluster tin atoms. This c ation is considered to be one of the main products of the hydrolysis o f tin(II) in aqueous solution. Raman spectroscopic data for Sn-3(OH)(4 )(NO3)(2) have also been obtained and the known Mossbauer data are dis cussed with reference to the structure.