Seven-co-ordination in µ-oxalato-bis[(di-n-propyl sulphoxide)nitratodiphenyltin(IV)]: spectroscopic properties and X-ray crystal structure

Abstract

The title compound has been synthesised and its spectroscopic properties and X-ray structure have been studied. The structure was refined by least-squares techniques to R 4·5% for 3083 independent reflections. Crystals are triclinic, space group P, with unit-cell dimensions: a= 13·334(7), b= 11·860(6), c= 9·424(6)Å, α= 51·3(2), β= 77·5(2), γ= 71·7(2)°, Z= 1, (C₁₉H₂₄NO₆SSn)₂. The co-ordination around tin(IV) is pentagonal bipyramidal, the nitrate and oxalate anions and the sulphoxide molecule being equatorial, with the two phenyl rings at the apices. The oxalate ion acts as a centrosymmetric bridge between two co-ordination polyhedra. Some disorder occurs in the sulphoxide molecule, which occupies two positions around the O–Sn bond.