Structure of 2,2-dibutyl-1,3,2-dioxastannolane in the solid state

Abstract

The structure of 2,2-dibutyl-1,3,2-dioxastannolane has been determined by single-crystal X-ray diffraction. Dioxastannolane units are associated into an infinite ribbon polymer, in which the tin is surrounded by two carbon atoms and four oxygen atoms in a highly distorted octahedral arrangement. Within each unit the average Sn–O bond length is 2.04(1)Å, and between each unit it is 2.51(1)Å. The endocyclic O–Sn–O angle is 79.0(5)°, and the exocyclic C–Sn–C angle is 138.6(6)°. The Mössbauer spectra of this compound and of related glucose and mannose derivatives are reconciled with their structures. In the mannose derivative, overlapping signals can be distinguished for the five- and six-co-ordinate tin atoms in the ratio of 3 : 2. In solution and in the solid state, the ¹¹⁹Sn n.m.r. spectrum of 2,2-dibutyl-1,3,2-dioxastannolane shows δ–189 and –230 respectively, indicative of the change from five- to six-co-ordination.