The Structure of Tri(cyclohexyl)tin Chloride between 108 and 298 K: A Compound in Which Molecular Dimensions Vary with Temperature

Care is necessary when relating physical data obtained at one temperature on compounds showing significant
intermolecular interactions to X-ray data obtained at other temperatures. This is revealed by the determination of
the structure of tri(cyclohexyl)tin chloride at nine different temperatures between 108 and 298 K. In the crystal, the
molecules pack in chains parallel to the c axis with the Sn and Cl atoms close to the plane, with y = 0.25. At low
temperature, successive molecules in the chain are related by the glide plane in space group P21/c, and there is
significant intermolecular interaction. As the temperature is raised, the Cy3SnCl···Sn interactions weaken and the
intramolecular Sn−Cl bonds strengthen. At about 248 K, there is an order−disorder transition to space group
P21/m with the c axis halved, and at room temperature the structure is best described as comprising discrete
molecules, as previously reported. Thus, some of the molecular dimensions, in particular the Sn−Cl bond lengths,
are not constant but are functions of temperature.