Supramolecular Sn⋯Cl associations in diorganotin dichlorides and their influence on molecular geometry as studied by ab initio molecular orbital calculations

A number of supramolecular architectures based on hypervalent Sn⋯Cl interactions are observed in a series of eight R₂SnCl₂ structures ranging from tetrameric assemblies to a variety of polymeric motifs. The absence of Sn⋯Cl interactions in the crystal lattice of tBu₂SnCl₂ may be attributed to the bulky size of the tin-bound t-butyl groups that precludes such interactions. The influence of the supramolecular aggregation upon molecular geometry has been investigated using ab initio molecular orbital calculations. These show that invariably more symmetric structures are observed in the absence of hypervalent Sn⋯Cl interactions.