Rangoli with tin drums: C-H---O bond-assisted supramolecular grids involving organostannoxane clusters

Abstract

The reaction of n-BuSn(O)OH with RCOOH affords hexameric compounds [n-BuSn(O)OC(O)R]₆, R = CH₂C₅H₄FeC₅H₅ (1) and 2,4,6-Me₃C₆H₂ (2). The compounds 1 and 2 have drum-like structures with a prismane type Sn₆O₆ core. Both 1 and 2 form supramolecular 2D grid-like assemblies as a result of intermolecular C-H---O bonds between the ferrocenyl C-H and the carboxylate oxygen in the case of compound 1 and the C-H of the p-CH₃ group and the carboxylate oxygen in the case of compound 2. In each case six stannoxane molecules surround a central hexameric stannoxane in a highly symmetric manner, although C-H---O bonds connect only four molecules together. The overall architecture of the supramolecular assembly is reminiscent of a highly repetitive decorative pattern.