Rangoli with Tin Drums:  C−H- - -O Bond-Assisted Supramolecular Grids Involving Organostannoxane Clusters

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.