Coordination polymeric chain formed by p -sulfonatocalix[4]arene and organotin. Synthesis and crystal structure

[Sn(Bu)2(H2O)3Sn2(Bu)2(μ-OH)2(H2O)2SC4]·7H2O was obtained by the reaction of p-sulfonatocalix[4]arene and Bu2SnO in 50% alcohol under 60°C. Single-crystal X-ray diffraction analysis indicates that in the complex, there are two kinds of Bu2SnO units. Sn atom in one kind Bu2SnO unit directly combines to the oxygen atom of the sulfonic groups and the Sn atoms in the other unit form a four member Sn2O2 cycle between two Bu2SnO units. Then two sulfonic groups of two p-sulfonatocalix[4]arene combine to the Sn atoms of Sn2O2 forming a 1D polymeric chain. It is found that the molar ratio of p-sulfonatocalix[4]arene to Bu2SnO does not influence the structure of the complex.