Formation of Tin Macrocycles and Extended Networks

3 Formation of Tin Macrocycles and Extended Networks Application of Inorganic Connectors 

When sulfur replaces oxygen, chelating begins to dominate over bridging, as it occurs in complexes with ligands derived from dithiophosphate derivatives and dithiocarbamates.  

Concerning the oxygen-containing bidentate ligands [R E02+ ] and MC, discrete dimeric, tetrameric and hexameric ring assemblies have been reported for organotin carboxylate, phosphinate, phosphonate monoester, phosphate diester, sulfonate, and tungstate derivatives. 

In these macrocyclic structures, the composition of the central inorganic ring system is [Sn02E] or [Sn02M] , respectively, with n = 2 for the dimer, n = 4 for the tetramer, and n = 6 for the hexamer, thus 

NMR spectroscopic, cryoscopic, and related studies have shown that macrocyclic triorganotin tetramers and hexamers undergo transformations fast on the NMR timescale in solution. 

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