Solvent-Controlled Ring Size in Double C,N-Chelated Stannoxanes

The stannylene (LCN)2Sn where LCN is a chelating ligand (2-(N,N-dimethylaminomethyl)phenyl−) was oxidized by an excess of oxygen, nitrous oxide, or TEMPO free radical, giving dimeric stannoxane [(LCN)2Sn]2(μ-O)2 in dynamic equilibrium with its monomeric form in solution. In the solid state, an unusual tetraoxatetrastannacycle cyclo-[(LCN)2SnO]4 can be crystallized from diethyl ether and the trioxatristannacyclic complex of formula cyclo-[(LCN)2SnO]3 from the hexane solution. The same result has been obtained when C,N-chelated organotin(IV) dihalides ((LCN)2SnX2, where X = Cl or Br) were hydrolyzed with an excess of sodium hydroxide and than dehydrated by azeotropic distillation. The oxo-bridged dihydroxide [(LCN)2Sn(OH)]2(μ-O) has been isolated during the course of this hydrolysis.