Telluroether adducts of tin(IV) halides: synthesis, spectroscopy, and structures

The extremely moisture-sensitive [SnX4(Me2Te)(2)] and [SnX4(ditelluroether)] [X = Cl or Br; ditelluroether = C6H4(TeMe)(2)-o, MeTe(CH2)(3)TeMe or PhTe(CH2)(3) TePh] have been prepared from SnX4 and the tellurium compound in anhydrous dichloromethane. The crystal structures of [SnCl4{C6H4(TeMe)(2)-o}] and [SnBr4{C6H4(TeMe)(2)-o}] have been determined; both show distorted-octahedral tin(IV) with the chelating ditelluroether ligand adopting the mesa conformation. Variable-temperature H-1, Te-125-{H-1} and Sn-119-{H-1} NMR studies showed that the complexes undergo rapid ligand exchange in solution. The structures and properties are compared with those of previously described thio-and seleno-ether analogues. Multinuclear NMR spectroscopic studies of mixtures of SiCl4 or GeCl4 and various Group 16 donor ligands in CH2Cl2 solution provided no evidence of adduct formation.