The bis(thioether)silanes Me 2 Si(CH 2 SR) 2 (abbreviated Bts R , where R ¼ Me or Pr i ), the first two members of a new family of bidentate thioether ligands, have been readily prepared and fully characterized. The tin(IV) tetrahalide derivatives (Bts R )SnX 4 (X ¼ Cl, Br), which comprise the first four metal coordination complexes of these new sulfur-donor ligands, have also been isolated, and the X-ray structure of the tetrabromide derivative (Bts Me )SnBr 4 confirms the chelating nature of the dithioether.