Synthesis and structural studies on polymeric assemblies derived from antimony(III) halide complexes with bi- and tri-dentate and macrocyclic thio- and seleno-ether ligands

Abstract

SbX3 (X = Cl, Br or in some cases I) reacts with one molar equivalent of L [L = MeS(CH2)2SMe, MeS(CH2)3SMe, MeSe(CH2)2SeMe, MeC(CH2SMe)3, MeC(CH2SeMe)3, [12]aneS4 (1,4,7,10-tetrathiacyclododecane), [14]aneS4 (1,4,8,11-tetrathiacyclotetradecane), [16]aneS4 (1,5,9,13-tetrathiacyclohexadecane), [8]aneSe2 (1,5-diselenacyclooctane) or [16]aneSe4 (1,5,9,13-tetraselenacyclohexadecane)] in anhydrous CH2Cl2, MeCN or thf solution to afford colourless to red-orange powdered solids involving a 1 ∶ 1 Sb ∶ L ratio in most cases, and occasionally a 2 ∶ 1 Sb ∶ L ratio. The crystal structures of [SbCl3{MeS(CH2)2SMe}], [(SbBr3)2([14]aneS4)], [SbCl3{MeC(CH2SMe)3}], [SbI3{MeC(CH2SMe)3}] and [SbBr3{MeC(CH2SeMe)3}] all exhibit infinite one- or three-dimensional networks which are assembled from distorted five or six coordinate Sb(III) with primary Sb–X bonding, secondary Sb–S or Sb–Se interactions and retention of the pyramidal SbX3 unit found in the parent halides. The structures of these compounds are discussed in terms of the bonding model used by others for antimony phosphine complexes. They are also compared with the structures of other reported thioether complexes of Sb(III), and with their Bi(III) analogues.