Organothallium compounds: VIII. Arenesulphinatodiorganothallium(III) derivatives

The arenesulphinatodiorganothallium(III) complexes R₂Tl(O₂SR’) (R = Et, Me, Ph, or C₆F₅; throughout R’ = Ph or p-MeC₆H₄) have been prepared by reaction of the appropriate diorganothallium(III) halides and silver arenesulphinates, and gave the complexes Et₂(phen)Tl(O₂SR’), impure Me₂(phen)Tl(O₂SR’), Ph₂(phen or bpy)Tl(O₂SR’), (C₆F₅)₂(phen, bpy, py, or Ph₃PO)Tl(O₂SR’), and (C₆F₅)₂Ph₃AsOTl(O₂SPh) on reaction with the appropriate ligands. Attempts to prepare R₂(bpy)Tl(O₂SPh) (R = Et or Me), (C₆F₅)₂Ph₃AsOTl(O₂S-p-MeC₆H₄), (C₆F₅)₂Ph₃PTl(O₂SPh), and Ph₂(Ph₃AsO)Tl(O₂SPh) failed. The complexes Et₂Tl(O₂SR’) are dimeric with bridging O-sulphinate groups in chloroform, and weak association of the dimeric units is considered to occur in the solid state. Conclusions are more tentative for R₂Tl(O₂SR’) (R = Me, Ph, or C₆F₅) derivatives, since insolubility prevented molecular weight and infrared measurements in solvents of low polarity. However, associated structures with bridging bidentate O-sulphinate groups are likely, and sulphur-oxygen stretching frequencies suggest Me₂Tl(O₂SR’) and Ph₂Tl(O₂SR’) have structures similar to Et₂Tl(O₂SR’). The complexes R₂LTl(O₂SR’) have monomeric structures with O-sulphinate ligands. For L = phen or bpy, the sulphinate groups are either unidentate, giving five-coordinate thallium, or bidentate, giving six-coordinate thallium, and for L = py, Ph₃PO, or Ph₃AsO, unidentate sulphinate groups and four-coordinate thallium are likely.