Thioxan and selenoxan complexes of metal halides

Abstract

Complexes of various metal halides with thioxan and selenoxan have been prepared and characterised; compounds prepared included BF₃,C₄H₈OS, BCl₃,C₄H₈OS, AlCl₃,C₄H₈OS, AlCl₃,C₄H₈OSe, AlBr₃,C₄H₈OS, SnX₄,2C₄H₈OS and SnX₄,2C₄H₈OSe (X = Cl and Br), TiCl₄,2C₄H₈OSe, TiCl₄,C₄H₈OSe, and NbCl₅,C₄H₈OSe. Compounds of silicon (IV) and germanium (IV) halides, or tin(IV) iodide could not be obtained. Infrared and proton resonance spectra measurements have been made on these and analogous reported compounds to establish the mode of co-ordination. In all cases except BF₃,C₄H₈OS (and possibly BCl₃,C₄H₈OS) co-ordination is through sulphur or selenium rather than oxygen. The significance of the results in relation to current views on A and B (hard and soft) acceptors is discussed.