The preparation and magnetic and spectral properties of some antiferromagnetic thioether complexes of titanium(III)

Abstract

The reactions of titanium(III) chloride, bromide, and iodide with dimethyl sulphide and tetrahydrothiophen yield the 1:2 adducts TiX₃,2L which are in all cases soluble in the parent thioether but virtually insoluble in all other solvents. The dimethyl sulphide complexes are thermally unstable above room temperature. The complexes TiCl₃,2L are strongly antiferromagnetic with Neél tempertures of ∼320°K, whereas the bromide and iodide complexes appear to have more normal magnetic behaviour over the range 320–80°K, although weak magnetic exchange cannot be ruled out. From magnetic and far-infrared spectral data it is concluded that the chloride complexes are probably dimers with a direct metal–metal bond whereas the bromide and iodide analogues are more likely to be halogen-bridged dimers in the solid state and to contain six-co-ordinate titanium(III).