Donor properties of sulphides—V[1, 2]: Dimethylsulphide and tetrahydrothiophene complexes of niobium(IV) and tantalum(IV) halides

摘要: The tetrahalides NbCl4, NbBr4, TaCl4 and TaBr4 react with dimethylsulphide tetrahydrothiophene to form complexes of empirical formula MX4,2L, except in the case reaction niobium(IV) chloride which gave NbCl4,S(CH3)2. 1:2 adducts appear be normal pseudo-octahedral species whose magnetic spectral properties resemble those other tantalum(IV) adducts. moment far-i.r. spectrum S(CH3)2 suggest that this is structurally similar related d1 antiferromagnetic titanium (III) derivatives TiCl3,2S(CH3)2 TiCl3,2C4H8S. Two stoichiometry NbBr4,2C4H8S have been isolated, these may cis- trans- isomers. former soluble parent ligand whereas latter isomer insoluble.