Vanadium chloride, adduct with

The reactions between TiCl., TiBr., TiCl, VCl, VCl, and VBr with a range of monodentate sulphur ligands, have been investigated. The ligands used include the aliphatic thioethers, R S, for R =Me, Et, Pr, and Bu, and tetrahydrothiophen and pentamethylenesulphide. Notable differences have been observed in the reactions of the halides of the two elements. Thus, whereas the tetrahalides of titanium form simple adducts with all ligands tried, vanadium(IV) chloride is reduced rapidly and quantitatively to the tervalent state. Furthermore, tervalent vanadium forms a series of well-defined complexes with sulphur ligands, but the complexes formed by tervalent... 

The products formed in the reactions of the vanadium chlorides with the dialkyl sulphides (R = Me and Et) have the composition VCySR ]. These compounds are monomeric in benzene solution and have dipole moments of about 2, 5 D. On the basis of the spectroscopic evidence, and by analogy with the trimethylamine adducts (VX (NMe ) these compounds have been assigned trans-trigonal-bipyramidal structures. Their visible and ultra-violet spectra have been measured and the significance of these results will be discussed. 

Improved syntheses of bitropyl and sym-tetrabenzobitropyl have been reported whereby tropylium tetrafluoroborate and dibenzotropylium tetrafluoroborate, respectively, are coupled using vanadium(ii) chloride or titanium(iii) chloride. Trimethylene-8,8-dithiaheptafulvene (125), an electron-rich heptafulvene, has been prepared from the adduct of 2-lithio-l,3-dithian and tropylium tetrafluoroborate, and its reactions with reactive dienophiles have been examined. " The sym-dibenzo analogue of (125) has also been described.anti-[2,2] (2,6)-Azulenophane has been prepared by the dimerization of (126). ... 

Reactions of metal halides with ammonia may involve the formation of addition compounds or bring about ammonolysis of one or more of the metal-halogen bonds . The dichlorides of manganese, iron, cobalt and nickel form adducts. Vanadium(III) chloride and vanadium(III) bromide are ammonolysed in liquid ammonia to a mixture of ammonolysis products with the same chemical composition as that of the previously reported hexamine ... 

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