Vanadyl chloride, reaction

Vanadium Oxytrichloride, VOCl3, commonly known as vanadyl chloride, is the easiest to prepare of all the halogen or oxyhalogen compounds of vanadium. It distils over as a yellow liquid when vanadium pentoxide is strongly heated, or when vanadiun trioxide is gently heated, in a current of chlorine. Addition of charcoal accelerates the reactions 9... 

Vanadium phthalocyanine (PcVO) is prepared from vanadium(IIl) chloride in a melt of phthalonitrile228 to which sometimes ammonium vanadate137 or molybdate229 and urea are added. Also a reaction with vanadium(V) oxide and phthalonitrile in pen tan-1-ol has been performed.230 Besides these direct syntheses, transformation of PcH2 to PcVO in refluxing dimethylformamide with vanadyl sulfate (V0S04) has been carried out.231... 

In Table 5 the values for the free standard enthalpies for the reactions of neutral donors and anion donors with vanadyl acetylacetonate are listed. It can be seen that towards the reference molecule iodide ion is a somewhat weaker ligand than propanediol carbonate, whereas the bromide ion is between tri-methylphosphate and acetone, and the chloride ion between DMF and DMSO 22>. The fluoride ion and the NCS -ion are stronger donors than all neutral donors but are somewhat weaker than the azide and the cyanide ion. 

Light accelerated all reactions, but the order found for reactivity in the dark, chlorine - sulfuryl chloride > t-butyl hypochlorite > dinitrogen tetroxide t-butyl hydroperoxide - benzoyl peroxide - azobisiso-butyronitrile > bromine, was still maintained. When light entering the reaction mixture was filtered through a solution of vanadyl etioporphyrin I, the resulting radiation produced no acceleration. 

The metalloporphyrin cation-radical would likely react with the radical derived from the reagent, with substitution occurring at a meso-position, leading to the formation of a resonance-stabilized carbonium ion of the metalloporphyrin. That substitution occurs in the meso-positions is suggested by the observation that one of the major fractions obtained from the reaction of vanadyl octaethylporphine with sulfuryl chloride contained no methine protons, as demonstrated by the nmr spectrum. The site of substitution being meso is further supported by the fact that reactions of metalloporphyrins with peroxides and bromine provide meso-substituted products. Electro-... 

In the present contribution, we describe the preparations of several binary transition metal tosylates directly from the metal and p-toluenesulfonic acid under an inert atmosphere. This method is easy to carry out, and affords products that are completely free of contaminating counterions. The presence of excess metal provides a reducing environment, so that divalent products are obtained for all first-row transition metals except for Ti and V, which form trivalent products under these reaction conditions. The Cr° salt may be converted to Cr (OTs)3 by air oxidation in the presence of excess p-toluenesulfonic acid. Tosylate salts of Ti, V, Fe, and Cs can also be prepared by treatment of the corresponding metal chloride with p-toluenesulfonic acid, and a vanadyl salt has been prepared by similar treatment of vanadyl acetylacetonate. 

Based on the experimental results and taking into account the coordination properties of vanadyl ions (niobium s closest analogue) in alkali chlorides [19] we assume that NbOCl4 chloride complexes are formed as intermediates in reactions of NbO and Nb02 with hydrogen chloride. 

---