Vanadium oxychlorides

The volatile chlorides ate collected and the unreactedsohds and nonvolatile chlorides ate discarded. Titanium tetrachloride is separated from the other chlorides by double distillation (12). Vanadium oxychloride, VOCl, which has a boiling point close to TiCl, is separated by complexing with mineral oil, reducing with H2S to VOCI2, or complexing with copper. The TiCl is finally oxidized at 985°C to Ti02 and the chlorine gas is recycled (8,11) (see also... 

In the production of titanium, the chlorination of rutile generates approximately 0.12 tons of waste for every ton of titanium tetrachloride produced. If ilmenite is directly chlorinated, the amount of waste is 1.5 tons for every ton of titanium tetrachloride. Large amounts of ferric chloride are produced along with volatile chlorides and oxychlorides (e.g., aluminum trichloride, silicon tetrachloride, carbon oxychloride, tin tetrachloride, vanadium tetrachloride, vanadium oxychloride) these can be removed by selective distillation. In flu-idized-bed chlorination, the build-up of liquid calcium chloride and magnesium chloride in the fluid bed interferes with the process of fluidization and hence these must be removed. 

Ethylene-propylene (30-60 mole per cent) copolymers produce substances which are rubbery in nature. They are prepared by using Ziegler catalysts based on vanadium oxychloride/aluminium trihexyl by solution process at 40°C using chlorobenzene or pentane as a solvent. These can be vulcanised with peroxides. Ethylene-propylene-hexa 1, 4-diene terpolymers are rubbers which can be vulcanised with sulphur. 

Dibenzothiophene derivatives have been used as co-catalysts in the addition polymerization of vinyl and diene monomers. Dibenzothiophene itself, in conjunction with vanadium oxychloride, is effective in initiating the polymerization of isobutylene, - although when incorporated in a Ziegler catalyst system, competition between donor and monomer for the most electrophilic sites results in deactivation of the catalyst. Despite the fact that 2-vinyl- - - and 4-vinyldibenzothiophene - readily undergo thermal polymerization,... 

To investigate the effect of the synthesis method on the structure-reactivity relationship of the supported metal oxide catalysts, a series of V205/Ti02 catalysts were synthesized by equilibrium adsorption, vanadium oxalate, vanadium alkoxides and vanadium oxychloride grafting [14]. The dehydrated Raman spectra of all these catalysts exhibit a sharp band at 1030 cm characteristic of the isolated surface vanadium oxide species described previously. Reactivity studies with... 

Preparation of Vanadium Oxychloride and Studying of Its Properties. Preparation of Vanadium Oxychloride by Roasting a Mixture of Vanadium(V) Oxide with Charcoal in a Chlorine Stream. Prepare a fine mixture of 5 g of vanadium(V) oxide, 3 g of charcoal, and 5 g of dextrin. Add water dropwise to the mixture until a paste... 

When the chlorination process terminates, stop the heating, cool the apparatus in a chlorine stream to 300-400 °C, and displace the chlorine from the apparatus with carbon dioxide. Disconnect the receiver and rapidly close it with a weighed stopper. Weigh the receiver with the vanadium oxychloride and calculate the yield in per cent. 

Remove the stopper from receiver 2 and introduce copper shavings. Close the flask with a stopper provided with a dephlegmator and thermometer (see Fig. 20). Wrap the flask in asbestos and put it into an electrical flask heater. What is the boiling point of vanadium oxychloride Transfer the collected liquid into a weighed drawn out test tube. (Wear eye protection, seal the substance in the presence of your instructor ) Weigh the ampoule with the remaining part of the tube. Calculate the yield in per cent. 

Hydrolysis of Vanadium Oxychloride. (Perform the experiment in a fume cupboard ) Pour 3-4 ml of water into a bowl and add several drops of vanadium oxychloride. What occurs ... 

Preparation of Vanadium Oxychloride by Reacting Vanadium(V) Oxide with Thionyl Chloride. Place 16 g of ammonium vanadate into a porcelain crucible. Roast the substance up to a constant mass at 500-550 °C in a crucible furnace, passing oxygen into the latter via a glass tube from a gas meter. 

The effect of nucleophilic dienes on the copolymerization of ethylene and propylene has been reported by Gladding, Fisher and Collette (88). Table 8 shows that 1.4-hexadiene decreased the tendency for propylene to enter into the ethylene-propylene terpolymer, produced by a triisobutyl aluminum-vanadium oxychloride catalyst. 

Uses. The most important commercial use for benzonitrile is the synthesis of benzoguanamine, which is a derivative of melamine and is used in protective coatings and molding resins (see Amino RESINS Cyanamides). Other uses for benzonitrile are as an additive in nickel-plating baths, for separating naphthalene and alkylnaphthalenes from nonaromatics by azeotropic distillation (qv), as a jet-fuel additive, in cotton bleaching baths, as a drying additive for acrylic fibers, and in the removal of titanium tetrachloride and vanadium oxychloride from silicon tetrachloride. 

In reporting a Ziegler-Natta catalyst, the kind of transition metal compound should not be omitted. Group 4-8 transition metal compounds, such as halides, oxyhalides, alkoxides, acetylacetonates, etc., have been used as catalyst precursors with activators such as alkyl derivatives or hydrides of group 1-4 metals. Titanium chlorides and triethylaluminium are most commonly applied for the preparation of heterogeneous catalysts in an aliphatic hydrocarbon medium. Also, vanadium oxychloride or acetylacetonate and dialkyaluminium chloride are often used for the preparation of homogeneous catalysts in an aliphatic hydrocarbon or an aromatic hydrocarbon medium. 

A biomimetic synthesis(165) of ( )-2-hydroxycodeine (69) has been reported, in 37% yield, by the vanadium oxychloride phenolic coupling of a 1-benzyltetrahydroisoquinoline with a symmetrical 3,5-dihydroxy-4-methoxy-substitution pattern in the benzyl ring. 

The general kinetic features of the polymerization show the rate to be first order in monomer and vanadium oxychloride concentrations, and independent of Al/V ratio above 5/1. The rate was increased in the presence of the polar solvent up to THF/V = 6 but then became independent of THF concentration. The catalyst underwent a rapid decomposition, accounting for declining polymerization rates with time, which was shown to be second order. The rate coefficient for decompo-... 

In the chloride process natural rutile ore or synthetic rutile with a Ti02-content of up to 96% is chlorinated in a fluidized bed reactor with oil-coke and chlorine. The raw TiCl4 produced is mixed with reducing agents to convert impurities, such as vanadium oxychloride, to lower valency state vanadium compounds. The titanium tetrachloride formed is then distilled yielding titanium tetrachloride in... 

Figure 1. The vanadium oxychloride concentration in the gas flow influence on the chemisorbed amount. Gas flow rate 0.05 m/s reaction time 1 7200 s, 2 - 900 s, 3 420 s, 4 - 180 s.

The temperature regulation in the desorption stage can result in its essential intensification, as shown by the study of reaction of vanadium oxychloride with silica [48]. But it is necessary to take into account the properties of surface groups, in particular, their thermal stability. The latter, as it is known from the papers [49,50], can essentially influence the structural conversions of solid matrix. 

OXIDATIVE PHENOL COUPLING Ferric chloride. Silver carbonate. Vanadium oxychloride. Vanadium tetrachloride. 

Intramolecular oxidative phenol coupling. The 1,3-bis(hydroxyphenyl)pro-pane (1) is converted into the phenolic dienone (2) in 76% yield by reaction with 2.5 molar equivalents of vanadium oxychloride in refluxing ether (10 hours).1 Use... 

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