Oxytrichloride

Vanadium oxytrichloride has usually been prepared by the chlorination of vanadium(III) oxide, either alone or mixed with a reducing agent such as carbon.1 The method of preparation described below avoids the use of free chlorine and the potentially hazardous distillation from sodium, which are the most undesirable features of the classical method further, it requires only a minimum amount of apparatus. 

Vanadium oxytrichloride is a lemon-yellow liquid with a boiling point of 127°1,2 and a freezing point of — 79.5°.2 Vapor-pressure data are also given in reference 2. Its chemical properties are those to be expected of a covalent, anhydrous metallic halide. It is very readily hydrolyzed and should be protected from moisture at all times. If the liquid has been exposed even briefly to moisture, its color will be orange or red, and it will contain an orange-red precipitate. 

A pyrex tube 100 cm. long and about 2.5 cm. in diameter is filled to one-third of its capacity with vanadium pent-oxide. After the air has been displaced with hydrogen, the tube and its contents are heated to a dull-red heat. A slow stream of hydrogen is allowed to flow until the mixture in the tube becomes black. Heating is then discontinued, but hydrogen is passed through the tube until its contents are cool. 

The black oxide of vanadium is mixed with an equal weight of Norite which has been activated and dried by heating to as high a temperature as possible without ignition. The pyrex tube is refilled with the dried mixture so 

The product is colored red by the presence of vanadium tetrachloride and contains considerable dissolved chlorine. These impurities may be removed by fractional distillation followed by a distillation from metallic sodium. The last few milliliters of vanadium oxytrichloride should not be removed from the sodium by a direct flame, as superheating often causes an explosion. A fractionating udder is convenient for collecting the product without exposing it to the moisture in the air. The side tube should be connected to a drying tube. Yield 70 g. (87 per cent of theory) boiling point 124.5 to 125.5° at 744 mm. 

Vanadium oxytrichloride is a lemon-yellow liquid. Its boiling point is 124.5°C. at 736 mm. and 127.16°C. at 760 mm. It remains liquid at —77°. The vapor pressure at —77° is 4.1 mm. at 0°, 21 mm. and at 85°C., 270 mm. Its density in grams per milliliter is 1.854 at 0° and 1.811 at 32°C. At ordinary temperatures, it neither dissolves nor reacts with carbon, hydrogen, nitrogen, oxygen, silicon, tellurium, or metals except the alkali metals and antimony. The reactions with the alkali metals are explosive at characteristic temperatures, varying from 30°C. for cesium to 180°C. for sodium (lithium not determined). Small 

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Phosphoms oxyfluoride is a colorless gas which is susceptible to hydrolysis. It can be formed by the reaction of PF with water, and it can undergo further hydrolysis to form a mixture of fluorophosphoric acids. It reacts with HF to form PF. It can be prepared by fluorination of phosphoms oxytrichloride using HF, AsF, or SbF. It can also be prepared by the reaction of calcium phosphate and ammonium fluoride (40), by the oxidization of PF with NO2CI (41) and NOCl (42) in the presence of ozone (43) by the thermal decomposition of strontium fluorophosphate hydrate (44) by thermal decomposition of CaPO F 2H20 (45) and reaction of SiF and P2O5 (46). 

Most catalysts for solution processes are either completely soluble or pseudo-homogeneous all their catalyst components are introduced into the reactor as Hquids but produce soHd catalysts when combined. The early Du Pont process employed a three-component catalyst consisting of titanium tetrachloride, vanadium oxytrichloride, and triisobutjlalurninum (80,81), whereas Dow used a mixture of titanium tetrachloride and triisobutylalurninum modified with ammonia (86,87). Because processes are intrinsically suitable for the use of soluble catalysts, they were the first to accommodate highly active metallocene catalysts. Other suitable catalyst systems include heterogeneous catalysts (such as chromium-based catalysts) as well as supported and unsupported Ziegler catalysts (88—90). 

The second type of solution polymerization concept uses mixtures of supercritical ethylene and molten PE as the medium for ethylene polymerization. Some reactors previously used for free-radical ethylene polymerization in supercritical ethylene at high pressure (see Olefin POLYMERS,LOW DENSITY polyethylene) were converted for the catalytic synthesis of LLDPE. Both stirred and tubular autoclaves operating at 30—200 MPa (4,500—30,000 psig) and 170—350°C can also be used for this purpose. Residence times in these reactors are short, from 1 to 5 minutes. Three types of catalysts are used in these processes. The first type includes pseudo-homogeneous Ziegler catalysts. In this case, all catalyst components are introduced into a reactor as hquids or solutions but form soHd catalysts when combined in the reactor. Examples of such catalysts include titanium tetrachloride as well as its mixtures with vanadium oxytrichloride and a trialkyl aluminum compound (53,54). The second type of catalysts are soHd Ziegler catalysts (55). Both of these catalysts produce compositionaHy nonuniform LLDPE resins. Exxon Chemical Company uses a third type of catalysts, metallocene catalysts, in a similar solution process to produce uniformly branched ethylene copolymers with 1-butene and 1-hexene called Exact resins (56). 

Only vanadium(V) oxytrichloride (VOCl ) and the tetrachloride (VCl have appreciable commercial importance. The trichloride (VCl ) is of minor... 

Vanadium(V) Oxytrichloride. Vanadium(V) oxytrichloride (VOCl ) is readily hydrolyzed and forms coordination compounds with simple donor molecules, eg, ethers, but is reduced by reaction with sulflir-containing ligands and molecules. It is completely miscible with many hydrocarbons and nonpolar metal hahdes, eg, TiCl, and it dissolves sulfur. 

Halides and Oxyhalides. Vanadium(V) oxytrichloride is prepared by chloriaation of V20 mixed with charcoal at red heat. The tetrachloride (VCl is prepared by chlorinating cmde metal at 300°C and freeing the Hquid from dissolved chlorine by repeated freezing and evacuation. It now is made by chlorinating V20 or VOCl ia the presence of carbon at ca 800°C. Vanadium trichloride (VCl ) can be prepared by heating VCl ia a stream of CO2 or by reaction of vanadium metal with HCl. 

The development of a brown color indicates that sufl cient phosphorus oxytrichloride has been added. If the mixture remains colorless, the final product is likely to be contaminated with unreacted iV-( -tolylsulfonylmethyl)formamide. It is therefore advantageous to add more phosphorus oxjrtrichloride and continue stirring until the brown color is obtained. 

MA -Dimethylamino)phenyl]-2-ethylpropenal (5) was produced by reaction of A, A -dimethyl-aniline (/) with 2-ethyl-3-ethoxyacrolein (2) in the presence of phosphorus oxytrichloride. 

Cyclodehydration of 3-carboxymethylsulfanyl-l,2,4-triazoles 305 (R = Het, HetCH2) with a mixture of acetic acid/ acetic anhydride, or phosphorus oxytrichloride, yields 5,6-dihydrothiazolo[3,2-Z ][l,2,4]triazol-5(6//)-oncs 185 (Equation 49) <1998PHA94, 1998IJH231, 2003PS(178)2431>. 

Pentoxide when heated with chlorine gas at 500°C in the presence of carbon forms vanadium oxytrichloride ... 

The most common method for achieving aromatization of compounds such as 72 is with phosphorus oxytrichloride and the addition of dimethylformamide (DMF Scheme 1) (see, for example, <1996CHEC-II(7)921>, and more recently, <2004M283, 1997S567>). Reductive dechlorination of 73 with palladium on carbon in the presence of sodium hydroxide affords the corresponding heterocycle 74 (Scheme 1) <2004M283>. 

Commercial phosphorus oxytrichloride ( tout pur from UCB, Belgium) was used without purification. 

Phosphorus oxytrichloride. Ethylene dichloride, Dimethylamine, Sodium carbonate, Sodium fluoride. Ethyl alcohol. Chloroform, Petroleum ether Phosphorus oxytrichloride. Ethylene dichloride, Dimethylamine, Sodium carbonate, Sodium cyanide. Ethyl alcohol. Acetonitrile, Pyridine... 

Phosphorus oxytrichloride. Ethylene dichloride, Dimethylamine, Sodium carbonate, Sodium cyanide. Ethyl alcohol. Acetonitrile... 

Phosphorus oxytrichloride. Benzene, Neopentyl glycol, Pyridine, Petroleum ether, Ammonium fluoride... 

Nitric acid. Sulfuric acid, N-Methylhydroxy acetamide Phosphorus oxytrichloride. Benzene, Neopentyl glycol. Pyridine, Petroleum ether. Ammonium fluoride Thiophosphorus trichloride. Benzene, Neopentyl glycol. Pyridine, Petroleum ether. Ammonium fluoride Nitric acid. Sulfuric acid. Glycerol, Magnesium sulfate Anhydrous hydrazine. Cyanogen bromide. Isopropyl alcohol. Sodium nitrite. Sodium bicarbonate. Copper nitrate trihydrate. Nitric acid. Diethyl ether... 

By the action of water upon phosphoric chloride and phosphoric oxytrichloride (see pp. 112 and 118). 

Urea Peroxide Urea Peroxide Hexamethylenetetramine Hexamethylenetetramine Antimony Trioxide Valeraldehyde Valeraldehyde Valeraldehyde Vinyl Acetate Vanadium Pentoxide Vanadyl Sulfate Vanadium Oxytrichloride Vanadium Pentoxide Vanadium Pentoxide Vanadium Oxytrichloride Vanadyl Sulfate Vanadyl Sulfate Vanadium Oxytrichloride Captan... 

Vanadyl Azide Trichloride. V0(N3)C13, G3N3OV mw 215.33 cryst. Sol in V oxytri-chloride. Prepn is by bubbling a mixt of chlorine azide and nitrogen thru V oxytrichloride at RT. The compd deflagrates with great vigor on being subjected to thermal shock (Ref 17)... 

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