Molybdenum -oxide chloride

Molybdenum Oxides. Molybdenum was one of the first elements used to retard the flames of ceUulosics (2). Mote recently it has been used to impart flame resistance and smoke suppression to plastics (26). Molybdic oxide, ammonium octamolybdate, and zinc molybdate ate the most widely used molybdenum flame retardants. Properties ate given in Table 5. These materials ate recommended almost exclusively for poly(vinyl chloride), its alloys, and unsaturated polyesters (qv). 

The high-density polyethylene is linear and can be manufactured by (i) coordination polymerisation of monomer by triethyl aluminium and tritanium chloride, (ii) polymerisation with supported Metal Oxide Catalysts. Such as chromium or molybdenum oxides supported over alumina-silica bases. 

The solvent process involves treating phthalonitrile with any one of a number of copper salts in the presence of a solvent at 120 to 220°C [10]. Copper(I)chloride is most important. The list of suitable solvents is headed by those with a boiling point above 180°C, such as trichlorobenzene, nitrobenzene, naphthalene, and kerosene. A metallic catalyst such as molybdenum oxide or ammonium molybdate may be added to enhance the yield, to shorten the reaction time, and to reduce the necessary temperature. Other suitable catalysts are carbonyl compounds of molybdenum, titanium, or iron. The process may be accelerated by adding ammonia, urea, or tertiary organic bases such as pyridine or quinoline. As a result of improved temperature maintenance and better reaction control, the solvent method affords yields of 95% and more, even on a commercial scale. There is a certain disadvantage to the fact that the solvent reaction requires considerably more time than dry methods. 

Poly (vinyl chloride). PVC is a hard, brittle polymer that is self-extinguishing. In order to make PVC useful and more pliable, plaslict/ers I qv) are added. More often than not the plasticizers are flammable and make Ihe formulation less flame-resistant. The Maine resistance of the polyf vinyl chloride) can he increased by ihe addition of an inorganic llamc-rctardunl synergist, e.g., antimony oxide, mixed metal antimony synergists, zinc borate, molybdenum oxide, zinc stannates. and alumina trihydrale. 

Syntheses of MPc from phthalodinitrile or phthalic anhydride in the presence of urea are the two most important laboratory and industrial methods. They were also used originally by Linstead et al. [8,9], This procedure allows the production of many phthalocyanine compounds [35-37], Catalysts such as boric acid, molybdenum oxide, zirconium and titanium tetrachloride, or ammonium molybdate are used to accelerate the reaction and improve the yield [36,37], Ammonium molybdate is especially effective. Reaction is carried out either in a solvent or by heating the solid components. When metal chlorides and phthalodinitrile are used as starting materials, the reaction products are partially chlorinated (e.g.,7). 

The preparation of pure molybdenum(IY) chloride is complicated by its extreme ease of disproportionation and oxidative instability. Formerly, the preparation of the tetrachloride was Arizona State University, Tempe, Ariz. 85281. 

Molybdenum oxide trichloride has been prepared by heating molybdenum(VI) oxide or molybdenum dioxide dichloride with molybdenum(V) chloride. Molybdenum(VI) oxide tetrachloride is a by-product of the latter reaction.1 It was also prepared by the sealed-tube reaction of liquid sulfur dioxide with molybdenum (Y) chloride2 and by the thermal decomposition of molybdenum oxide tetrachloride in a stream of nitrogen. In the following procedure, it is prepared by reducing molybdenum oxide tetrachloride with refluxing chlorobenzene.4... 

Despite this they should be considered as possible alternatives in cases where more familiar methods fail. Amongst this group of activators are p-toluenesulfonyl chloride, tiifluoromethanesulfonic anhy-dride,silver tetrafluoroborate, molybdenum oxide, phosphorous pentoxide, trichloromethyl chloroformate, 2-fluoro-l-methylpyridiniumsulfonate, chlorosulfonyl isocyanate, antimony penta-chloride (for which an X-ray structure of the DMSO-SbCb conqilex was obtained) and phenyl dichlo-rophosphate. ... 

Dimethyldioxirane (1) is a mild and efficient oxidant for pyridine pyiidines and quinolines have also been oxidized in good yield by r-pentylhydroperoxide in the presence of molybdenum(V) chloride. A(-Halogenation and other oxidative reactions of pyridines and related heterocycles have been re-viewed. " Thus, pyridines and some diazines can be aminated by mesitylenesulfonylhydtoxylamine... 

Dimethyldioxirane (1) is a mild and efficient oxidant for pyridine pyridines and quinolines have also been oxidized in good yield by r-pentylhydroperoxide in the presence of molybdenum(V) chloride. 

The hexafluorides of molybdenum and tungsten arc volatile liquids (respective b.p. 35.0° and 19.6°), readily hydrolysed to molybdic and tungstic acids. WClg is a solid. The metals form oxide chlorides, MO.,Cl2. Chromyl chloride, familiar as a distinguishing test for a chloride, appears as a yellow distillate on heating a chloride with KgCrgO and concentrated H2SO4 ... 

The role played by coordination complexes as templates and catalysts in these reactions is somewhat more difficult to discern, although several important results have been reported. Some early work by Bahadur showed that amino acids were formed in the reaction of potassium nitrate with paraformaldehyde in the presence of light. Many amino acids were produced, but the highest yields were found when the reaction was carried out in the presence of iron(lll) chloride as a catalyst. Later work extended analogous findings to colloidal molybdenum oxide as the catalyst. Molecular nitrogen was fixed in this case, a reaction in a sense comparable to the... 

N-OXIDES Diphosphorus tetraiodide. Hexachlorodisilane. Molybdenum(V) chloride-Zinc. Titanium(IV) chloride-Sodium borohydride. 7... 

Shapoval asserted that they observed a blue colouration of the melt containing molybdenum oxide, which seemingly arose owing to partial reduction of Mo03 to lower oxidation degrees of molybdenum with the simultaneous oxidation of chloride ions to chlorine, which evaporated from the melt. The molybdenum oxides formed were of the general composition Mo 03 i. 

V.L Shapoval, A.S. Avaliani and N.A. Gasviani, Acidic Properties of Molybdenum Oxide in Molten Chlorides, Soobsch. AN Graz. SSR 72 (1973) 105-108. 

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