Phosphorus phosphine

Dining removal of free iodine from hydriodic acid by distillation from red phosphorus, phosphine was produced. When air was admixed by changing the receiver flask, an explosion occurred. Omission of distillation by boiling the reactants in inert atmosphere, and separating the phosphorus by fitration through a sintered... 

Baudler and her co-workers have described in detail the preparation of larger quantities of phosphine by the hydrolysis of calcium phosphide. Higher phosphines (see page 51) formed simultaneously, are thermally decomposed to phosphorus, phosphine and hydrogen. It is noteworthy that, on storage in steel cylinders the diphosphine concentration in phosphine, originally less than 1%, increases. It is, even after several months, so small that the gas is not spontaneously inflammable in contact with air, whereas, after about one year, it is spontaneously inflammable. 

Table 7. N.M.R. data for phosphorus, phosphine and derivatives of phosphine...

Phosphine Phosphine (PH3), a colorless, extremely poisonous gas, is the most important hydride of phosphorus. Like NH3, phosphine has a trigonal pyramidal structure and has the group 5A atom in the —3 oxidation state. Unlike NH3, however, its aqueous solutions are neutral, indicating that PH3 is a poor proton acceptor. In accord with the low electronegativity of phosphorus, phosphine is easily oxidized, burning in air to form phosphoric acid ... 

Methods for Determining Parent Compounds and Degradation Products in Environmental Media. Few methods are available for the simultaneous determination of different forms of phosphorus (phosphine, elemental phosphorus, and metal phosphides) in environmental samples, and the methods are based on older technology (Gorzny 1972). It would be helpful to develop methods based on modem techniques for this purpose. It would also be useful to develop a few standard methods for analyzing different forms of phosphorus found in environmental samples. 

Ethyl dichlorophosphite is a colorless liquid, with an irritating odor. It fumes when exposed to air. It has the following physical constants sp. gr., 1.30526 b.p., 117.5° n °, 1.47176. It decomposes at 165° to ethyl chloride, phosphorus, phosphine, and phosphoric acid.3 It reacts with water to form hydrogen chloride and phosphorous acid, and with alcohols to form esters. When ammonia is passed through ethyl dichlorophosphite, ethyl phospheni-midate (ethoxyphosphimide), C2H5OP=NH, is formed. 

Many studies on the direct reaction of methyl chloride with silicon-copper contact mass and other metal promoters added to the silicon-copper contact mass have focused on the reaction mechanisms.7,8 The reaction rate and the selectivity for dimethyldichlorosilane in this direct synthesis are influenced by metal additives, known as promoters, in low concentration. Aluminum, antimony, arsenic, bismuth, mercury, phosphorus, phosphine compounds34 and their metal complexes,35,36 Zinc,37 39 tin38-40 etc. are known to have beneficial effects as promoters for dimethyldichlorosilane formation.7,8 Promoters are not themselves good catalysts for the direct reaction at temperatures < 350 °C,6,8 but require the presence of copper to be effective. When zinc metal or zinc compounds (0.03-0.75 wt%) were added to silicon-copper contact mass, the reaction rate was potentiated and the selectivity of dimethyldichlorosilane was enhanced further.34 These materials are described as structural promoters because they alter the surface enrichment of silicon, increase the electron density of the surface of the catalyst modify the crystal structure of the copper-silicon solid phase, and affect the absorption of methyl chloride on the catalyst surface and the activation energy for the formation of dimethyldichlorosilane.38,39 Cadmium is also a structural promoter for this reaction, but cadmium presents serious toxicity problems in industrial use on a large scale.41,42 Other metals such as arsenic, mercury, etc. are also restricted because of such toxicity problems. In the direct reaction of methyl chloride, tin in... 

Compounds of Gold and Phosphorus.—Phosphine reacts with a solution of auric chloride in anhydrous ether, forming auric phosphide, AuP, a substance decomposed by water or potassium-hydroxide solution, with formation of phosphine and phosphoric add.2 At 100° to 110° C. it-undergoes oxidation in the air. Heating in a current of carbon dioxide causes volatilization of phosphorus. Nitric acid oxidizes the phosphorus, leaving a residue of metallic gold. These reactions indicate the substance to be an alloy of gold and phosphorus. 

Transparent monoclinic crystals or colorless liquid. Very poisonous/ dj 2.135, mp 23.8. bp 173.1 in nitrogen atm. proportionates into red P and P304 when heated above 210. Sol in benzene, carbon disulfide. When placed in cold water, HjPOj is formed slowly. Hot water produces a violent reaction with the formation of ted phosphorus, phosphine, and HsP04. 

Asymmetric hydrogenation. Morrison et al. have reported on asymmetric hydrogenations catalyzed by rhodium(I) complexes of the Wilkinson type containing chiral ligands. This type of asymmetric synthesis had been carried out previously with relatively inaccessible phosphine ligands that are asymmetric at phosphorus. Phosphines that are asymmetric at carbon are more readily available and appear to be more efficient. Thus reduction of (E)- 3-methylcinnamic acid with prereduced tris(neomenthyldiphenylphosphine)chlororhodium in the presence of triethylamine leads to 3-phenylbutanoic acid, +34.5°, which contains 61% enantiomeric excess of the S-isomer. Hydrogenations of olefins exhibit a lower degree of asymmetric bias. 

Alkylation at Phosphorus. Phosphines and phosphites undergo easy quaternization. Thus methylation of tris(2,6-dimethyl-phenoxy)phosphine with MeOTf, followed by treatment of the product with sodium 2,6-dimethylphenoxide, gave methyltetrakis (2,6-dimethylphenoxy)phosphane. Methoxyphosphonium tri-flates are relatively stable intermediates in Arbuzov reactions Phosphine oxides and sulfides are alkylated. S-Methylation of chiral phosphine sulfides, followed by treatment with hexam-ethylphosphorous triamide, has been advocated as a general synthesis of optically active phosphines. ... 

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