Formation of Phosphine

Several laboratory explns have occurred when using the reaction between P trichloride and acetic acid to form acetyl chloride. Poor heat control probably caused formation of phosphine (Ref 2). Two later explns may have been due to ingress of air and combustion of traces of phosphine (Ref 8). Al powder burns in P trichloride vapor (Ref 4) K ignites and molten Na explds on contact (Ref 3). Each drop of chromyl chloride added to well-cooled P trichloride produces a hissing noise, incandescence, and sometimes an expln (Ref 5). It reacts with fluorine with incandescence (Ref 1), and with ignition... 

Change in the way a reaction occurs because of inappropriate temperatures. At 20 C nitric acid converts mesitylene into 3,5-dimethylbenzoic acid without danger, but at 115°C the explosive 1,3,5-tris(nitromethyl)benzene is formed. Excessive heating of thiophosphoryl trichloride with pentaerythritol at 160°C leads to the formation of phosphine, which combusts spontaneously. 

Zinc phosphide can combust in contact with water probably because of the formation of phosphine. Finally, it reacts violently with perchloric acid. 

It is possible to make an acid chloride by the action of phosphorus trichloride on an acid. Three accidents have been described that involved the action of this compound on acetic, propionic and 2-furoic acids, respectively. This was explained by the formation of phosphine due to excessive heating that led to the decomposition of the phosphorus acid formed ... 

Anthryl, 1-naphthyl, mesityl, and 4-quinolyl groups in 37h-k promote C/C aryl shift (see Table 2) their proclivity to migrate is far greater than expected from the electronic influence of the x-systems. This is presumably due to the intermediacy of spiro-linked benzenium betaines 30 31 , occurring in place of the carbenes otherwise encountered. The formation of phosphinic esters 42h-k is partly or completely suppressed 30). 

Flash fires and explosions which frequently occurred on discharge of the hot products of catalytic hydrogenation of vegetable oils were attributed to formation of phosphine from the phosphatides present to a considerable extent in, e.g., rape-seed and linseed oils. 

A fibre drum of the salt ignited spontaneously. This was attributed to slow decomposition with formation of phosphine which accumulated and eventually ignited inside the drum. 

Nickel and palladium complexes also catalyze the formation of the carbon-phosphorus bonds in phosphorus(V) and phosphorus(III) compounds. Indeed, this chemistry has become a common way to prepare phosphine ligands by the catalytic formation of phosphine oxides and subsequent reduction, by the formation of phosphine boranes and subsequent decomplexation, or by the formation of phosphines directly. The catalytic formation of both aryl and vinyl carbon phosphorus bonds has been accomplished. 

Some hydrogenation techniques may induce surface damage that increases the H concentration at the surface. Some of the compounds tend to decompose during hydrogenation for example, the surface of InP decomposes with the formation of phosphine (PH3). This problem has been controlled by encapsulating the substrate with a hydrogen-permeable layer. 

In the particular case of InP, protection of the surface is necessary because direct exposure of an InP sample to a rf hydrogen plasma causes a strong surface decomposition with the formation of phosphine and metallic indium islands (Thomas et al., 1988). Hydrogen diffusion into InP Zn can be successfully performed through an undoped correctly lattice matched... 

Reaction of 3 with 1 equivalent of a phosphine results in formation of "phosphine-modified catalysts (4). The complex formed from 7r-allyl-nickel chloride, tricyclohexylphosphine, and methylaluminum dichloride (4a) has been isolated and its structure determined crystallographically (see Fig. 1) (57) The phosphine is bonded to the nickel atom, and interaction with the Lewis acid takes place via a chlorine bridge. The bridging chlorine atom is almost symmetrically bound to both the nickel... 

Tertiary phosphines are oxidized catalytically by nickel(O) complexes with formation of phosphine oxides. Also, complexed tert-butylisonitriles can be oxidized to the corresponding isocyanates (examples 1 and 2, Table IX) (225-226). 

Furthermore, even the ligand, necessary to stabilize the catalyst, can reduce Pd(II) to Pd(0) complexes and formation of phosphine oxides [62-64], In the preparation of [Pd(AcO)2(dppp)], from Pd(AcO)2 and dppp in MeOH, phosphine oxides have been found to form together with methyl acetate and palladium metal [65]. The reaction can be schematized as follows ... 

CH3CN/H2O solution leads to various tertiary phosphines [33] examples include 1, 25, 27. In order to avoid the formation of phosphine oxides and/or the hydrolysis of some alkene derivatives (e.g. acryl esters) a small amount of Et4N Oir was used as base, and a small quantity of ditertbutylphenol was... 

Revisions of earlier data on the heat of formation and the bond energies of phosphine have been undertaken The heat of formation of phosphine from white phosphorus and hydrogen is 1.30kcal/mol (the corresponding value for P2H4 is 5.0 1.0 kcal/mol), the average bond energy E (P—H) was found to be 76.8 kcal. 

Spectacular proof of the existence of arylphosphinidines has been provided by Caspar and co-workers and Weissman et al. A frozen solution of 71 in methyl-cyclohexane glass was exposed to 254-nm radiation. The glass turned yellow upon photolysis. Thawing the glass led to the formation of phosphine 72 in the absence of trap, and to the formation of 73 in the presence of 3-hexyne. When the frozen, previously irradiated sample was placed in an EPR spectrometer a triplet signal at... 

A systematic and methodical study to prevent or retard formation of phosphine has been carried out by Hoerold and Ratcliff of Clariant GmbH, Germany and their findings through the following approaches are reproduced here [45]. 

CA 32,2355( 1938)(Explns take place sometimes during this method of prepn. Coghill attributes the formation of phosphine, PH, as the cause of such expins)... 

W. Ipatieff and W. Nikolaieff observed the formation of phosphine when white phosphorus is heated with hydrogen in a sealed tube at 360° and when water-gas at 400 atm. press, acts on lead phosphate. J. Brossler said that if white phosphorus be added to a mixture of zinc and dil. sulphuric acid, in a short time, spontaneously inflammable phosphine will be produced and if a cone. soln. of alkali hydroxide and zinc be mixed with yellow phosphorus, the spontaneously inflammable gas will be given off at about 60° if the temp, be below 20°, the gas evolved is not spontaneously inflammable. H. Davy, and L. Dusart showed that the gas obtained by the action of zinc and dil. acids on yellow phosphorus contains phosphine, although J. B. A. Dumas questioned the fact. D. Vitali observed that the presence of mercuric chloride retards the formation of phosphine. J. Brossler obtained phosphine by the action of hydrochloric acid and a few drops of nitric acid on tin in the presence of yellow phosphorus. The formation of phosphine during the action of ammonia, and of water on yellow phosphorus has been indicated in connection with the chemical reactions of phosphorus. 

RT log K, where K—pmJPp Pvi- The free energy of the formation of phosphine from hydrogen and solid phosphorus at 25° is —3296-0 cals. The entropy change in the reaction calculated from the free energy equation is —27-72 so that the entropy of phosphine at 25° is 52-4 units. J. C. Thomlinson compared the heats of formation of the trihydrides of the nitrogen-antimony family of elements. 

Phosphine, a highly toxic gas, is generated from phosphide. The rate of formation of phosphine (permissible exposure limit [PEL], 0.4 mg/m3) is dependent on the ambient temperature and humidity. In the presence of water (humidity) or acid, the formation of phosphine is greatly enhanced at any given temperature. Phosphine is released rapidly, and... 

Ethyl Alcohol. Acetyl chloride reacts violently with ethyl alcohol.5 Phosphorus Trichloride with Acetic Acid. Several laboratory explosions have occurred using this reaction to form acetyl chloride. Poor heat control probably caused formation of phosphine.6... 

The mechanism of action of the phosphonium halides as flame retardants also may be related to the formation of phosphine oxides and/or phosphinic acids from the halide, according to the following reactions (8,14,17). 

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