Hydrides phosphorus

Phosphine, PH3, is a very reactive and poisonous gas, it tends to inflame spontaneously in air and has been described as smelling of both garlic and rotten fish PH3 is much less basic than NH3, as the P—H bond is much less polar than the N—H bond. Unlike ammonia, phosphine does not form hydrogen bonds. Although phosphonium salts, [PH4]+X , are known, only PH4I is stable at room temperature the other phosphonium halides dissociate to PH3 and HX. 

Phosphine may be prepared by the hydrolysis of the phosphides of electropositive metals, such as calcium phosphide  

Two isomers of P7H3, which arise from different orientations of hydrogen atoms and non-bonded pairs of eleetrons on the three phosphorus atoms in the middle of the cage. 

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Phosphorus hydride (Phosphine) (PH3) Pyrophoric Very slow... 

The phosphorus hydride which is formed combusts in contact with the oxygen that... 

This would explain the fact that groups which form stable radicals, e.g., benzyl, allyl, or phenacyl, are easiest to remove electrolytically, and that tertiary alkyl groups are removed more readily than secondary or primary. This mechanism is more likely than one previously suggested, which involves a pentacoordinate phosphorus hydride ( 70) 61 > ... 

A new approach to piperidines via cyclization of dienes, such as 158, employs a phosphorus hydride mediated radical addition/cyclization reaction <06JOC3656>. This reaction proceeds with complete regioselectivity to create the 6-exo-trig product 159, although as an inseparable mixture of two of the four possible diastereomers. 

Solid Phosphorus hydride , 4449 Silicon monohydride, 4451 f Stibine, 4510... 

Hz) are observed for a cis-phosphorus-hydride coordination mode. If there is fast exchange of the phosphorus ligands between the equatorial and apical positions, an averaged resonance and coupling constant are observed for the equilibrium mixture of the ee and ea isomers. 

Table 1. Bond lengths and bond angles in the phosphorus hydride molecule and some of its derivatives (from Corbridge 3 ))...

Royen and Hill reported that phosphonium bromide and solid phosphorus hydride are the products from the reaction of excess phosphine with bromine at low temperatures. 

Only polymeric phosphorus hydride, P H, and not red phosphorus was observed when phosphine was treated with chloramine in ether solution The authors attributed this to the expected higher basicity of a dimethylamino group in comparison to that of an amino group. 

The spontaneously inflammable nature of the higher phosphines decreases with increasing phosphorus content. At room temperature or on exposure to light, phosphorus-rich, yellow, solid phosphines are rapidly formed these can also be obtained directly by thermal decomposition of diphosphine. The literature on these types of higher phosphorus hydrides which are, in general, solid and are thus refered to as solid phosphorus hydrides is abundant and... 

The solid phosphorus hydrides are insoluble in all solvents generally used. They are relatively stable in air but are oxidised by strong oxidising agents. 

N. Blondlot said that red phosphorus is formed by the action of soln. of potassium, sodium, or ammonium hydroxide on ordinary phosphorus A. Commaille said that with aq. ammonia, some phosphorus hydride is formed—vide infra—and A. Stock and co-workers found that red phosphorus is produced by the aq. ammonia treatment. E. J. Houston considered the phosphorus produced by a protracted heating under potash-lye to be a special modification. B. Lepsius found that red phosphorus is formed when phosphine is decomposed by an electric arc and A. Stock and co-workers, when the solid hydride is heated in vacuo for 24 hrs. at 340°-360°. 

Hence, the formulae for the methyl compounds simultaneously represent the hitherto unknown structures of the phosphorus hydrides P H, P7Hg, PgH, and P H,. U, 2). Small differences between the hydrogen and methyl substituted phosphanes should exist only with respect to the relative amounts of the various configurational isomers. 

Sodium phosphides.—By heating in vacuum at 400° to 450° C. the black product formed by the interaction of sodium and phosphorus, a lemon-yellow substance of the formula Na2P5, is obtained.19 It has a density somewhat above 2, is unstable in air, and is decomposed by water with formation of solid phosphorus hydride. 

Potassium phosphides.-—Phosphine reacts with a solution of potassium in liquefied ammonia to form potassium dihydrophosphide, KH2P, white crystals decomposed by moist air with evolution of phosphine.1 On heating, it is converted into tripotassium phosphide, K3P. A solution of potassium in liquefied ammonia reacts with red phosphorus to form potassium pentaphosphide, KPfi.2 The black product formed from potassium and phosphorus loses its excess of metal in vacuum at 400° to 450° C., yielding dipotassium pentaphosphide, K2P5. It is a lemon-yellow substance with a density of about 2, is unstable in air, and is decomposed by water with formation of solid phosphorus hydride.3... 

Phosphorus forms many types of hydrides (7-9), called phosphanes (Table I). Phosphine (PH3) and diphosphine (H2P—PH2) are the best known. Phosphine is a colorless, toxic gas with a characteristic smell. The higher condensed phosphorus hydrides tend to form chain and ring structures such as cyclopolyphosphine and catenapolyphosphine, respectively. The PH entity has been detected only by spectroscopic analysis, and PH5, P3H, and P18H2 have not been found. 

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