Preparation of Hydrogen Phosphide

What compounds of phosphorus with hydrogen are known Compare the properties of phosphine (hydrogen phosphide) and ammonia. Write the coordination formulas of the phosphonium ion and hypo-phosphorous acid. 

Preparation of Phosphonium Iodide. Perform the experiment in a medium of dry carbon disulphide. Carbon disulphide is poisonous and readily ignites, its mixture with air is explosive. Work with it requires great care and attention. Distil carbon disulphide in a water bath in the absence of an open flame ) 

After performing the synthesis, treat the remaining carbon disulphide and the ware in which various operations were carried out with an abundant amount of an alkaline potassium permanganate solution. Continue the treatment until the oily drops of the carbon disulphide disappear from the surface of the solution. Perform all the operations in a fume cupboard ) 

To dry carbon disulphide, separate it from the water in which it is stored carbon disulphide is stored under water ) with the aid of a separatory funnel. Pour the carbon disulphide into a bottle with a ground-glass stopper. Spill such an amount of fused calcium chloride into the bottle that its entire bottom is covered with the desiccant, and dry the carbon disulphide at least 24 hours. 

Pour the dry carbon disulphide into a flask for distillation under atmospheric pressure (see Fig. 20) and distil it over the fused calcium chloride, collecting the fraction boiling at 45-46 °C. Heat with hot water in the absence of heating equipment. 

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Iron monophosphide, FeP, results when vaporised phosphorus is passed over diferro phosphide at red heat, until no further increase in weight occurs.3 It has also been prepared by heating phosphorus and iron together at red heat,4 and also by the action of hydrogen phosphide upon ferric chloride,5 ferrous sulphide,6 or ferrous chloride 7 at red heat. 

In addition to the foregoing, several other phosphides have been described, but the evidence in favour of these being separate chemical entities is not so convincing.10 Hose believed that he had prepared triferro tetraphosphide, Fe3P4, by the action of hydrogen phosphide upon pyrites —... 

By pyrolysis of a mixture of hydrogen phosphide and silicon hydride, it was Fritz [1] who first succeeded in the preparation of a simple compound with an Si-P bond. About forty years ago, neither the author nor his colleagues anticipated that the silyl phosphane H3S1-PH2 would become the parent compound of a widely used class of starting materials. On the contrary, silylphosphanes remained peculiarities imtil a convenient synthesis of the tris(trimethylsilyl) derivative (Me3Si)3P had been developed [2]. 

Semiconductors. Phosphine is commonly used in the electronics industry as an -type dopant for siUcon semiconductors (6), and to a lesser extent for the preparation of gaUium—indium—phosphide devices (7). For these end uses, high purity, electronic-grade phosphine is required normally >99.999% pure. The main impurities that occur in phosphine manufactured by the acid process are nitrogen [7727-37-9] hydrogen [1333-74-0] arsine [7784-42-17, carbon dioxide [124-38-9], oxygen [7782-44-7], methane [74-82-8], carbon monoxide [630-08-0], and water [7732-42-1]. Phosphine is purified by distillation under pressure to reduce the level of these compounds to <1 ppm by volume. The final product is sold as CYPURE (Cytec Canada Inc.) phosphine. 

Some phosphides, such as titanium phosphide [12037-65-9] TiP, can be prepared bypassing phosphine over the metal or its haUde. Reaction of phosphine with heavy metal salt solutions often yields phosphines that may contain unsubstituted hydrogens. Phosphides may also be prepared by reducing phosphoms-containing salts with hydrogen, carbon, etc, at high temperatures, the main example of which is the by-product formation of ferrophosphoms in the electric furnace process for elemental phosphoms. Phosphoms-rich phosphides such as vanadium diphosphide [12037-77-3] may be converted to lower phosphides, eg, vanadium phosphide [12066-53-4] by thermal treatment. 

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. 

Diphosphine is formed by the hydrolysis of calcium phosphide 22.424,425, 428,429) gjgQ jy hydrolysis of other phosphides when these contain P—P linkages. Thus, for example, it is reported that the phosphine obtained by the hydrolysis of aluminium phosphide, which has been prepared from the elements with phosphorus in excess, is spontaneously inflammable. This is caused by the diphosphine formed at the same time. When the aluminium phosphide is prepared using stoichiometric or even excess amounts of aluminium, the formation of diphosphine is not observed on hydrolysis. The diphosphine, formed in large quantities by the hydrolysis of calcium phosphide, can be separated from the phosphine and hydrogen evolved simultaneously by cool-... 

Phosphates have been formed by slow hydrolysis of trialkyl phosphates, hydrogen phosphate ions, or metaphosphoric acid, which liberate phosphate ions (see p. 46 in Ref. 31). This may be of interest as a precursor for the preparation of phosphide semiconductors. 

The formation and preparation of phosphine.—The modes of preparation are sometimes divided into (i) those which furnish the spontaneously inflammable gas, i.e. the gas inflames when it comes in contact with air at ordinary temp, and press, and (ii) those which furnish the non-spontaneously inflammable gas which takes fire only at an elevated temp, or under a reduced press. Since these divergent qualities are determined by the presence or absence of traces of hydrogen hemi-phosphide, (PH2)2, and since this impurity may or may not be removed from the gas by suitable treatment, there are no essential differences in the modes of preparation of the spontaneously accendible and non-accendible forms of the gas. T. Graham 4 made a special study of the conversion of the spontaneously inflammable gas into the non-accendible form. He said ... 

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