Phosphides, properties

Compounds with Sc, Y, lanthanoids and actinoids are of three types. Those with composition ME have the (6-coordinated) NaCl structure, whereas M3E4 (and sometimes M4E3) adopt the body-centred thorium phosphide structure (Th3P4) with 8-coordinated M, and ME2 are like ThAsi in which each Th has 9 As neighbours. Most of these compounds are metallic and those of uranium are magnetically ordered. Full details of the structures and properties of the several hundred other transition metal-Group 15 element compounds fall outside the scope of this treatment, but three particularly important structure types should be mentioned because of their widespread occurrence and relation to other structure types, namely C0AS3,... 

Clark, P.W. and Mulraney, B.J., Synthesis and physical properties of chlo-rodi(o-tolyl)phosphine, lithium di(o-tolyl)phosphide and the diphosphine series (o-tolyl)2P(CH2)nP(o-tolyl) (n = 1-4,6,8), /. Organomet. Chem., 217,51,1981. 

Phosphine produced by the reaction of water on calcium phosphide always contains a quantity of the liquid hydrogen phosphide sufficient to make the gas spontaneously inflammable. Use of this property is made in the Holmes Light used at sea as a distress signal, and also as a marker at torpedo practice. 

The yellow phosphides M3P7 differ from all other phosphides by a remarkable property they sublime congruently dissociative (cf. NHi Cl). In the gas phase only M,g and Pi,g appear, whereas under similar conditions the phosphides M3P11 dissociate into M3P7 and Pi ( ). These compounds can also be obtained as amorphous products by sublimation under suitable conditions. It has been shown that these amorphous products are extraordinarily reactive, therefore they are the most suitable starting materials for the transformations discussed above. 

Figure 9.2 Temperature history of a CPMD simulation of InP indicating the melting of the crystal into a liquid and the quenching of the liquid into an amorphous solid. [Reprinted by per mission from L. J. Lewis, A. De Vita, and R. Car, Structure and Electronic Properties of Amorphous Indium Phosphide from First Principles, Phys. Rev. B 57 (1998), 1594 (Copyright 1994 by the American Physical Society).]...

L. J. Lewis, A. De Vita, and R. Car, Structure and Electronic Properties of Amorphous Indium Phosphide from First Principles, Phys. Rev. B 57 (1998), 1594. 

Elemental composition Ga 69.24%, P 30.76%. Gallium phosphide may be characterized hy its physical and electronic properties. It may also he analyzed hy various x-ray methods. Gallium may he measured hy AA and ICP spectrophotometry following digestion with nitric acid or aqua regia and appropriate dilution (See Gallium). 

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. 

The compounds with larger negative ions, like sulphides, selenides and phosphides, in many respect resemble the interstitial compounds. Like the latter, they often show metallic properties and have variable compositions, but their crystal structures are of quite a different type. 

Arsenic Phosphides.—Black or brown products of indefinite character, to which have been ascribed the formulae AsaP 4 and AsP,5 have been obtained by various methods, such as (1) by heating the elements together,6 (2) by allowing phosphorus to stand in solutions of arsenious acid,7 and (3) by the action of phosphine on arsenic halides.8 The properties of these substances resemble in general those which would be possessed by mixtures of the two elements thus, they burn in air to give the mixed oxides, decompose on heating with vaporisation of first phosphorus and then arsenic, and are oxidised by nitric acid. 

Memming, R. and Schwandt, G., Electrochemical Properties of Gallium Phosphide in Aqueous Solution, Electrochim, Acta, 13, 1299, 1968. 

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