Sodium phosphides

The phosphides are usually made by direct combination of the elements at elevated temperature. The reactive phosphoms is typically red phosphoms, white phosphoms, or phosphoms vapor. Lithium phosphide [12057-29-3] sodium phosphide [12058-85-4] Na P and potassium phosphide [12260-14-9] iron(III) phosphide [26508-33-8] EeP, and diiron phosphide [1310-43-6] Fe2P, are made in this manner. 

Nitrogen and sodium do not react at any temperature under ordinary circumstances, but are reported to form the nitride or azide under the influence of an electric discharge (14,35). Sodium siHcide, NaSi, has been synthesized from the elements (36,37). When heated together, sodium and phosphoms form sodium phosphide, but in the presence of air with ignition sodium phosphate is formed. Sulfur, selenium, and tellurium form the sulfide, selenide, and teUuride, respectively. In vapor phase, sodium forms haHdes with all halogens (14). At room temperature, chlorine and bromine react rapidly with thin films of sodium (38), whereas fluorine and sodium ignite. Molten sodium ignites in chlorine and bums to sodium chloride (see Sodium COMPOUNDS, SODIUM HALIDES). 

Phosphoms trichloride and pentachloride form sodium chloride and sodium phosphide, respectively, in the presence of sodium. Phosphoms oxychloride, POCl, when heated with sodium, explodes. Carbon disulfide reacts violendy, forming sodium sulfide. Sodium amide (sodamide), NaNH2, is formed by the reaction of ammonia gas with Hquid sodium. SoHd sodium reacts only superficially with Hquid sulfur dioxide but molten sodium and gaseous... 

Sodium phosphide (or potassium phosphide) is decomposed by moist air or water, evolving phosphine, which often ignites. 

Phosphine is generated when phosphide salts (i.e., Aluminum phosphide Calcium phosphide Magnesium phosphide Magnesium aluminum phosphide Potassium phosphide Sodium phosphide Stannic phosphide Strontium phosphide Zinc phosphide) come into contact with water. 

The first simple sodium phosphide to be structurally characterized was synthesized in 1995 by Raston and co-workers (68). The complex [Na(PHCy)(pmdeta)]2 crystallizes as dimers with a central planar P2Na2 ring and a trans arrangement of the cyclohexyl substituents across the ring [Na-P = 2.884(8), 2.936(7) A Na-P-Na = 86.2(2)°]. 

LiaP and NaaP have the same structure as NaaAs. Each phosphorus atom is surrounded by 5 alkali metal ions at the comers of a trigonal bipyramid. The lattice contains two types of alkali metal atoms. One sort is surrounded by a trigonal prism of other alkali metal ions, in which the centres of the three vertical faces of the prism are occupied by three phosphorus atoms. The other type of alkali metal ion is surrounded by 4 phosphorus atoms in a distorted tetrahedron. Seven alkali metal ions are found at larger distances. In sodium phosphide the distance between the central phosphorus atom of the trigonal bipyramid and an axial sodium atom is 2.93 A and that between the phosphorus atom and an equatorial sodium atom 2.88 A... 

Sodium reacts with phosphorus on heating to form sodium phosphide, NasP. When ignited with phosphorus in the presence of air, sodium phosphate, NasP04, is obtained. When heated with phosphorus trichloride, sodium reduces the latter compound to elemental phosphorus ... 

On the other hand, heating the metal with phosphorus pentachloride yields sodium phosphide ... 

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. 

At low temperatures ammonia reacts with sodium and red phosphorus to form a reddish-brown, amorphous mass, considered by Hugot1 to be sodium phosphide. With excess of sodium, yellow crystals of the formula Na3P2H3 are formed. They react with water and acids, evolving phosphine ... 

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