Phosphorus properties

T. D. Parr, Phosphorus—Properties of the Element and S ome of its Compounds, Chemical Engineering Report No. 8, Tennessee Valley Authority, Part XI, U.S. Government Printing Office, Washington, D.C., 1950. 

T. D. Farr, Phosphorus, Properties of the Element and Some of Its Compounds, in Chemical Engineering Report, No. 8, Tennessee Valley Authority, Wilson Dam, Ala., 1950, pp. 39 and 58. 

Quin L D and Verkade J G (eds) 1994 Phosphorus-31 NMR Spectral Properties in Compound Characterization and Structural Analysis (New York VCH)... 

Among the non-metals, nitrogen and chlorine, for example, are gases, but phosphorus, which resembles nitrogen chemically, is a solid, as is iodine which chemically resembles chlorine. Clearly we have to consider the physical and chemical properties of the elements and their compounds if we are to establish a meaningful classification. 

Black phosphorus is formed when white phosphorus is heated under very high pressure (12 000 atmospheres). Black phosphorus has a well-established corrugated sheet structure with each phos phorus atom bonded to three neighbours. The bonding lorces between layers are weak and give rise to flaky crystals which conduct electricity, properties similar to those ol graphite, it is less reactive than either white or red phosphorus. 

This can be extracted from impure phosphine prepared by the action of sodium hydroxide on phosphorus. Unlike hydrazine, it has no basic properties. It is a powerful reducing agent and burns spontaneously in air, this reaction explaining why impure phosphine containing traces of diphosphane ignites spontaneously in air. 

The most important property of phosphorus(V) oxide is its great tendency to react with water, either free or combined. It reacts with ordinary water with great vigour, and much heat is evolved trioxo-phosphoric(V) acid is formed, but the local heating may convert some of this to tetraoxophosphoric(V) acid ... 

Bromine has a lower electron affinity and electrode potential than chlorine but is still a very reactive element. It combines violently with alkali metals and reacts spontaneously with phosphorus, arsenic and antimony. When heated it reacts with many other elements, including gold, but it does not attack platinum, and silver forms a protective film of silver bromide. Because of the strong oxidising properties, bromine, like fluorine and chlorine, tends to form compounds with the electropositive element in a high oxidation state. 

The section on Spectroscopy has been expanded to include ultraviolet-visible spectroscopy, fluorescence, Raman spectroscopy, and mass spectroscopy. Retained sections have been thoroughly revised in particular, the tables on electronic emission and atomic absorption spectroscopy, nuclear magnetic resonance, and infrared spectroscopy. Detection limits are listed for the elements when using flame emission, flame atomic absorption, electrothermal atomic absorption, argon ICP, and flame atomic fluorescence. Nuclear magnetic resonance embraces tables for the nuclear properties of the elements, proton chemical shifts and coupling constants, and similar material for carbon-13, boron-11, nitrogen-15, fluorine-19, silicon-29, and phosphorus-31. 

Phosphorus compounds exhibit an enormous variety of chemical and physical properties as a result of the wide range ia the oxidation states and coordination numbers for the phosphoms atom. The most commonly encountered phosphoms compounds are the oxide, haUde, sulfide, hydride, nitrogen, metal, and organic derivatives, all of which are of iadustrial importance. The hahde, hydride, and metal derivatives, and to a lesser extent the oxides and sulfides, are reactive iatermediates for forming phosphoms bonds with other elements. Phosphoms-containing compounds represented about 6—7% of the compound hstiugs ia Chemical Abstracts as of 1993 (1). 

Table 4. Properties and Electronegativity Differences of Phosphorus—Atom Bonds ...

Properties and Reactions. Phosphorus combines with sulfur to form the binary tetraphosphoms trisulfide [1314-85-8] (phosphoms sesquisulfide), P4S2, (1) tetraphosphoms pentasulfide [12137-70-1] ( )j tetraphosphoms heptasulfide [12037-82-0] P) and phosphoms(V)... 

Some physical properties of the phosphorus sulfohaHdes are summarized in Table 9. 

Table 10. Properties of Allotropic Forms of Phosphorus(V) Oxide...

Properties and Essential Information for S afe Handling and Use of Phosphorus Ouychloride, Chemical Manufacturers Association Chemical Safety Data Sheet SD-26, Washington, D.C., 1948. 

The quality of steels and alloys depend on content at them alloying elements, oxygen, phosphorus, and sulfur. The presence of harmful admixtures worsens properties of materials that show up in formation of cracks, decline of plasticity and malleability. In this connection great value has operations, which allow in this as result to decrease content of solute oxygen, phosphoms, sulfur - desoxidation, desulfuration, dephosphorization. 

Additional n or p-type character may be added to the conduction properties by tire addition of small amounts of impurities such as boron to generate holes in Si and Ge, and phosphorus to generate free electrons. 

Also of interest are salts of melamine (see Chapter 24). In the nylons these can be used with bright colours (unlike red phosphorus) and do not adversely affect electrical properties. They do, however, decompose at about 320°C. Similar materials are very important in giving flame-retardant properties to polyurethane foams. 

Arsenic exists as grey, yellow and black forms of differing physical properties and susceptibilities towards atmospheric oxygen. The general chemistry is similar to that of phosphorus but whereas phosphorus is non-metallic, the common form of arsenic is metallic. Traces of arsenides may be present in metallic residues and drosses these may yield highly toxic arsine, ASH3, with water. 

---