Phosphorus, elemental reactions with

White Phosphorus Oxidation. Emission of green light from the oxidation of elemental white phosphoms in moist air is one of the oldest recorded examples of chemiluminescence. Although the chemiluminescence is normally observed from sotid phosphoms, the reaction actually occurs primarily just above the surface with gas-phase phosphoms vapor. The reaction mechanism is not known, but careful spectral analyses of the reaction with water and deuterium oxide vapors indicate that the primary emitting species in the visible spectmm are excited states of (PO)2 and HPO or DPO. Ultraviolet emission from excited PO is also detected (196). 

Few industrial uses have so far been found for phosphides. Ferrophosphorus is produced on a large scale as a byproduct of P4 manufacture, and its uses have been noted (p. 480). Phosphorus is also much used as an alloying element in iron and steel, and for improving the workability of Cu. Group 3 monophosphides are valuable semiconductors (p. 255) and Ca3P2 is an important ingredient in some navy sea-flares since its reaction with water releases spontaneously flammable... 

Zinc and cadmium tarnish quickly in moist air and combine with oxygen, sulfur, phosphorus and the halogens on being heated. Mercury also reacts with these elements, except phosphorus and its reaction with oxygen was of considerable practical importance in the early work of J. Priestley and A. L. Lavoisier on oxygen (p. 601). The reaction only becomes appreciable at temperatures of about 350° C, but above about 400°C HgO decomposes back into the elements. 

The ionization energy of the sulfur atom shows that it is even more reluctant than phosphorus to lose electrons. The common compounds of sulfur are the sulfides, which may be formed by reactions of elemental sulfur with a large number of metals. Typical reactions are... 

This reaction is an example of a hydrolysis reaction, a reaction with water in which new element-oxygen bonds are formed. Another example is the reaction ot PC15 (phosphorus oxidation state +5) with water to produce phosphoric acid, H3P04 (also phosphorus oxidation state - -5) ... 

The only structurally characterized derivative of a trisimido organophos-phonate anion is the spirocyclic tellurium(IV) complex (19), which is obtained from the interesting redox reaction between PhPCl2 and [Li2Te(N Bu)3 ] 2 [27]. The phosphorus(V)-centered ligands are generated by imide transfer from tellurium to the phosphorus(III) atoms with concomitant reduction of one-half of the tellurium in the Te(IV) reagent to elemental tellurium [27]. 

With phosphorus trichloride, a rather complex reaction results partly in the formation of [PhaP N uPPha PPhCl]+ Cl. The reactivity of the phosphorus(iii) atom is also demonstrated by its ability to desulphurize thiophosphoryl chloride, and its ready reactions with Group VI elements, diborane, and carbon disulphide ... 

Another general method for converting alcohols to halides involves reactions with halides of certain nonmetallic elements. Thionyl chloride, phosphorus trichloride, and phosphorus tribromide are the most common examples of this group of reagents. These reagents are suitable for alcohols that are neither acid sensitive nor prone to structural rearrangement. The reaction of alcohols with thionyl chloride initially results in the formation of a chlorosulfite ester. There are two mechanisms by which the chlorosulfite can be converted to a chloride. In aprotic nucleophilic solvents, such as dioxane, solvent participation can lead to overall retention of configuration.7... 

The last reaction is the most favored of these three. The actual occurrence of the reactions with elemental phosphorus or phosphorous trichloride as products has been explained to be due to kinetic reasons. The thorium present in the ore volatilizes in the form of thorium tetrachloride (ThCl4) vapor other metallic impurities such as iron, chromium, aluminum, and titanium also form chlorides and vaporize. The product obtained after chlorination at 900 °C is virtually free from thorium chloride and phosphorous compounds, and also from the metals iron, aluminum, chromium, and titanium. 

Both XIV and XV are highly reactive and neither can be isolated from the reaction mixture in the absence of F,t2NH however, upon reaction with elemental sulfur, conversion to the phosphorus sulfide analogs (XVI and XVII) occurs. The latter are crystalline solids stable indefinitely at 25°C in the absence of Et2NH. 

Two approaches have been used in the synthesis of these types of compounds. Small boron-phosphorus ring compounds can serve as building blocks, and addition and elimination reactions with other main group elements can then extend the cage structure (see Schemes 23 and 24, Section 12.12.6.4.5). Alternatively, an unsaturated carbenoid fragment can be added to the bicyclic fragment as illustrated in Scheme 31 <1998IC490>. 

Phosphorus is one of the most important elements in soil chemistry because it is involved in numerous reactions with many different components. In addition to the species described earlier, phosphate will also form species with uranium, arsenic, and zinc. It also reacts with organic matter and with humic and fulvic acids to form environmentally important species [33-37],... 

The starting diol was transformed into the dibromide by elemental bromine with triphenyl phosphine adduct which undergoes the Arbuzov-Michaelis reaction under somewhat drastic conditions at 150 °C (step a). Catalytic removal of the benzyl group was performed by a Pd/C catalyst (step b) and the alcohol formed was allowed to react with dichloropurine in the presence of triphenylphosphine and diethylazodicarboxylate (Mit-sunobu reaction) (step c). Finally the desired product was obtained by reaction with methylamine (step d) and the removal of ethyl groups at the phosphorus centre was performed by transilylation using trimethyliodosilane (step e). 

Potassium dihydrogenphosphide dissolved in dimethylformamide, is probably dissociated into ions. This is confirmed by the equivalent conductance, the value of 77.0 f2 cm mol was found for a 8 10 mol/cm solution. The PH2 ion is a strong nucleophilic reagent. The study of its chemical behaviour towards oxygen, sulphur and white phosphorus has produced, to date, no conclusive results. The reaction with the latter element results in the formation of an amorphous red-brown substance of composition KPsH2 which is soluble in dimethylformamide. ... 

Most of the world production of phosphates goes into fertilizer, but some is used as detergent builders (Section 7.7). In toothpastes, calcium pyrophosphate has proved effective as a mild abrasive in eliminating tartar, while Na2[FP03], made by reaction of NaF with cyclic sodium metaphosphates (NaP03), is widely used as a fluoridating agent to suppress dental caries (Section 12.3). A minor amount of rock phosphate is used to make elemental phosphorus by reduction with coke in the presence of silica in the electric furnace (see Section 17.7) ... 

---