Salt of phosphorus

Graham similarly adopted the new notation "in such cases where it may be expedient," for example, in expressing his results for the acids and salts of phosphorus.67 The British Association for the Advancement of Science constituted a committee that reported in 1835 that a majority of the sixteen members approved the new "continental" notation, with the proviso that "it is desirable not to deviate. . . from algebraic usage except so far as convenience requires."68... 

A theoretical analysis has been made of che dual reactivity of salts of phosphorus(V) thio acids. In alkylation reactions, the variation in products brought about by changes in alkylating agent can be illustrated by reference to the diethyl phosphorothioate anion for this, triethoxonium fluoroborate yields almost exclusively the S-ethyl derivative, alkyl tosylates in HMPT react to yield both S and 0-alkyl derivatives, and chlorotrimethylsilane reacts only at oxygen. S-alkylation occurs almost exclusively in non-polar or weakly polar solvents, but also in ethanol. In HMPT the S 0 ratio was shown to depend on the substituents attached to phosphorus. It was suggested that 0-alkylation occurs when the free ion is available, whereas reaction at sulphur occurs when the oxygen end of the 0-P-S triad is preferentially solvated and so shielded. 

Nanostructured hydroxyapatite Caio(P04)g(OH)2 (HAP) was synthesized using aqueous solutions of the corresponding salts of phosphorus ((NH4)2HP04) and nitric (Ca(N03) 2H20) acids (Vysotskaja et al. 2002) ... 

Fig. 2. Principal absorption regions in salts of phosphorus oxy-acids [ ]. rectangles denote absorption in hydrated salts only.

Spectra-correlation charts for salts of phosphorus oxy-acids (2-16 n) [ ], for phosphorus compounds (2-26 l) [ ], for aryl phosphoric acids (2-16 n) and for organosilicon compounds (2-16 n)... 

Battley [58] pointed out that ash-free dry weights lead to a 5 to 6 % smaller amount of CHON-containing cell mass than determined by means of the total cellular composition. This is due to the fact that the salts of phosphorus and sulfur add a higher weight to the ash than the elements contribute to the weight of the cellular fabric. Such differences have to be taken into account when comparing caloric values of different authors. 

On concentrating the solution, a solid of formula As40jq. SH O (which may be composed by hydrated arsenic(V) acid) is obtained, and this, on fairly prolonged heating to 800 K, loses water and leaves arsenic(V) oxide. No compounds corresponding to the other acids of phosphorus are formed, but salts are known. 

The crude acetonitrile contains as impurity chiefly acetic acid, arising from the action of phosphoric acid on the acetamide. Therefore add to the nitrile about half its volume of water, and then add powdered dry potassium carbonate until the well-shaken mixture is saturated. The potassium carbonate neutralises any acetic acid present, and at the same time salts out the otherwise water-soluble nitrile as a separate upper layer. Allow to stand for 20 minutes with further occasional shaking. Now decant the mixed liquids into a separating-funnel, run off the lower carbonate layer as completely as possible, and then pour off the acetonitrile into a 25 ml, distilling-flask into which about 3-4 g. of phosphorus pentoxide have been placed immediately before. Fit a thermometer and water-condenser to the flask and distil the acetonitrile slowly, collecting the fraction of b.p. 79-82°. Yield 9 5 g. (12 ml.). 

B) Sulphonamides. Mix 0 5 g. of the sulphonic acid or its alkali salt with 15 g. of phosphorus pentachloride, and heat under reflux in a silicone- or oil-bath at 150° for 30 minutes then allow it to cool. 

Very pure acid chlorides may be obtained by reaction between the anhydrous sodium salt of the acid and phosphorus oxychloride, for example ... 

Sulphonamides. Mix together 1 0 g. of the dry acid or 1 - 2 g. of the anhydrous salt with 2 5 g. of phosphorus pentachloride f and heat under a reflux condenser in an oil bath at 150° for 30 minutes. Cool the mixture, add 20 ml. of dry benzene, warm on a steam bath and stir the solid mass well to extract the sulphonyl chloride filter. Add the benzene solution slowly and with stirring to 10 ml. of concentrated ammonia solution. If the sulphonamide precipitates, separate it by filtration if no solid is obtained, evaporate the benzene on a steam bath. Wash the sulphonamide with a little cold water, and recrystallise from water, aqueous ethanol or ethanol to constant m.p. 

As the most significant point sources of phosphorus are those from sewage treatment works (STW), control of phosphorus loading is most readily achieved either by precipitation of phosphorus with iron salts (iron(lll) sulfate or iron(lll) chloride) or by biological removal. The latter can only effectively be achieved in STWs using activated sludge and there have been many descriptions of this technique. ... 

Most lakes affected by eutrophication will also have significant amounts of phosphorus in their sediments, which can be recycled into the water column (Section 4). The control of this source can be achieved by treating the sediments with iron salts or calcite to bind the phosphorus more tightly into the sediments. These methods have been used to some effect, but consideration has to be given to the quality of the materials used and whether or not the lake can become de-oxygenated in the summer. In the latter case this can be overcome by artificial de-stratification. 

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. 

Bromine (7 ml) is added dropwise to a mixture of white sand (14 g) and red phosphorus (3 g, dried at 165° under vacuum) moistened with 5 ml of deuterium oxide. The apparatus is fitted with an exit tube to allow the liberated deuteriobromic acid to pass through two U-tubes and into a receiving flask. The first trap contains glass beads and is cooled in an ice-salt slurry. The second contains glass beads and red phosphorus moistened with deuterium oxide. The deuterium bromide gas is collected in the appropriate solvent at ice bath temperature. A small amount of phosphorus pentoxide should be added to remove any deuterium oxide if anhydrous reagent is required. 

Trifluoromethanesulfonic (triflic) anhydride is commercially available or can be prepared easily by the reaction of triflic acid with phosphorus pentoxide [66] This moderately hygroscopic colorless liquid is a useful reagent for the preparation of various organic derivatives of triflic acid A large variety of organic ionic triflates can be prepared from triflic anhydride A recent example is the preparation of unusual oxo-bridged dicatiomc salts of different types [SS, 89, 90, 91, 92, 93] (equations 38-44) Stabilized dication ether salts of the Huckel aromatic system and some other systems (equations 38 and 39) can be prepared in one step by the... 

Phosphorus oxychloride and the sodium salt of the acid can. ilso lie used. 

Oxoacids of phosphorus and their salts Table 12.10 Factors affecting the rate of polyphosphate degradation... 

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