Phosphorus atmosphere

A solution of o-bromothioanisole (77 g) in 400 ml of ether is treated with an equimolar quantity (250 ml of a 1.5iV solution) of n-butyllithium in hexane over 2 hr at 0° under a nitrogen atmosphere. Phosphorus trichloride (17.5 g in 250 ml of ether) is added dropwise via a pressure-equalizing dropping funnel over 3 hr, and then the reaction mixture is hydrolyzed with 250 ml of 0.2N hydrochloric acid. The resultant white precipitate is washed thoroughly with water, ethanol, and ether and then dried (yield 45 g, 89 %). The compound is recrystallized from n-butanol. Anal. Calcd. for C21H21PS3 C, 62.97 H, 5.28 S, 24.02. Found C, 62.9 H, 5.43 S. 24.0. 

Pb(P03)2 and Pb3(P04)2. In the exterior 20% of the washcoat (i.e. toward the external washcoat surface), however, the phosphorus concentration was disproportionately greater than the lead concentration. At the external surface of the washcoat, the phosphorus concentration was -— 180-fold that of lead. Under the conditions of the exhaust gas atmosphere, phosphorus could be present on the catalyst only in the form of stable phosphate compounds. The high phosphorus concentration in the external surface region of the washcoat indicated that chemical interaction between phosphorus and the washcoat material had occurred to form hydrothermally stable phosphates such as aluminum phosphates, e.g. A1(P03)3 and A1P04. X-ray analysis of this catalyst failed to confirm the presence of crystalline aluminum phosphates. It is therefore con-... 

In some cases atmospheric phosphorus inputs can be important contributions to the overall phosphorus balance in both terrestrial and aquatic ecosystems, notably where dust deposition provides phosphorus to highly oligotrophia lakes (Gibson etal, 1995 Newman, 1995). Further, modelling studies indicate that the deposition of phosphorus in dust can have a marked influence on longterm ecosystem development, at least in tropical forests (see Parton et al.. Chapter 15, this volume). However, organic phosphorus is rarely quantified in precipitation, and little published data exists. 

Earths crust (including oceans and atmosphere) Phosphorus P Magnesium Mg Sodium Na (from natrium)... 

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. 

Method 2. Place 90 g. of sodium benzenesulphonate (Section IV,29) (previously dried at 130-140° for 3 hours) and 50 g. of powdered phosphorus pentachloride (1) in a 500 ml. round-bottomed flask furnished with a reflux condenser heat the mixture in an oil bath at 170-180° for 12-15 hours. Every 3 hours remove the flask from the oil bath, allow to cool for 15-20 minutes, stopper and shake thoroughly until the mass becomes pasty. At the end of the heating period, allow the reaction mixture to cool. Pour on to 1 kilo of crushed ice. Extract the crude benzenesulphonyl chloride with 150 ml. of carbon tetrachloride and the aqueous layer with 75 ml. of the same solvent. Remove the solvent under atmospheric pressure and proceed as in Method 1. The yield is about 170 g., but depends upon the purity of the original sodium benzenesulphonate. 

One of the things that environmental scientists do IS to keep track of important elements in the biosphere—in what form do these ele ments normally occur to what are they transformed and how are they returned to their normal state Careful studies have given clear although compli cated pictures of the nitrogen cycle the sulfur cy cle and the phosphorus cycle for example The carbon cycle begins and ends with atmospheric carbon dioxide It can be represented in an abbrevi ated form as... 

Phosphorus pentacfaloride [10026-13-8] M 208.2, m 179-180 (sublimes). Sublimed at 160-170° in an atmosphere of chlorine. The excess chlorine was then displaced by dry N2 gas. All subsequent manipulations were performed in a dry-box [Downs and Johnson J Am Chem Soc 77 2098 1955]. Fumes in moist air. HARMFUL VAPOURS. 

Phosphorus exists as white and red phosphorus. The former allotrope may be preserved in the dark at low temperatures but otherwise reverts to the more stable red form. The white form is a waxy, translucent, crystalline, highly-toxic solid subliming at room temperature and inflaming in air at 35°C, so it is handled under water. The red form is a reddish violet crystalline solid which vaporizes if heated at atmospheric pressure and condenses to give white phosphorus. The red form ignites in air at 260°C. Both are insoluble in water, and white phosphorus can be stored beneath it. Phosphorus forms a host of compounds such as phosphine, tri- and penta-halides, tri-, tetra- and penta-oxides, oxyacids including hypophosphorous, orthophosphorous and orthophosphoric acids. 

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. 

Nitrogen makes up 78 % of the atmosphere, hence, it is readily available. Ammonia is produced by fixing of atmospheric nitrogen with hydrogen. Mineral sources of phosphorus and potassium are converted to a suitable form for fertilizer. These three elements have other use than fertilizer they are used and interact with other facets of the chemical industry, making a highly complex picture. A schematic of the interactions is presented in Figure 7.2-1. 

Phosphorus also occurs in all living things and the phosphate cycle, including the massive use of phosphatic fertilizers, is of great current interest.O 20) -pj.jg movement of phosphorus through the environment differs from that of the other non-metals essential to life (H, C, N, O and S) because it has no volatile compounds that can circulate via the atmosphere. Instead, it circulates via two rapid biological... 

Phosphorus (like C and S) exists in many allotropic modifications which reflect the variety of ways of achieving catenation. At least five crystalline polymorphs are known and there are also several amorphous or vitreous forms (see Fig. 12.3). All forms, however, melt to give the same liquid which consists of symmetrical P4 tetrahedral molecules, P-P 225 pm. The same molecular form exists in the gas phase (P-P 221pm), but at high temperatures (above 800°C) and low pressures P4 is in equilibrium with the diatomic form P=P (189.5 pm). At atmospheric pressure, dissociation of P4 into 2P2 reaches 50% at 1800°C and dissociation of P2 into 2P reaches 50% at 2800°. 

The mixture was then hydrogenated at just above atmospheric pressure for 1 A hours and filtered through a Dicalite bed. The clear filtrate was evaporated at low temperature and pressure, and the residue dried in vacuo over phosphorus pentoxide, to give 1.64 g of the salt of Q-(3-thienyl)methylpenici lin as a white solid. 

One disadvantage of tough pitch coppers is the embrittlement that is liable to occur when they are heated in atmospheres containing hydrogen. For many purposes, therefore, and particularly where fabrication is involved, deoxidised coppers are preferred. The usual deoxidising agent is phosphorus, and specifications require residual phosphorus contents of between... 

Thompson and Tracy carried out tests in a moist ammoniacal atmosphere on stressed binary copper alloys containing zinc, phosphorus, arsenic, antimony, silicon, nickel or aluminium. All these elements gave alloys susceptible to stress corrosion. In the case of zinc the breaking time decreased steadily with increase of zinc content, but with most of the other elements there was a minimum in the curve of content of alloying elements against breaking time. In tests carried out at almost 70MN/m these minima occurred with about 0-2% P, 0-2% As, 1% Si, 5% Ni and 1% Al. In most cases cracks were intercrystalline. 

Triethylamine was dried by distillation from phosphorus pentoxide at atmospheric pressure. The checkers used reagent-grade material available from Eastman Organic Chemicals. 

Commercial triethylamine (obtained from Eastman Organic Chemicals), was distilled from phosphorus pentoxide, and the pure amine (b.p. 86-90°) was stored under a nitrogen atmosphere. Since the presence of even a small excess of triethylamine is deleterious in these reactions, the quantities of this amine used should be measured by weight rather than volume. 

Previously, trifluorosilyl groups have been bound to phosphorus (40) and silicon via the SiF (g), fluorine-bond insertion-mechanism (41). The new compound HgCSiFs) is readily hydrolyzed, but it can be stored for long periods of time in an inert atmosphere. It is a volatile, white solid that is stable up to at least 80°C. The preparation of bis(trifluoro-silyDmercury, of course, raises the possibility of (a) synthesis of the complete series of trifluorosilyl, "silametallic compounds, as had previously been done for bis(trifluoromethyl)mercury by using conventional syntheses, and (b) transfer reactions similar to those in Section II, as well as (c) further exploration of the metal-vapor approach. The compound Hg(SiF.,)j appears also to be a convenient source of difluoro-silane upon thermal decomposition, analogous to bis(trifluoromethyl)-mercury ... 

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