Phosphorus-arsenic compounds

Toxic inorganic substances e.g. Lead, manganese, cadmium, antimony, beryllium, mercury arsenic phosphorus selenium and sulphur compounds, fluorides. 

CHEC-II(1996) comprehensively outlines the most commonly used synthetic approaches applied to these types of bicyclic compounds of phosphorus, arsenic, antimony, and bismuth <1996CHEC-II(8)863>. The six classes of compounds listed in this section have received considerable attention over the review period and as such the principal synthetic methods for these compounds are discussed. Schoth et al. <2000CCR101> have reviewed the use of fluorinated 1,3-diketones, 2-trifluoroacetylphenols, and their derivatives in the synthesis of phosphorus compounds. Included in this review is the use of these reagents for the synthesis of various [3.3.1] nonfused and [3.3.0] fused phosphorus bridgehead bicyclic systems. 

Most of the compounds of arsenic are toxic when in contact with the skin, when inhaled, or when ingested. As with arsenics cousin phosphorus above it in group 15 of the periodic table, care must be taken when using arsenic. The compound arsenic trioxide (As O ), an excellent weed-killer, is also carcinogenic. Copper acetoarsenite, known as Paris green, is used to spray cotton for boll weevils. A poisonous dose of arsenic as small as 60 miUigrams can be detected within the body by using the Marsh test. 

If the action of the enzyme is to produce R—CH2—As(0)(0H)—OR (Section IV,B,2,a), the product will spontaneously hydrolyze, because water can approach the arsenic atom as a fifth ligand in a way it cannot do with the corresponding phosphorus compound. If R OH is a carboxylic or phosphoric acid rather than an alcohol, the hydrolysis is rapid, with a half-life of seconds or less, rather than of about half an... 

Compare the properties of antimony hydride with those of similar compounds of arsenic, phosphorus, and nitrogen (the thermal stability, reducing properties, etc.). 

Sufficient to say that, of all the members of Group 5, the analogies between phosphorus and arsenic are closest. When used as coreactant with arsenic compounds, phosphorus compounds may react interchangeably. The recent preparation of P=As compounds by Escudie et a/.22 relied on this scrambling of arsenic and phosphorus reactants (equation 8). 

Supplement 1951 2085-2358 Diazobenzene, 428. Azoxy Compounds. Azoxybenzene, 621. Nitramines and Nitroso-hydroxylamines., Phenylnitramine, 661. Triazines. Diazoaminobenzene, 687. Phosphorus Compounds. Triphenylphosphine, 759. Arsenic Compounds. Triphenylarsine, 828. Phenylarsonic acid, 868. Antimony Compounds, 891. Bi, Si, Sn, Pb, B, Tl, Mg, Ca, Hg, Na, Pt. 

Light-emitting diodes -arsenic m [ARSENIC AND ARSENIC ALLOYS] (Vol 3) -gallium and indium nitrides in [NITRIDES] (Vol 17) -germaniumm [GERMANIUM AND GERMANIUMCOMPOUNDS] (Vol 12) -phosphorus compounds m [PHOSPHORUS COMPOUNDS] (Vol 18) -use m biosensors [BIOSENSORS] (Vol 4)... 

The common method involves the action of bromine upon a mixture of red phosphorus and water.1-3 The reaction is apt to be violent, and the mixture has been known to explode. The hydrogen bromide is freed from bromine by passing the gas over damp red phosphorus. It is difficult to maintain a steady stream of gas. The product requires drying and is usually contaminated with traces of volatile phosphorus compounds and with small quantities of various arsenic compounds which are derived from impurities in the phosphorus. 

However, the concentration of elemental phosphorus in effluents from industries that produce phosphorus compounds is much lower, compared to industries that do not use chemical conversion processes for producing final products (e.g., WP/F production). White phosphorus also enters water when treated or untreated effluents are released from munitions production facilities that use white phosphorus. Before water recycling measures were implemented at the Pine Bluff Arsenal in Arkansas, the effluent water (phossy water) from the facility contained <53.4 mg/L of white phosphorus (Pearson et al. 1976). 

Different roles in aquatic ecosystems, from acting as nutrients for living organisms (nitrogen and phosphorus compounds) to exerting toxic effects on such organisms (arsenic and mercury). 

The field of phosphorus- or arsenic-bridged compounds is very extensive, especially because of the work of R. G. Hayter and J. Chatt (96). We were able to isolate many /u-phosphido and /x-arsenido metal carbonyls by reacting diphosphines R2PPR2 or the corresponding diarsines (R = alkyl,... 

Classes of organic compounds analysed by this technique include non ionic surfactants, fatty acids, hydrocarbons (all types), organochlorine compounds, organosulphur and phosphorus compounds, substituted aromatic compounds, NT A, EDTA and insecticides and herbicides. Organometallic compounds studied include those of arsenic, lead, germanium, mercury and tin. 

Phosphorus-nitrogen arsenic-chlorine type Alkali metal salt thermionic type Potassium chloride source for phosphorus compounds, rubidium source for nitrogen compounds [397]... 

Salts of the 1 9 arsenic series are more stable than the corresponding phosphorus compounds under most conditions. However, they are slowly converted to colorless salts of lower complexity on long standing with the mother liquor. The 1 9 arsenates are also decomposed by excess sulfuric or hydrochloric acids. 

It is well known that pentacovalent cyclic phosphorus compounds play an important role as intermediates in reactions involving nucleophilic attack on tetracoordinated phosphorus in biological systems. According to this background it appears to us that it is important to prepare the arsenic derivatives, which are more stable than the corresponding phosphorus compounds and allow the study of their conformation. 

Reaction of Cp LnCl with LiPRR yielded [57] Cp2Ln PR3. When lithium cyclohexyl phosphide is used [Cp7YbPhC6Hn] is formed and [Cp2YbPHPh] is obtained with lithium phenylphosphide. These products are not stable in solution and decompose to yield polymeric compounds [CpYbPCgHi 1 ] and [CpYbPPh],. The compound [Cp2Lu(PPh)2Li(tmed) l/2toluene] has been characterized by X-ray analysis [100] with Lu-P distances of 2.782(1) A and 2.813(2) A. The arsenic compound analogous to the phosphorus compound has the same structure [101]. 

The make-up gas must be free of sulfur, arsenic and phosphorus compounds, as well as chlorine and. in general halogenated derivatives which constitute permanent poisons. 

The Function of the Trimethylsilyl Substituent in the Syntheses of Low-valent Phosphorus and Arsenic Containing Compounds... 

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