Phosphorus compounds of, oxidation

Other oxides of phosphorus are less well characterized though the suboxide PO and the peroxide P2O6 seem to be definite compounds. PO was obtained as a brown cathodic deposit when a saturated solution of Et3NHCl in anhydrous POCI3 was electrolysed between Pt electrodes at 0°. Alternatively it can be made by the slow reaction of POBrs with Mg in Et20 under reflux ... 

The cyclopolyphosphines that were used to prepare the carbene-phosphinidene complexes described earlier were formed by the reduction of higher oxidation state phosphorus compounds, typically di-chlorophosphines, RPC12 (47-49). However, in some cases a separate reduction step is not necessary and it is possible to prepare the car-bene-phosphinidene complex (74) directly by reaction of a stable nucleophilic carbene with RPC12 (44). 

Some reactions of 2,2 -bipyridine /V-oxides have been reported. The l,T-dioxide is nitrated readily to 4,4 -dinitro-2,2 -bipyridine 1,T-dioxide. ° ° °" 2,2 -Bipyridine 1-oxide is also nitrated in the 4 position. The nitro groups in 4,4 -dinitro-2,2 -bipyridine l,T-dioxide are reactive, being replaced by chlorine with concentrated hydrochloric acid," by bromine with acetyl bromide, by hydroxyl with dilute sulfuric acid, and by alkoxy groups with sodium alkoxides. Some of the dialkoxy derivatives are useful catalysts for the oxidation of aromatic compounds. The dinitro dioxide is deoxygenated to 4,4 -dinitro-2,2 -bipyridine with phosphorus trichloride in chloroform, and other substituted l,T-dioxides behave similarly, but with phosphorus trichloride alone, 4,4 -dichloro-2,2 -bipyridine results. The dinitro dioxide is reduced by iron powder in acetic acid to 4,4 -diamino-2,2 -bipyridine, whereas 4,4 -dichloro-2,2 -bipyridine l,T-dioxide is converted to its 4,4 -diamino analogs with amines. Related reactions have been described. ... 

Remarkable enhancements of the unimolecular c-t isomerization of c-S with p-MeO and oxidation of S with -MeO are explained by charge-spin separation in such S Unimolecular c-t isomerization of such c-S proceeds with a chain mechanism, while regioselective oxidation occurs in such S because of the spin localization. Cycloreversion of t,c,t-TPCB occurs to give a a-St 2, while the photochemical cycloreversion of TPCB and t,t,t-TPCB gives Tr-St 2 and t-St /t-St pair, respectively. Radical cations of phosphorus compounds (9 and 10 form intramolecular rr-dimer between two Nps from which Np 2 forms. Formation of intermolecular a-dimer of aromatic acetylene (11 - and 12 -) and intramolecular dimer of 13 and diarylmethanoT was observed, and the n = 3 rule is not effective for intramolecular dimer -. 

Sir Edward (T. E.) Thorpe, 1845-1925. English chemist famous for his research on the specific volumes of liquids in relation to their chemical constitution, and for his work on the oxides of phosphorus and the compounds of vanadium done in collaboration with Sir Henry Roscoe. Author of excellent textbooks of chemistry and of biographies and essays in historical chemistry. 

Binary oxides of phosphorus, arsenic and antimony are polycyclic compounds, e.g. E4O6 (E = P, As, Sb), with an adamantane-like structure. Monocyclic... 

Anodic oxidation of organosilicon compounds bearing heteroatoms and its synthetic applications have been studied intensively. The oxidation potentials of organosilicon compounds bearing nitrogen, sulfur and phosphorus atoms at the a-, ji- and /-positions were shown in Table 512-21-23. it should be noted that the silyl group a to the heteroatom decreases appreciably the oxidation potential. 

The reaction was also carried out on the laboratory scale by Bayer 182) (use of special electrolytes and collidine as an auxiliary base), Fuso 183> (use of phosphorus compounds as conductive salts) and UOPl84) (use of alcoholates as electrolytes). Under comparable conditions, p-cresol cannot be oxidized to the corresponding p-hydroxy-benzaldehyde derivatives. If the phenolic hydroxyl group is protected, it is also possible to obtain p-hydroxybenzaldehyde derivatives. 

The compound P4O10, known as phosphorus pentoxide, is the most common and most important oxide of phosphorus. This compound exists in three modifications. When phosphorus burns in air and condenses rapidly from the... 

Oxidation of phosphorus by oxygen, for example, may yield three distinct oxides (P4O, P4O10, and PjO ), whereas oxidations by sulfur may yield one or more of three possible sulfides (P4S, P4S7, and Preaction between phosphorus and oxygen or sulfur depend not only on the atomic ratios of the components used, but also on reaction conditions.) Certain of the more important binary halides, oxides, and sulfides of this group are described in later sections of this chapter, but the list is only partial. 

Related problems must be considered in individual products. Bromine, chlorine, and antimony add to the smoke of a fire, while phosphorus and water do not, and some metal oxides can actually reduce it. Toxicity of combustion gases is a major concern but the main problem is that oxidation of carbon compounds in an enclosed space—indoors— produces carbon monoxide, no matter whether the carbon compounds are wood or plastics. Other problems include the cost of flame-retardants, difficulties in processing, and loss of mechanical or thermal properties. 

These compounds are soluble in carbon disulphide, from which they may be obtained as orange or yellow crystals. They are only slightly soluble in other organic solvents such as benzene, chloroform, etc. They can be burnt in air, giving oxides of phosphorus, sulphur and iodine. They are decomposed by warm water or moist air, giving first phosphoric and hydriodie acids, then phosphoric acid and hydrogen sulphide.4... 

The acid which is produced finally by the oxidation of phosphorus in the presence of sufficient water and after heating has probably the constitutional formula OP(OH)s (see p. 59). The term ortho, in accordance with Graham s description, was applied to ordinary phosphoric acid. Later, on the hypothesis of the quinquevalent nature of phosphorus, it was considered that the hypothetical acid P(OH)5 would, strictly speaking, be the ortho acid. However, the present theories of valency do not indicate the possible existence of such an acid, but rather that OP(OH)3 should be the most highly hydroxylated compound. 

The formula of an oxide of phosphorus is P2O5. Make an educated guess as to which one of the following formulas represents a real compound S2O5 Ga205 AS2O5... 

The oxidation of carbon compounds is treated only very briefly and avoids the reactions of the carbon monoxide oxidation. Although kinetic studies of the phosphorus oxidation have not until now yielded any rate coeflScients, we have nonetheless included a survey of the work done because it is obvious that once a few rate coelficients have been unequivocally determined, the relationships discussed will then yield many other quantitative results. 

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