Oxidation compounds

Cortisol-Cortisone Conversion. Under normal conditions, this equilibrium slightly favors the oxidized compound. Similarly, the conversion of corticosterone to 11-deoxycorticosterone is also mediated by the liP-hydroxysteroid dehydrogenase enzyme system and requites NAD(P) /NAD(P)H. This conversion is especially important both in the protection of the human fetus from excessive glucocorticoid exposure, and in the protection of distal nephron mineral ocorticoid receptors from glucocorticoid exposure (14). The impairment of this conversion is thought to result in hypertension associated with renal insufficiency (15). 

The term ferrite is commonly used generically to describe a class of magnetic oxide compounds which contain iron oxide as a principal component. In metallurgy (qv), however, the term ferrite is often used as a metaHographic indication of the a-iron crystalline phase. 

The cellulose dissolving potential of the amine oxide family was first realized (79) in 1939, but it was not until 1969 that Eastman Kodak described the use of cycHc mono(/V-methy1amine-/V-oxide) compounds, eg, /V-methylmorpho1ine-/V-oxide [7529-22-8] (NMMO), as a solvent size for strengthening paper (80) by partially dissolving the cellulose fibers. 

Chlorine and Bromine Oxidizing Compounds. The organo chlorine compounds shown in Table 6 share chemistry with inorganic compounds, such as chlorine/77< 2-3 (9-j5y and sodium hypochlorite/7 )< /-j5 2-5 7. The fundamental action of chlorine compounds involves hydrolysis to hypochlorous acid (see Cm ORiNE oxygen acids and salts). 

Measurement and specification of nitrates or other nitrogen oxide compounds in sulfuric acid is a complex subject. The difficulty occurs because nitrogen oxides are usually present both as nitrous and nitric compounds, predominantiy in the nitrous form. Hence, analytical procedures specific for nitrates only do not give a complete analysis. 

A procedure to measure both types of nitrogen oxide compounds at the same time involves development of a pink color by mixing FeSO with sulfuric acid, followed by measurement or comparison of color intensity. This general type of procedure and the possible alternatives ate discussed in References 148—150. 

Inorganic Titanates. Titanium forms a series of mixed oxide compounds with other metals. Only in one of these, Ba2Ti04, ate there discrete TiOJ ions (99). Compounds of the general formula M" 2Ti02 or M " Ti02 are known as metatitanates those having AU TiO and are called... 

Zirconium occurs naturally as a siUcate in zircon [1490-68-2] the oxide baddeleyite [12036-23-6] and in other oxide compounds. Zircon is an almost ubiquitous mineral, occurring ia granular limestone, gneiss, syenite, granite, sandstone, and many other minerals, albeit in small proportion, so that zircon is widely distributed in the earth s cmst. The average concentration of zirconium ia the earth s cmst is estimated at 220 ppm, about the same abundance as barium (250 ppm) and chromium (200 ppm) (2). 

It follows, then, that oxidizing substances, such as dissolved air, may accelerate the corrosion of one class of materials and retard the corrosion of another class. In the latter case, the behavior of the material usually represents a balance between the power of oxidizing compounds to preserve a protective film and their tendency to accelerate corrosion when the agencies responsible for protective-film breakdown are able to destroy the films. 

Figure 4 Local microstruetures and experimental solid state NMR spectra in crystalline vanadium oxide compounds.

The amount of HOCl plus OCl in wastewater is referred to as the free available chlorine. Chlorine is a very active oxidizing agent and is therefore highly reactive with readily oxidized compounds such as ammonia. Chlorine readily reacts with ammonia in water to form chloramines. 

Tantalum and niobium are added, in the form of carbides, to cemented carbide compositions used in the production of cutting tools. Pure oxides are widely used in the optical industiy as additives and deposits, and in organic synthesis processes as catalysts and promoters [12, 13]. Binary and more complex oxide compounds based on tantalum and niobium form a huge family of ferroelectric materials that have high Curie temperatures, high dielectric permittivity, and piezoelectric, pyroelectric and non-linear optical properties [14-17]. Compounds of this class are used in the production of energy transformers, quantum electronics, piezoelectrics, acoustics, and so on. Two of... 

The physical and chemical properties of any material are closely related to the type of its chemical bonds. Oxygen atoms form partially covalent bonds with metals that account for the unique thermal stability of oxide compounds and for typically high temperatures of electric and magnetic structure ordering, high refractive indexes, but also for relatively narrow spectral ranges of transparency. 

One of the most important parameters that defines the structure and stability of inorganic crystals is their stoichiometry - the quantitative relationship between the anions and the cations [134]. Oxygen and fluorine ions, O2 and F, have very similar ionic radii of 1.36 and 1.33 A, respectively. The steric similarity enables isomorphic substitution of oxygen and fluorine ions in the anionic sub-lattice as well as the combination of complex fluoride, oxyfluoride and some oxide compounds in the same system. On the other hand, tantalum or niobium, which are the central atoms in the fluoride and oxyfluoride complexes, have identical ionic radii equal to 0.66 A. Several other cations of transition metals are also sterically similar or even identical to tantalum and niobium, which allows for certain isomorphic substitutions in the cation sublattice. 

The formation of oxide compounds as a result of the thermal treatment of oxyfluorides is due to high temperature hydrolysis and reduction-oxidation processes. 

In other cases, if the fluorination process leads to cardinal changes in the crystal structure of the initial oxide compounds, new compounds with polar structures can be obtained. A demonstrative example of such materials are compounds that belongs to the system Na5(W3 xNbx)09..xF5+x and that have chiolite-type structures, when neither pure fluoride nor oxide display any ferroelectric properties [393 - 395]. 

The processing of tantalum and niobium begins with the fluorination of the raw material, which always consists of complex oxide compounds containing tantalum and niobium. The main types of tantalum- and niobium-containing minerals are discussed in Chapter 1, and typical compositions of such minerals are presented in Table 2. 

Since the fluorination enables to separate components of complex oxide compounds containing tantalum and niobium, it seems that it is applicable for... 

From this completed half-reaction we see that the conversion of methanol to formic acid involves the loss of four electrons. Since the oxidation of methanol to formaldehyde was only a two-electron change, it is clear that formic acid is a more highly oxidized compound of carbon than formaldehyde or methanol. 

K Fe(CN)6 oxidation Compound F is stoichiometrically inactivated by oxidation with K.3Fe(CN)6 (Shimomura and Johnson, 1967) thus, it is possible to estimate the molecular extinction coefficient (e) of the 388-390 nm absorption peak by titrating F with K.3Fe(CN)6- The e value obtained by the titration in 50% ethanol was 15,400 (assuming the reaction to be one-electron oxidation) or 30,800 (assuming two-electron oxidation). Two other methods of lesser precision were used to determine the true s value 1) the dry weight of the ethyl acetate extract of an acidified solution of F gave an e value of 14,100 2) the comparison of NMR signal intensities gave a value of 11,400 2,000 in water (H. Nakamura, Y. Oba, and A. Murai, 1995, personal... 

Nitric oxide compounds of transition metals. B. F. G. Johnson and J. A. McCleverty, Prog. Inorg. Chem., 1966,7, 277-359 (264). 

Therefore, CL and die depolymerized product from which CL is regenerated contain various impurities which are present in widely fluctuating amounts depending on the reclamation processes involved. In particular, the presence of cyclohexanone, cyclohexanone oxime, octahydrophenazine, aniline, and other easily oxidized compounds affects die permanganate number. Also volatile substances such as aniline, cyclohexylamine, cyclohexanol, cyclohexanone, nitrocy-clohexanone, and aliphatic amines may also be present in the CL.22... 

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