Cobalt manganese and

Driers. These are generally soaps of cobalt, manganese, and other metals formed with organic acids such as linoleic, naphthenic, and other organic acids. They catalyze oxidation of drying oils (qv), and thus are used in inks that dry by oxidation (see Driers and metallic soaps). 

Concentration limits of the diphosphate-ion, admissible to determination of magnesium and cobalt, manganese and cobalt, zinc and cobalt by spectrophotometric method with application of the l-(2-pyridylazo)-resorcinol (PAR) are presented. Exceeding maintenance of the diphosphate-ion higher admissible supposes a preliminary its separation on the anionite in the H+-form. The optimum conditions of cobalt determination and amount of the PAR, necessary for its full fastening are established on foundation of dependence of optical density of the cobalt complex with PAR from concentration Co + and pH (buffer solutions citrate-ammoniac and acetate-ammoniac). 

Cobalt, Manganese, and Silver Catalysts for Reactions of Azomethine Ylides... 

Discussion. Various metals (e.g. aluminium, iron, copper, zinc, cadmium, nickel, cobalt, manganese, and magnesium) under specified conditions of pH yield well-defined crystalline precipitates with 8-hydroxyquinoline. These precipitates have the general formula M(C9H6ON) , where n is the charge on the metal M ion [see, however, Section 11.11(c)]. Upon treatment of the oxinates with dilute hydrochloric acid, the oxine is liberated. One molecule of oxine reacts with two molecules of bromine to give 5,7-dibromo-8-hydroxyquinoline ... 

Determination of copper as copper(I) thiocyanate Discussion. This is an excellent method, since most thiocyanates of other metals are soluble. Separation may thus be effected from bismuth, cadmium, arsenic, antimony, tin, iron, nickel, cobalt, manganese, and zinc. The addition of 2-3 g of tartaric acid is desirable for the prevention of hydrolysis when bismuth, antimony, or tin is present. Excessive amounts of ammonium salts or of the thiocyanate precipitant should be absent, as should also oxidising agents the solution should only be slightly acidic, since the solubility of the precipitate increases with decreasing pH. Lead, mercury, the precious metals, selenium, and tellurium interfere and contaminate the precipitate. 

Garnham, G. W., Codd, G. A. and Gadd, G. M. (1992). Kinetics of uptake and intracellular location of cobalt, manganese and zinc in the estuarine green alga Chlorella salina, Appl. Microbiol. Biotechnol., 37, 270-276. 

The most common simple cations in the soil solution are calcium (Ca2+), magnesium (Mg2+), potassium (K+), and sodium (Na+). Other alkali and alkaline-earth elements, when present, will be as simple cations also. Iron, aluminum, copper, zinc, cobalt, manganese, and nickel are also common in soil. Iron is present in both the ferrous (Fe2+) and ferric (Fe3+) states, while aluminum will be present as Al3+. Copper, zinc, cobalt, and nickel can all be present in one or both of their oxidations states simultaneously. Manganese presents a completely different situation in that it can exist in several oxidation states simultaneously. 

Meanwhile attempts to find an air oxidation route directly from p-xylene to terephthalic acid (TA) continued to founder on the relatively high resistance to oxidation of the /Moluic acid which was first formed. This hurdle was overcome by the discovery of bromide-controlled air oxidation in 1955 by the Mid-Century Corporation [42, 43] and ICI, with the same patent application date. The Mid-Century process was bought and developed by Standard Oil of Indiana (Amoco), with some input from ICI. The process adopted used acetic acid as solvent, oxygen as oxidant, a temperature of about 200 °C, and a combination of cobalt, manganese and bromide ions as catalyst. Amoco also incorporated a purification of the TA by recrystallisation, with simultaneous catalytic hydrogenation of impurities, from water at about 250 °C [44], This process allowed development of a route to polyester from purified terephthalic acid (PTA) by direct esterification, which has since become more widely used than the process using DMT. 

Silicon and germanium hydrides react with cobalt, manganese and rhenium carbonyls affording complexes having a silicon (or germanium)-metal bond. These reactions, described previously for inactive compounds have been used in the synthesis of optically active silyl and germyl-transition metals ... 

Terephthalic acid is commonly abbreviated TA or TPA. The abbreviation PTA (P = pure) is reserved for the product of 99% purity for polyester manufacture. For many years polyesters had to be made from dimethyl terephthalate (DMT) because the acid could not be made pure enough economically. Now either can be used. TA is made by air oxidation of /7-xylene in acetic acid as a solvent in the presence of cobalt, manganese, and bromide ions as catalysts at 200°C and 400 psi. TA of 99.6% purity is formed in 90% yield. This is called the Amoco process. 

An inhibition mechanism involving electron transfer between a chain-propagating radical and the antioxidant has frequently been suggested but has rarely been identified with any certainty. This process remains one of the least understood of all inhibition mechanisms. Probably the most clear-cut example of inhibition by one electron transfer (either partial or complete) has come from studies of metal-catalyzed oxidations. Many workers have reported that under certain conditions transition metals may inhibit rather than catalyze oxidations. Cobalt, manganese, and copper are particularly prominent in this respect. 

In view of the data, this novel reaction is unlikely to proceed by any mechanism known for other epoxidation reactions. There are several facts that argue strongly against a free radical mechanism. Our data show that the reaction is not affected by the presence of oxygen in contrast to the work of Indictor and Brill (6). Complexes of cobalt, manganese, and iron, which are most effective in converting peroxides to radicals (5,8), are not catalysts for this reaction. This reaction is stereospecific, and therefore must proceed by an ionic mechanism. 

Laser Hardening and Modification. Lasers are used to surface harden ductile steels and improve the toughness to a depth of 0.35 min or more. Lasers can also be used to bond solid or powder coatings to a surface. Typical coalings are nickel or titanium carbide on iron, and nickel, cobalt, manganese, and titanium carbide. TiC. on aluminum. I1 sc of lasers with other specialized coating methods is common. 

The importance of dose is well illustrated by metals that are essential in the diet but are toxic at higher doses. Thus iron, copper, magnesium, cobalt, manganese, and zinc can be present in the diet at too low a level (deficiency), at an appropriate level (maintenance), or at too high a level (toxic). The question of dose-response relationships is fundamental to toxicology (see Section 1.2). 

Steel A metal alloy that contains iron as its main ingredient along with some carbon and is hard, durable, and able to be shaped into different forms. Steel may contain a number of other elements including nickel, cobalt, manganese, and several other metals. 

Obirai J, Nyokong T (2005) Synthesis, electrochemical and electrocatalytic behaviour of thiophene-appended cobalt, manganese and zinc phthalocyanine complexes. Electrochim Acta 50(27) 5427-5434... 

The rather drastic conditions are required because in this particular case the COOH group deactivates the intermediate p-toluic acid towards further oxidation, and some p-carboxybenzaldehyde is found as a side-product, which is hydrogenated back to p-toluic acid. Other than that, a large number of functional groups are tolerated (see Table 4.7) [129]. The combination of cobalt, manganese and bromide ions is essential for optimum performance. The benzylic radicals are best generated with bromine atoms (see above) which in turn are more easily produced... 

Encouraging re ul) have aJ o been obtained by A. L. Dem with cobalt manganese and tron manganese systems (138]. Ethylene selectivities of 45% could be observed with the Co/Mn system. 

Alloy steel a form of steel containing carbon plus other metals such as chromium, cobalt, manganese, and molybdenum. (20.2) Alpha (a) particle a helium nucleus. (21.1)... 

Olivine is a major reservoir for divalent transition metal cations in xenoliths. Nickel, manganese, cobalt, and zinc all show correlations with Fo content in olivine from xenoliths. Nickel is positively correlated with Fo content, whereas cobalt, manganese, and zinc are negatively correlated suggesting the latter behave moderately incompatibly during the melting... 

Six paramagnetic ions occur in biological materials as trace metals . They are iron, copper, molybdenum, cobalt, manganese and vanadium, and each will be discussed in turn in the following sections. 

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