Introduction of Manganese

Application of XPS to mixtures of Mn(N03)2 or MnS04 with H-ZSM-5 after solid-state reaction at 700-920 K in a stream of oxygen or hydrogen revealed that the same concentration of Mn + occurred at the external surface of the zeolite crystallites as that determined by chemical analysis for the bulk. Therefore, the authors [147] concluded that the incorporated cations were homogeneously distributed neither surface enrichment nor depletion had taken place. 

An instructive set of ESR spectra is displayed in Fig. 49. It is seen that the starting mixture of solid MnS04 and H-ZSM-5 did not exhibit any hyperfine splitting of the signal at g = 2.0 originating from Mn + in crystalline MnS04 

Essentially the same ESR features were observed by Reran et al. [188] when studying the system MnCyH-ZSM-S. In contrast, no ESR signals ascribable to isolated Mn cations on exchange sites of ZSM-5 were detected when the sodium form of the zeolite, i. e., Na-ZSM-5, was heated in a mixture with MnS04 and subsequently hydrated [147]. 

Solid-state reaction of MnCl2, MnS04,Mn304 or Mn(CH3COO)2 with H-ZSM-5 was also monitored by IR spectroscopic measurements of the consumption of acidic OH groups, i.e., the decrease in the intensity of the respective IR band at 3610 cm (cf. Fig. 50 and Table 11). 

Number of Mn cations related to the original number of the zeolite bridging OH groups (0.91 mmol per gram of dry zeolite). 

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This work has recently been extended, again with a single Pd/Al2O3 catalyst pellet 69). The image time was reduced to 34 s by introduction of manganese ions into the... 

The oxidation of organic compounds by manganese dioxide has recently been reviewed. It is of limited application for the introduction of double bonds, but the advantages of mildness and simple workup make it attractive for some laboratory-scale transformations. Manganese dioxide is similar to chloranil in that it will oxidize A -3-ketones to A -dienones in refluxing benzene. Unfortunately, this reaction does not normally go to completion, and the separation of product from starting material is difficult. However, Sondheimer found that A -3-alcohols are converted into A -3-ketones, and in this instance separation is easier, but conversions are only 30%. (cf. Harrison s report that manganese dioxide in DMF or pyridine at room temperature very slowly converts A -3-alcohols to A -3-ketones.)... 

The most satisfactory use of manganese dioxide for double bond introduction employs enol ethers as substrates ... 

The introduction of enamel into the wastestream results in an increase in the concentration of metals, but these metals (antimony, titanium, zirconium, tin, cobalt, and manganese) are in solid form whereas the metals generated by surface preparation are normally in dissolved form. These solid metals increase the suspended solids concentration of the stream. Other metals that may be found in the enamel preparation and application wastestream in significant amounts include aluminum, copper, iron, lead, nickel, and zinc. Table 8.2 presents pollutant sampling data for the processes used in the porcelain enameling on steel industry. 

Under the conditions where the chain oxidation process occurs, this reaction results in chain termination. In the presence of ROOH with which the ions react to form radicals, this reaction is disguised. However, in the systems where hydroperoxide is absent and the initiating function of the catalyst is not manifested, the latter has a retarding effect on the process. It was often observed that the introduction of cobalt, manganese, or copper salts into the initial hydrocarbon did not accelerate the process but on the contrary, resulted in the induction period and elongated it [4-6]. The induction period is caused by chain termination in the reaction of R02 with Mn"+, and cessation of retardation is due to the formation of ROOH, which interacts with the catalyst and thus transforms it from the inhibitor into the component of the initiating system. 

Chenot An early steelmaking process. Iron ore was first reduced to sponge iron this was mixed with charcoal, manganese, and resin and compressed into small blocks. These blocks were then melted as in the Crucible process. Invented by A. Chenot in France in 1846 and operated on a small scale in Sheffield in the 1860s, but abandoned after the introduction of the Open Hearth process. 

Calcium and particularly magnesium show excessive vapor pressure at steelmaking temperatures. Table I, but this alloyability problem has been somewhat alleviated bj - submerging the introduction of the calcium alloy under 3 meters of liquid steel (31) However, independently of vapor pressure, it is the low solubility of calcium in liquid iron which limits the effective substitution of >feiS by CaS to extremely low sulfur levels, particiilarly when the manganese content is high, 2% for example (32). 

There is concern that elevated environmental levels of manganese resulting, for example, from the introduction Mn-containing additives to petrol, might be associated with neurological disease. Direct EPR spectroscopy has been used to monitor Mn(II) following the addition of Mn(II) and Mn(III) complexes to human blood plasma and cell lysates.49... 

The production of industrially important perfluoroalkane sulfonic acids is generally accomplished by electrochemical fluorination. This method of preparation remains expensive and proceeds in good yields only for short hydrocarbon chains.30 Recently however, Wakselman and Tordeux have described a chemical method for the preparation of trifluoromethane sulfonic acid.31 The procedure involves reaction of a metal selected from zinc, cadmium, manganese, and aluminum with sulfur dioxide in DMF, followed by the introduction of trifluoromethyl bromide under slight pressure. The intermediate sulfinate is subsequently oxidized by hydrogen peroxide, and then hydrolyzed which leads to formation of the trifluoromethane sulfonic acid. Successful extension of the sulfination process to the modification of PCTFE should result in the formation of a sulfinated polymer which can ultimately be oxidized to give a sulfonic-acid modified polymer. 

An electrophilic substitution of potential synthetic value but one which is rarely utilized is the introduction of a mono- or di-acetoxymethyl group by the action of manganese(III) acetate on a coumarin. This ring system is more amenable than many to this reagent and a variety of products may be obtained by altering the ratio of reactants (Scheme 12) (79BCJ2386). 

Shortly after the introduction of the bismuth molybdate catalysts, SOHIO developed and commercialized an even more selective catalyst, the uranium antimonate system (4). At about the same time, Distillers Company, Ltd. developed an oxidation catalyst which was a combination of tin and antimony oxides (5). These earlier catalyst systems have essentially been replaced on a commercial scale by multicomponent catalysts which were introduced in 1970 by SOHIO. As their name implies, these catalysts contain a number of elements, the most commonly reported being nickel, cobalt, iron, bismuth, molybdenum, potassium, manganese, and silica (6-8). 

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