Of manganese metal

J. H. Downing, Elec. Fum. Proc. 44 (1986) J. P. Eaunce andJ. Y. Welsh, "The Production of Manganese Metal," presented at 105th MnnualMeeting... 

The reduction of manganese oxides by aluminum has been used for the production of manganese metal. The process is also a classic example to illustrate thermal energy management in a typical aluminothermic reduction process. 

The dust and fumes from the powder form of most manganese compounds, especially the oxides, are very toxic to plants, animals, and humans. Even inhaling small amounts is toxic. The powder form of manganese metal is flammable, and manganese fires cannot be extinguished with water. They must be smothered by sand or dry chemicals. 

Exchange Between Ions of Manganese. Metallic managanese was bombarded for forty-five minutes with a 4 micro-ampere beam of 5.8 million volt deuterons and the radioactive layer was dissolved. A special device was used with a Geiger counter for determining the amount of manganese, tagged by means of its radio-... 

A crystal of one form of manganese metal has Mn atoms at the corners of a simple cubic unit cell that is 6.30° A on edge (Example 13-7). 

Left) The pink mineral rhodochrosite is manganese carbonate, MnCOj. (Right) A pile of manganese metal. Manganese is an important element in steels that must withstand great shock, such as those used to construct rock crushers. 

SMO/PAT] Smoes, S., Pattje, W. R., Drowart, J., Thermodynamic study of the vaporization of manganese metal and manganese selenide by Knudsen-cell mass spectrometry, High Temp. ScL, 10, (1978), 109-130. Cited on pages 338, 339, 340, 551, 552. 

The search is on for catalysts to replace those containing toxic heavy metals. The addition of hydrogen chloride to acetylene to form vinyl chloride is catalyzed by mercuric chloride. Rhodium (III) chloride on activated carbon works just as well and is much less toxic 97 It should be tried also in other addition reactions of acetylene as well as in trans-esteriflcation reactions of vinyl acetate. The reduction of 2 ethyl-2-hexenal to 2-ethylhexanol can be catalyzed by a mixture of copper, zinc, manganese, and aluminum oxides in 100% yield.98 This is said to be a replacement for carcinogenic copper chromite. In Reaction 4.15, the amount of toxic chromium(II) chloride has been reduced from stoichiometric to catalytic (9-15 mol% chromium(II) chloride) by the addition of manganese metal.99... 

Self condensation of phthalonitrile or o-cyanobenzamide in the presence of manganese metal gives a product which, on sublimation, yields pure [MnPc]. Alternatively this product may be obtained by the reaction of phthalonitrile with manganese acetate. Although similarities exist, the chemistry of manganese phthalocyanine species show many differences to that of the corresponding porphyrins. ... 

A 2.747-g sample of manganese metal is reacted with excess HCI gas to produce 3.22 L H2(g) at 373 K and 0.951 atm and a manganese chloride compound (MnCIJ. What is the formula of the manganese chloride compound produced in the reaction ... 

A 7-g quantity of manganese metal as its nitrate salt is added slowly to 950 ml of water at 90°C. The mixture is stirred with a magnetic stirrer until all of the solid is dissolved. The solution is filtered while hot and then cooled and made up to a liter. The solution thus formed contains 7 g of manganese per liter of water. 

Table 2.52. Major producers of manganese metal Country Manganese producer...

We reported that Mn does, in fact, undergo oxidative addition to alkyl and benzylic tosylates and mesylates under mild conditions to yield the corresponding organomanganese tosylates and mesylates in excellent yields. To our knowledge, this is the first example of organomanganese tosylates and mesylates prepared via direct oxidative addition of manganese metal or by any metathesis approach. 

Umani-Ronchi adapted the Furstner protocol to achieve the first catalytic, enantioselective variant of this reaction. The chiral chromium salen complex was prepared from the in situ reduction of the anhydrous CrCb to CrCl2 with an excess of manganese metal, followed by complexation with the salen ligand 8 in the presence of catalytic triethylamine." Then the addition of allylic chloride (9) to aldehydes 10 to give the allylic alcohols 11 in moderate yields and in up to 95% ee. The same groups employed the same conditions for the addition of 2-butenyl bromides to aldehydes to achieve up to 83 17 syn/anti of allylic alcohol products and for the addition of 1,3-dichloropropene to aromatic aldehydes to obtain the syn chlorohydrin adduct in modest yield which were further converted to optically active vinyl epoxides. The [Cr(salen)]-catalyzed addition of propargyl halides to aromatic aldehydes allowed the synthesis of enantiomerically enriched homopropargyl alcohols in moderate yields with up to 56% ee. ... 

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