MnO , preparation

Zotfaghari, A. et al.. Capacitive behavior of nanostructured MnO, prepared by sono-chemistry method, Electrochim. Acta. 52. 2806. 2007. 

Mn2(H2P202)2) is the stable product in the potentiometric deterrnination of manganese. Manganese(III) does not coordinate with amines or nitro complexes, but it does make manganicyanides of the types M2(Mn(CN)g) and M2(Mn(CN) (OH)), which are similar to the ferricyanides. The K", Na", LC and manganicyanides have been prepared and slowly hydroly2e in water to MnO(OH). 

MnO.F, is obtained as a green vapor when KMnO reacts with anhydrous HF. The highly unstable gaseous green-violet permanganyl chloride [15605-27-3], MnO Cl, is prepared bypassing dry HCl gas through a solution of KMnO in concentrated sulfuric acid at —50°C (104). 

Ketopantolactone (19) is conveniently prepared by oxidation of (R,5)-pantolactone (18). Various oxidising agents have been patented for the oxidation of pantolactone, such as MnO ( 1)> DMSO—AC2O (32), and hypohahtes (33). An improved yield of ketopantolactone (19) via electrolytic oxidation of pantolactone with an aqueous solution containing an alkaH metal salt was reported (34). Ketopantolactone (19) has been prepared in good yield via cyclocondensation of the 2-keto-3-methylbutyrate (20) with formaldehyde (35). 

The reaction mixture is filtered. The soHds containing K MnO are leached, filtered, and the filtrate composition adjusted for electrolysis. The soHds are gangue. The Cams Chemical Co. electrolyzes a solution containing 120—150 g/L KOH and 50—60 g/L K MnO. The cells are bipolar (68). The anode side is monel and the cathode mild steel. The cathode consists of small protmsions from the bipolar unit. The base of the cathode is coated with a corrosion-resistant plastic such that the ratio of active cathode area to anode area is about 1 to 140. Cells operate at 1.2—1.4 kA. Anode and cathode current densities are about 85—100 A/m and 13—15 kA/m, respectively. The small cathode areas and large anode areas are used to minimize the reduction of permanganate at the cathode (69). Potassium permanganate is continuously crystallized from cell Hquors. The caustic mother Hquors are evaporated and returned to the cell feed preparation system. 

Also of interest are the octacyano complexes, (M(CN)g] (M = Mo, W), whieh are commonly prepared by oxidation of the M" analogues (using MnO,) or Ce" ) and whose structures apparently vary, aceording to the environment and counter cation, between the energetically similar square-antiprismatic and dodecahedral forms. 

Mn(C104)i, mw 253.84, OB to MnO HC1 +25.2% the hexahydrate is obtained as pale rose needles (Ref 2) Qf ealed to be —90kcal/ mole (Ref 5) CA Registry No 13770-16-6 Preparation. The hexahydrate, Mn(H20) -(ClO02, has been prepd by dissolving Mn-hydroxide or carbonate in dil perchloric ac followed by evapn of the soln until crysts appear (Ref 2). Attempts to dehydrate it by heating with an excess of 2,2-dimethoxypropane resulted in severe explns when the temp was raised above 65° (Ref 6)... 

The green tetrahedral ion MnO " is stable in basic solution. It can be prepared by reducing MnOj with Fe(CN)g . There is uncertainty about the MnO "—H2O exchange rate. The ion disproportionates in acid and the kinetics have been studied by stopped-flow. At 610 nm where loss of MnO is monitored, the reaction is first-order. At 520 nm where formation of Mn04 is observed, the reaction is second-order. These observations and the H dependency suggest a mechanism... 

Finally, it was observed by STEM-EELS that a Co/Mn/Ti02 catalyst prepared by IWI clearly decreased the Co particle size after activation. Co particles of 5-10 nm were covered by MnO after reduction, and this was manifested in the F-T reaction as a decrease in activity. Hence, it was concluded that even when Mn is not mixed with the C03O4 in the calcined catalyst, upon reduction it may undergo changes, which lead to a covering and blocking of the small Co particles by the MnO phase. 

Mn,tCo3 t04) phase. This spinel oxide is broken up during reduction to make MnO t and a metallic surface. Due to the pre-existence of this Mn-M interaction, electronic promotion is much more easily achieved after reduction as well. It is worthwhile to mention that Mn,tCo3 t04 compounds are well studied in the literature, because they have important electrocatalytical properties. More specifically, spinel-type manganese oxides are widely used as precursors in the preparation of X-Mn02 ([ ]A[Mn2]B04], an oxide of technical interest due to its application as a cathode material for rechargeable cells. " ... 

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