MANGANESE.163 RUTHENIUM

Sometimes, a direct ion-pairing of the chiral cations and anions 8 or 15 is necessary to maximize the NMR separation of the signals [115,116]. Cationic species as different as quaternary ammonium, phosphonium, [4]heterohelice-nium, thiiranium ions, (rj -arene)manganese, ruthenium tris(diimine) have been analyzed with success (Fig. 23). 

G. E. Herberich, B. Hessner, W. Boveleth, H. Luthe, R. Saive, and L. Zelenka, A Novel and General Route to (ps-Borole)metal Complexes Compounds of Manganese, Ruthenium, and Rhodium, Angew. Chem. Int. Ed. Engl. 22, 996 (1983). 

The Chemical Shifts of the Carbonyl Ligand in Some Derivatives of Manganese, Ruthenium, Osmium, Cobalt,... 

Oxo-transfer from metal complexes to olefins results in a net two-electron reduction at the metal center. As a result, only metals capable of shuttling between oxidation states can be effective oxo-transfer catalysts. Iron, manganese, ruthenium, and chromium have proven effective for catalytic epoxidation via oxo-transfer [8,9], and in synthetic systems studied thus far for enantioselective catalysis, these metals are most commonly coordinated by tetradentate porphyrin (1) and salen (2) ligand frameworks (Fig. 1). 

Example 14.3. The Belousov-Zhabotinsky reaction [22,27-29], The reaction is an oxidation of malonic acid by bromate ion in sulfuric acid, catalyzed by a Ce(III)/Ce(IV) redox couple. Many variations with other organic acids and transition-metal ions are possible [22] (Belousov used citric acid, and manganese, ruthenium, or iron can replace cerium). The color of the solution alternates between clear [Ce(III)] and pale yellow [Ce(IV)], and more dramatically between red and blue if ferroin is added as indicator. 

The oxidation potential represents the ability of a metal atom (M) to be ionized to an ion (M" ") with loss of an electron. For the oxidation of organic molecules, transition metal compounds containing chromium, manganese, ruthenium, selenium, silver, or cerium are often used. The oxidation potential is therefore a useful method for examining the oxidizing power of these reagents. 

Keywords HNO NO Nitroxyl Azanone Nitroxyl anion Nitrosyl Porphyrin Heme Iron Manganese Ruthenium Cobalt Reductive nitrosylation Kinetics Oxidation Protein Myoglobin NOS. 

Also cationic complexes of arenes with iron, manganese, ruthenium, and osmium proved to be appropriate substrates for nucleophilic C-H fimctionalization according to the same addition-oxidation protocol Sn (AO), as illustrated by the reaction of cationic mesitylene-tricarbonylmanganese with the cyanide anion (Scheme 26) [11, 112]. 

Titanium covered by platinum or by dioxide of manganese, ruthenium, iridium or other substances is most commonly used as an anode. Graphite and graphite covered with lead dioxide have also been used as anodes. Under some conditions, high pH and absence of salts in the anolyte, nickel can be used as the anode. Stainless steel is commonly used as the cathode. If current reversal is employed, the same material, platinized titanium or graphite, is used for both electrodes. Electrode chambers should be flushed with a large flow of rinse solution in order to remove the electrode reaction products. 

Aue WA and Singh H (2001) Chemiluminescent photon yields measured in the flame photometric detector on chromatographic peaks containing sulfur, phosphorus, manganese, ruthenium, iron or selenium. Spectrochimica Acta Part B 56 517-525. 

G.E. Herberich - A Novel and General Route to Metal (ii -Borole)Complexes Compounds of Manganese, Ruthenium and Rhodium,... 

Electrochemical methods. Hie electrolysis of dilute sulfuric acid solutions with a mercury cathode results In the quantitative deposition of Cr, Fe, Co, Nl, Cu, Zn, Qa, Oe, Mo, Rh, Pd, Ag, Cd, In, Sn, Re, Ir, Pt, Au, Hg, and T1 In the cathode. i Arsenic, selenium, tellurium, osmium, and lead are quantitatively separated from the electrolyte, but are not quantitatively deposited In the cathode. Manganese, ruthenium, and antimony are Incompletely separated. Uranium and the remaining actinide elements, rare earth elements, the alkali and alkaline eeu th metals, aluminum, vanadium, zirconium, niobium, etc. remain In solution.Casto and Rodden and Warf— have reviewed the effects of many variables In the electrolytic separation of the above-named elements from uranium. According to Rodden and Warf optimum conditions for the purification of uranium In sulfuric acid solutions with a mercury cathode are electrolyte volume,... 

Because of the considerable corrosivity of chlorine toward most metals, anodic chlorine evolution can only be realized for a few electrode materials. In industry, graphite had been used primarily for this purposes in the past. Some oxide materials, manganese dioxide for instance, are stable as well. At present the titanium-ruthenium oxide anodes (DSA see Chapter 28) are commonly used. 

A wider application of ruthenium oxide capacitors is hindered by the high cost of ruthenium oxide. Attempts have been reported, therefore, to substitute ruthenium oxide with other, cheaper materials capable of intercalation and deintercalation of hydrogen and/or other ions. Promising results with pseudocapacities of about 100 F/g have been obtained with the mixed oxides of ruthenium and vanadium and also with mixed oxides on the basis of manganese oxide. 

These reports sparked off an extensive study of metalloporphyrin-catalyzed asymmetric epoxidation, and various optically active porphyrin ligands have been synthesized. Although porphyrin ligands can make complexes with many metal ions, mainly iron, manganese, and ruthenium complexes have been examined as the epoxidation catalysts. These chiral metallopor-phyrins are classified into four groups, on the basis of the shape and the location of the chiral auxiliary. Class 1 are C2-symmetric metalloporphyrins bearing the chiral auxiliary at the... 

Sun, L. Hammarstrom, L. Akermark, B. Styring, S. 2001. Towards artificial photosvthesis Ruthenium-manganese chemistry for energy production. Chem. Soc. Rev. 30 36 19. 

An asymmetric C-H insertion using a chiral 3,3, 5,5 -tetrabromosubstituted (salen)manganese(m) complex 107 with TsN=IPh afforded insertion products with ee up to 89%.258 Che reported the first amidation of steroids such as cholesteryl acetate with (salen)ruthenium(n) complexes 108.259... 

In company with manganese porphyrin complex, ruthenium porphyrins have already shown great catalytic activity in the intermolecular amidation of saturated G-H bonds. However, examples of amidation of aromatic... 

As shown in the manganese- and ruthenium-catalyzed intermolecular nitrene insertions, most of these results supposed the transfer of a nitrene group from iminoiodanes of formula PhI=NR to substrates that contain a somewhat activated carbon-hydrogen bond (Scheme 14). Allylic or benzylic C-H bonds, C-H bonds a to oxygen, and very recently, Q spz)-Y bonds of heterocycles have been the preferred reaction sites for the above catalytic systems, whereas very few examples of the tosylamidation of unactivated C-H bonds have been reported to date. 

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