Fe2 Ni

TBA4H6(Fe2- Ni(0Ac)3)PW9037 Alkane Alkene Aldehyde Alcohol, ketone Allylic alcohol, allylic ketone, epoxide Carboxylic acids 02 or h2o2 o2 o2 MeCN 82 °C or 50 °C 30 °C 30 °C 403... 

Polyoxometalates with the required redox properties can also be used in a straightforward manner as autooxidation catalysts. In this way the trisubstituted Keggin compound, [M3(H20)3PW9037] (M = Fe" and Cr ") and [Fe2M(H20)3PW9037 (M = Ni", Co , Mn and Zn ) were used in the autooxidation of alkanes such as propane and isobutane to acetone and tert-butyl alcohol [61]. Later [Fe2. Ni(0Ac)3PW9037] was prepared and used to oxidize alkanes such as adamantane. 

Tlie isolable stable 1,2-dithietaiie, dithiatopazine (73), was prepared in 1988 and fully characterized (the name dithiatopazine was coined for its beautifully yellow-orange topazlike crystalline form) (87JA3801 88JA4856 90JA3029). Tlius, controlled photoirradiation of a dithiono-lactone (117) produced 73 in 65% yield along with an alkene 118 in 12% yield. Photolytic or thermal decomposition of 73 led to the alkene 118, a conversion that could be also carried out by a variety of reagents [m-BusShH-AIBN, Raney Ni, MCPBA, Fe2(CO)9, Mo(CO)6] in excellent yields. 

Dimethyl-l,2,2,3-tetramethyl-A -1,2,5-azasilaboroline with [Fe2(CO)9] gives sandwich 62 and sandwich 63 (82AGE207, 82CB738) with Cp)Co(C2H4)2]. With [Ni(CDT)] or in a vapor phase with metallic nickel, sandwich 64 (M =Ni) is formed. The vapor-phase synthesis with iron gives 64 (M = Fe). In all these sandwiches, 62-64, the j " -coordination of the heterocyclic ligand is realized. 

The Lewis bases attached to the central metal atom or ion in a d-metal complex are known as ligands they can be either ions or molecules. An example of an ionic ligand is the cyanide ion. In the hexacyanoferrate(II) ion, [Fe(CN)6]4, the CN- ions provide the electron pairs that form bonds to the Lewis acid Fe2+. In the neutral complex Ni(CO)4, the Ni atom acts as the Lewis acid and the ligands are the CO molecules. 

Pentaphenylborole reacts with Pt(COD)2, Ni(CO)4 and Fe2(CO), to form stable pentaphenylborole-transition-metal complexes ... 

The first electrochemical H2 generation catalyzed by a hetero-nuclear Fe-Ni complex [Ni(L)Fe2(CO)g] (27) [L - = (CH3C6H3S2)2(CH2)3 ] (Fig. 9) with tri-fluoroacetic acid was reported by Schoder and coworkers in 2006 [211]. Based on their electrochemical behavior, spectroscopic data, and DFT calculations of 27, an EECC mechanism was mled out and therefore an ECCE or ECEC mechanism involving the formation of Fe°-H and Ni -H intermediates is likely. In this cycle, six catalytic turnovers were achieved. This value is comparable to those for... 

A novel polysiloxane, containing the isocyanide group pendent to the backbone, has been synthesized. It is observed to react with the metal vapors of chromium, iron and nickel to afford binary metal complexes of the type M(CN-[P])n, where n = 6, 5, 4 respectively, in which the polymer-attached isocyanide group provides the stabilization for the metal center. The product obtained from the reaction with Fe was found to be photosensitive yielding the Fe2(CN-[P])q species and extensive cross-linking of the polymer. The Cr and Ni products were able to be oxidized on exposure of thin films to the air, or electrochemically in the presence of an electron relay. The availability of different oxidation states for the metals in these new materials gives hope that novel redox-active polymers may be accessible. 

Hiratsuka et al102 used water-soluble tetrasulfonated Co and Ni phthalocyanines (M-TSP) as homogeneous catalysts for C02 reduction to formic acid at an amalgamated platinum electrode. The current-potential and capacitance-potential curves showed that the reduction potential of C02 was reduced by ca. 0.2 to 0.4 V at 1 mA/cm2 in Clark-Lubs buffer solutions in the presence of catalysts compared to catalyst-free solutions. The authors suggested that a two-step mechanism for C02 reduction in which a C02-M-TSP complex was formed at ca. —0.8 V versus SCE, the first reduction wave of M-TSP, and then the reduction of C02-M-TSP took place at ca. -1.2 V versus SCE, the second reduction wave. Recently, metal phthalocyanines deposited on carbon electrodes have been used127 for electroreduction of C02 in aqueous solutions. The catalytic activity of the catalysts depended on the central metal ions and the relative order Co2+ > Ni2+ Fe2+ = Cu2+ > Cr3+, Sn2+ was obtained. On electrolysis at a potential between -1.2 and -1.4V (versus SCE), formic acid was the product with a current efficiency of ca. 60% in solutions of pH greater than 5, while at lower pH... 

Ogura et a/.153 reduced C02 to methanol using the so-called Everitt s salt (K2Fe2+[Fe2+(CN)6])-modified electrode by a somewhat complicated but interesting route in the presence of a metal complex, such as Fe(II), Co(II), and Ni(II) complexes of 1-nitroso-2-naphthyl-3,6-disulfonic acid, and additional methanol ... 

Zinc, Cu and Ni have similar ionic radii and electron configurations (Table 5.6). Due to the similarity of the ionic radii of these three metals with Fe and Mg, Zn, Cu and Ni are capable of isomorphous substitution of Fe2+ and Mg2+ in the layer silicates. Due to differences in the electronegativity, however, isomorphous substitution of Cu2+ in silicates may be limited by the greater Pauling electronegativity of Cu2+ (2.0), whereas Zn2+ (1.6) and Ni2+ (1.8) are relatively more readily substituted for Fe2+ (1.8) or Mg2+ (1.3) (McBride, 1981). The three metals also readily coprecipitate with and form solid solutions in iron oxides (Lindsay, 1979 Table 5.7). 

The binary metal carbonyls are named by giving the name of the metal followed by the name carbonyl, with the number of carbonyl groups indicated by the appropriate prefix. For example, Ni(CO)4 is nickel tetracarbonyl, whereas Cr(CO)6 is chromium hexacarbonyl. If more than one metal atom is present, the number is indicated by a prefix. Thus, Co2(CO)8 is dicobalt octacarbonyl, and Fe2(CO)9 has the name diiron nonacarbonyl. 

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