Search results for "Oxidations"
showing 7 items of 7 documents
Chemistry and reactivity of dinuclear manganese oxamate complexes: Aerobic catechol oxidation catalyzed by high-valent bis(oxo)-bridged dimanganese(I…
2006
[EN] The high-valent bis(oxo)-bridged dimanganese(IV) complexes with the series of binucleating 4.5-X-2-o-phenylenebis(oxamate) ligands (opbaX(2); X = H, Cl, Me) (1a-c) have been synthesized and characterized structurally, spectroscopically and magnetically. Complexes la-c possess unique Mn-2(mu-O)(2) core structures with two o-phenylenediamidate type additional bridges which lead to exceptionally short Mn-Mn distances (2.63-2.65 angstrom) and fairly bent Mn-O-Mn angles (94.1 degrees-94.6 degrees). The cyclovoltammograms of la-c in acetonitrile (25 degrees C, 0.1 M Bu4NPF6) show an irreversible one-electron oxidation peak at moderately high anodic potentials (E-ap = 0.50-0.85 V versus SCE),…
Chemistry and reactivity of dinuclear iron oxamate complexes: alkane oxidation with hydrogen peroxide catalysed by an oxo-bridged diiron(III) complex…
2004
[EN] A new dinuclear iron(III) complex with the tetradentate ligand N,N'-o-phenylenebis(oxamate) (opba) has been synthesised, and structurally, magnetically and electrochemically characterised. It possesses an unprecedented triply bridged Fe-2(mu-O)(mu-RCO2...H2O...O2CR)(2) core, whereby two N-amides from the opba ligand complete the square-pyramidal coordination sphere of the O-carboxylate rich iron site (Fe-N = 2.053 Angstrom and Fe-O = 2.015 Angstrom), The antiferromagnetic exchange interaction between the two high-spin Fe-III ions through the oxo bridge (J = -190 cm(-1); H = -JS(1)(.)S(2)) is weaker than that found in related mu-oxo singly bridged diiron(III) complexes. The lessened ant…
Different preparation methods of bare and doped carbon nitride (C3N4) employed for selective photocatalytic oxidations
2018
Different preparation methods of bare and doped carbon nitride (C3N4) employed for selective photocatalytic oxidations
Titania Photocatalysts for Selective Oxidations in Water
2011
Heterogeneous photocatalysis by polycrystalline semiconductor oxides is an unconventional technology that has been mainly applied for the degradation of organic and inorganic pollutants in both the vapor and liquid phase. The application of photocatalysis in synthetic routes has also been researched in recent years, demonstrating its viability as an alternative route in organic chemistry. This work illustrates the main findings in the application of heterogeneous photocatalysis to the oxidation of organic compounds dissolved in water, free of any organic co-solvent. Two main aspects of the oxidative process have been studied: the first one is the partial oxidation of various mono-substitute…
Chemistry and reactivity of mononuclear manganese oxamate complexes: Oxidative carbon-carbon bond cleavage of vic-diols by dioxygen and aldehydes cat…
2006
[EN] Two new mononuclear octahedral manganese(III) complexes with the tetradentate equatorial ligand o-phenylenebis(oxamate) (opba) and two aquo (1a) or two pyridine (1b) axial ligands have been synthesized and characterized structurally, magnetically, and electrochemically. The cyclovoltammogram of 1a in acetonitrile (25 degrees C, 0.1 M Bu4NPF6) shows an irreversible one-electron oxidation peak at a high anodic potential (E-ap = 1.03 V versus SCE), while that of 1b shows two well-separated one-electron oxidation peaks at moderate to high anodic potentials (E-ap = 0.92 and 1.27 V versus SCE), the first redox-wave being quasireversible in nature. The access to formally high-valent Mn-IV and…
Photooxidations of Alkenes in Fluorinated Constrained Media: Fluoro-organically Modified NaY as Improved Reactors for Singlet Oxygen “Ene” Reactions
2007
Creating a stationary fluorinated environment inside the zeolite cavity can increase the reactivity observed for intrazeolite photooxidation of alkenes. Exchanging the zeolite with fluorinated organic cations is a much more effective strategy than simply using a fluorinated solvent for slurry irradiations. Use of cations containing C-F bonds is also more efficient than use of deuterated cations for creation of a singlet oxygen friendly environment where the quenching processes are slowed down. Doping the zeolite with fluoro-organic cation 4 resulted in an increase in the singlet oxygen lifetime to 12 micros.
Molybdenum(VI) complexes with a chiral L-alanine bisphenol [O,N,O,O’] ligand : Synthesis, structure, spectroscopic properties and catalytic activity
2023
Dioxidomolybdenum(VI) compound [MoO2Cl2(dmso)2] reacts with a chiral tetradentate O3N-type L-alanine bisphenol ligand precursor (Et3NH)H2Lala to form an oxidochloridomolybdenum(VI) complex [MoOCl(Lala)] (1) as two separable geometric isomers with phenolate groups in cis or trans positions. The single crystal X-ray and NMR analyses of cis- and trans-1 reveal that the complexes are formed of monomeric molecules, in which the ligand has a tetradentate coordination through three oxygen donors and one nitrogen donor. The reaction of Na2MoO4·2H2O with the same ligand precursor in an acidic methanol solution leads to the formation of an anionic dioxido complex (Et3NH)[MoO2(Lala)] (2) with a trans …