90-44-8Relevant articles and documents
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Bansho,Nukada
, p. 579 (1960)
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ON THE MECHANISM OF THE CATHODIC REDUCTION OF ANTHRAQUINONE TO ANTHRONE.
Beck,Heydecke
, p. 37 - 43 (1987)
The cathodic reduction of anthraquinone in 85% H//2SO//4 at cathodes of glassy carbon or mercury has been investigated. Voltammetric curves exhibit two steps at plus 0. 23 and plus 0. 10 V vs. SHE. The limiting current densities show a ratio between 4:0 via 1:1 to 1:3, depending on the experimental conditions. Experiments at the RRDE indicate two reoxidizable intermediates. We derive a mechanism from our findings, involving the electrochemical formation of these intermediates, anthrasemiquinone AQH multiplied by (times) and anthrahydroquinone AQH//2. Both are subject to a bimolecular follow up reaction (disproportionation) to yield AQH//2 and anthrone. The rate constants are estimated to be 2. 10**3 and 3. 10**4 1 mol** minus **1 s** minus **1, respectively. Anthrone is the only reduction product which could be isolated.
g-C3N4/metal halide perovskite composites as photocatalysts for singlet oxygen generation processes for the preparation of various oxidized synthons
Corti, Marco,Chiara, Rossella,Romani, Lidia,Mannucci, Barbara,Malavasi, Lorenzo,Quadrelli, Paolo
, p. 2292 - 2298 (2021/04/12)
g-C3N4/metal halide perovskite composites were prepared and used for the first time as photocatalysts forin situ1O2generation to perform hetero Diels-Alder, ene and oxidation reactions with suitable dienes and alkenes. The standardized methodology was made applicable to a variety of olefinic substrates. The scope of the method is finely illustrated and the reactions afforded desymmetrized hydroxy-ketone derivatives, unsaturated ketones and epoxides. Some limitations were also observed, especially in the case of the alkene oxidations, and poor chemoselectivity was somewhere observed in this work which is the first application of MHP-based composites forin situ1O2generation. The experimental protocol can be used as a platform to further expand the knowledge and applicability of MHPs to organic reactions, since perovskites offer a rich variety of tuning strategies which may be explored to improve reaction yields and selectivities.
Ligand-Constraint-Induced Peroxide Activation for Electrophilic Reactivity
Ansari, Mursaleem,Chandra, Anirban,Kundu, Subrata,Monte-Pérez, Inés,Rajaraman, Gopalan,Ray, Kallol
supporting information, p. 14954 - 14959 (2021/06/01)
μ-1,2-peroxo-bridged diiron(III) intermediates P are proposed as reactive intermediates in various biological oxidation reactions. In sMMO, P acts as an electrophile, and performs hydrogen atom and oxygen atom transfers to electron-rich substrates. In cyanobacterial ADO, however, P is postulated to react by nucleophilic attack on electrophilic carbon atoms. In biomimetic studies, the ability of μ-1,2-peroxo-bridged dimetal complexes of Fe, Co, Ni and Cu to act as nucleophiles that effect deformylation of aldehydes is documented. By performing reactivity and theoretical studies on an end-on μ-1,2-peroxodicobalt(III) complex 1 involving a non-heme ligand system, L1, supported on a Sn6O6 stannoxane core, we now show that a peroxo-bridged dimetal complex can also be a reactive electrophile. The observed electrophilic chemistry, which is induced by the constraints provided by the Sn6O6 core, represents a new domain for metal?peroxide reactivity.
A Synthetic Model for the Possible FeIV2(μ-O)2Core of Methane Monooxygenase Intermediate Q Derived from a Structurally Characterized FeIIIFeIV(μ-O)2Complex
Aono, Yuri,Harada, Masafumi,Kajiwara, Atsushi,Katano, Hajime,Kobayashi, Yoshio,Kodera, Masahito,Kotegawa, Fukue,Kubo, Minoru,Matsumoto, Arimasa,Mikata, Yuji,Nakayama, Hiromi,Yamamoto, Chihiro,Yanagisawa, Sachiko
supporting information, (2021/12/09)
A bis(μ-oxo)diiron(IV,IV) complex as a model for intermediate Q in the methane monooxygenase reaction cycle has been prepared. The precursor complex with a [FeIIIFeIV(μ-O)2] core was fully characterized by X-ray crystallography and other spectroscopic analyses and was converted to the [FeIV2(μ-O)2] complex via electrochemical oxidation at 1000 mV (vs Ag/Ag+) in acetone at 193 K. The UV-vis spectral features, M?ssbauer parameters (ΔEQ = 2.079 mm/s and δ= -0.027 mm/s), and EXAFS analysis (Fe-O/N = 1.73/1.96 ? and Fe···Fe = 2.76 ?) support the structure of the low-spin (S = 1, for each Fe) [FeIV2(μ-O)2] core. The rate constants of the hydrogen abstraction reaction from 9,10-dihydroanthracene at 243 K suggest the high reactivity of these synthetic bis(μ-oxo)diiron complexes supported by simple N4 tripodal ligand.
