107997-80-8Relevant articles and documents
Phototransformation of 5-nitro-2-furaldehyde in aqueous solution. A laser flash photolysis and product analysis study
Martins, Luis J.A.,Ferreira, Jo?o M. M.
, p. 721 - 735 (2017)
Laser flash photolysis of 5-nitro-2-furaldehyde (NFA) in solution shows a short-lived transient absorption with λmax = 475 ± 5 nm, which is relatively insensitive to solvent polarity and is assigned to the lowest triplet state of NFA (3NFA?). In water, the 3NFA? absorption decays to a long-lived absorption, the study of which, at different times after the end of the laser pulse, reveals it to be due to a furyloxyl radical (λmax ≈ 375 nm) and to the radical anion NFA- (λmax ≈ 400 nm). These radicals were produced independently to confirm the assignment. The lifetime of 3NFA? depends both on the solvent and the ground-state concentration of NFA. An (n, π?) nature is attributed to 3NFA? on the basis of the propensity of 3NFA? to abstract a hydrogen-atom from the solvent. Kinetic evidence for triplet excimer formation was obtained from the self-quenching of 3NFA? in solvents where the triplet decay is slower. The effect of acidity on the triplet lifetime is discussed with respect to an electron-transfer self-quenching mechanism, assisted by the triplet excimer which is proposed to dissociate into radical ions. Chromatographic and spectroscopic analysis of the photolysed aqueous solution of NFA enabled the identification of 5-hydroxymethylene-2(5H)-furanone, nitrite ion and an unknown substance as the major photoproducts. Conclusive evidence is presented that the observed 5-hydroxymethylene-2(5H)-furanone is formed from the furyloxyl radical. It is shown that the unknown substance can also be obtained from both the photoreduction of NFA in propan-2-ol and chemical reduction of NFA by Fe(s) in water (along with 5-amino-2-furaldehyde). Based on 1H- and 13C-NMR (with 2-D HMQC) and vibrational absorption spectroscopy, a tentative structure is proposed for the substance of tR 3.69 minutes obtained as a photoreduction product of NFA in water. Inorganic anions are shown to be one-electron oxidised by 3NFA? (as indicated by the observation of both the radical anion of NFA and the inorganic radical) with second-order rate constants being dependent on E17 of the inorganic radical. The implications of the results from complete quenching of 3NFA? by inorganic anions, and subsequent product analysis, for the phototransformation mechanism of NFA in water are discussed.
Insights into the hydrothermal stability of ZSM.5 under relevant biomass conversion reaction conditions
Gardner, David W.,Huo, Jiajie,Hoff, Thomas C.,Johnson, Robert L.,Shanks, Brent H.,Tessonnier, Jean-Philippe
, p. 4418 - 4422 (2015)
Zeolite catalysts used for the conversion of carbohydrates to renewable platform chemicals in the condensed phase are shown to be sensitive to the presence of inorganic salts which alter the zeolite surface chemistry. The presence of NaCl (0.07-37 wt %) enhances the hydrolysis of Si-O-Al bridges and the release of Al3+ species that catalyze the conversion of glucose through homogeneous catalytic processes and obscure the apparent reactivity of the zeolite catalyst.
A catalytic oxidation fragrant boron class compound preparing phenol method (by machine translation)
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Paragraph 0073; 0099; 0100, (2017/08/08)
The invention discloses a method for catalytic oxidation of phenolic compounds fragrant boron class compound synthesis method, the flux in the solvent in the aqueous solution, under the action of alkali, adding hydrazine hydrate or acid hydrazides catalyst, catalytic oxidation fragrant boron class compound directly for the preparation of phenolic compound. The invention of the method of preparation of the phenol compound, the catalyst is a cheap hydrazine hydrate or hydrazine compound, the oxidizing agent is atmospheric pressure of air or oxygen, the reaction does not need good and activeness metal catalyst, is extensive and stable substrate, substrate-sensitive functional group compatibility good and wide range of application. In the optimized under the reaction conditions, the yield of the target product separation up to 99%. (by machine translation)
