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A detailed chemical kinetic model has been developed for supercritical water oxidation (SCWO) of methylamine, CH3NH2, providing insight into the intermediates and final products formed in this process as well as the dominant reaction pathways. The model was adapted from previous mechanisms, with a revision of the peroxyl radical chemistry to include imine formation, which has recently been identified as the dominant gas-phase pathway in amine oxidation. The developed model can reproduce previous experimental data on methylamine consumption and major product formation to reasonable accuracy, although with deficiencies in describing the induction time. Our simulations indicate that oxidation of the •CH2NH2 radical to methanimine, CH2NH, is the major channel in methylamine SCWO, with subsequent hydrolysis of CH2NH providing the experimentally observed reaction products ammonia and formaldehyde. Integral-averaged reaction rates were used to identify major reaction pathways, and a first-order sensitivity analysis indicated that the concentration of CH3NH2 is most sensitive to OH radical kinetics. Overall, this work clarifies the importance of imine chemistry in the oxidation of nitrogen-containing compounds and indicates that they are necessary to model these compounds in SCWO processes. 相似文献
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Chemoselective hydrogenation of various aldehydes and ketones with methylamine borane (MeAB) in neat water was investigated. MeAB is suitable for green organic reactions, for MeAB is a nontoxic, environmentally benign, and easily handled reagent. Aldehydes were selectively and rapidly hydrogenated in excellent yields (86–97%) for 30 min, but hydrogenation of aromatic ketones needed over 20 h at room temperature because of their poor water solubility and steric hindrance. Thus we investigated polyethylene glycol (PEG400) and acidic cation-exchange D072 resin as catalysts to accelerate the hydrogenation reaction of aromatic ketones and achieved excellent yields within several hours. PEG 400 and D072 resin are both suitable for green organic reactions. The D072 resin was reused up to four times without any significance loss in activity. 相似文献
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Fatma S.M. Hassan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):406-417
Complexes of the type [Pt R2 (dppma-PP′)] (R─Me, Et, Ph, CH2Ph, C6H4 Me-p, C6H4OMe-2, CH2CMe3, 1-naphthyl, C6H4Me-o, dppma = Ph2PNMe PPh2) have been prepared from [PtCl2, (dppma-PP′)] and the corresponding alkyl-lithium or Grignard reagents. Equilibrium constants, k, for the conversion of [PtR2 (dppma-PP′)] into cis-[PtR2(dppma-P)2] with dppma were studied using 31P NMR spectroscopy at room temperature. Equilibrium is rapidly established for R─C6H4-Me-o, at 20°C. Complex of the type cis-[PtR2 (dppma-P)2] was isolated R─C6H4 Me-o. The complexes [PtMe2(dppma-P)2] and [Pt(o-methoxyphenyl)2(dppma-P)2] were prepared, but unfortunately decomposed once isolated, the only evidence for its formation being from 31P-{1H} NMZR spectroscopy. The o-tolyl or 1-naphthyl complexes exist as syn-anti mixtures in solution, due to restricted rotation around the platinum aryl bonds. Treatment of several complexes of the type [PtR2(dppma-PP′)] with MeI gives [PtR2Me(I)(dppma-PP′)] with trans addition of MeI. Treatment of [PtR2(dppma-PP′)] with HCl gives [Pt Cl (R) (dppma-PP′)] for R─C6H2Me3-2,4,6, C6H4-CH3-2, C6H4-Me-4, Me, 1-naphthyl. The 1H, 31P NMR parameters for these complexes are discussed. Attempted preparation of complexes of the type [PtR2 (dppma-P)2M] (R─C6H4-Me-2, Me CN-C6H4-Me-4); M─Pd, Pt, Au,) are reported. 相似文献
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甲基营养细菌No1甲胺脱氢酶是以色氨酸-色氨酰醌为辅基的一种特殊氧化还原酶.粗酶液经纯化后,其比活力和收得率分别为5.1nmol·g-1和28%.该酶的分子量为67000,等电点为8.3和8.5,组成它的大、小两个亚基的分子量分别为37000和15000.甲胺脱氢酶有较好的耐热性,它能催化包括一级甲胺和二胺在内的底物反应,与甲胺反应的Km值为26.6μmol·L-1,最适pH为8.0.其酶催化反应可被Cu2+抑制.该酶的吸收光谱是,在328nm和426nm呈现两个特征峰 相似文献
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Herewith are the two processes developed by Nitto, which produce N-containing compounds such as hydrogen cyanide and methylamines. These processes are characterized by unique selective catalysts: an Fe–Sb–O based fluid-bed catalyst for ammoxidation of methanol and a shape-selective zeolite catalyst for ammonolysis of methanol. 相似文献
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ZHANG Jin-chao SHEN Yong YANG Meng-su 《高等学校化学研究》2006,22(3):278-282
Introduction Cisplatinisoneofthemostactivechemotherapeu ticagentsavailableforthetreatmentofavarietyof cancers,especiallytesticularcancerandovariancanc er.However,itsclinicalutilityisrestrictedbyboththe drugresistanceandtoxicity.Sincethediscoveryofan tican… 相似文献
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《Electroanalysis》2005,17(14):1291-1301
The formation of complex species between lead and TAPSO, a commercialized biological buffer, was evidenced and discussed. Formation constants of Pb? (TAPSO)x? (OH)y system have been studied by direct current polarography and by glass electrode potentiometry at fixed total–ligand and total–metal concentration ratio and varied pH, at 25.0 °C and ionic strength set to 0.1 M KNO3. The graphic analysis revealed to be a very powerful tool in the prediction and refinement operations of Pb–(TAPSO)x? (OH)y system. The proposed final model for this system is: PbL, PbL2, PbL2(OH) and PbL2(OH)2, with stability constants values, as log β, of 3.7±0.1, 6.6±0.1, 12.9±0.1 and 17.8±0.1, respectively. 相似文献
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