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本文以低碳烷烃的选择催化氧化反应为对象 ,对几种 CO2 选择氧化低碳烷烃的反应工艺进行了归纳总结 ,重点分析讨论了催化氧化反应中 CO2 作为氧化剂的作用机制 ,并提出了研究展望。 相似文献
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本文以低碳烷烃的选择催化氧化反应为对象,对几种CO2选择氧化低碳烷烃的反应工艺进行了归纳总结,重点分析讨论了催化氧化反应中CO2作为氧化剂的作用机制,并提出了研究展望。 相似文献
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直链烷烃物理性质递变规律研究 总被引:1,自引:0,他引:1
以直链烷烃同系物结构重复单元数值连续变化为模型假定,获得了描述直链烷烃同系物物理性质递变规律的数学表达式: P=a+bn(1/c),其中a、 b、 c均为常数, n为结构重复单元数值, P为直链烷烃同系物的物理性质。通过非线性回归分析,得到回归方程,结果表明直链烷烃同系物的物理性质与重复单元数值之间满足上述关系式,均显示优良的相关性。 相似文献
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Abstract A novel and facile synthesis of difunctional, aromatic vinyl ether analogs is reported. These materials, which are conveniently prepared by the condensation of 4-acetoxystyrene or 4-isopropenylphenyl acetate with α, ω-dihaloalkanes in the presence of base, can be cationically polymerized using diaryliodonium or triarylsulfonium salts as photoinitiators to produce crosslinked polymers. Relative reactivities of the monomers toward cationic polymerization were studied using differential scanning photocalorimetry. The thermal stabilities of the polymers resulting from the photopolymerization of the difunctional, aromatic vinyl ether analogs were studied using thermogravimetric analysis. 相似文献
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将直链烷烃分子看成是一个多自由度振动系统,用机械振动理论中的传递矩阵法计算了C2~C32直链烷烃的固有频率,分析了固有频率随化合物结构单元的变化规律.发现各阶固有频率中的基频与直链烷烃的结构型性质呈现出优良的相关性,用各阶固有频率之和表示的总频与直链烷烃的加和型性质也呈现出优艮的相关性,将两者组合后还能够反映直链烷烃的凝聚型性质的变化规律.在此基础上建立了直链烷烃的物化性能与基频和总频之间的定量相关模型.用该模型对直链烷烃的电离能、沸点、临界温度、临界压力、密度、粘度、标准生成焓、离子标准生成焓、常压热容、折光指数等10种不同类型性质的实验数据进行回归分析,相关系数均大于0.999. 相似文献
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高熔点蜡中正、异构烷烃碳数分布的高温气相色谱法 总被引:3,自引:0,他引:3
选用高温气相色谱仪HP5890Ⅱ分析高熔点蜡可达到C_(55)左右,将每个碳数中的正、异构烷烃完全分离,数据经BASIC程序处理,得到分布直方图。分析速度快并可减少样品组分的歧化作用。 相似文献
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烷基桥联双二茂铁衍生物的取代基效应与电化学性质的研究 总被引:3,自引:0,他引:3
对烷基桥联双二茂铁衍生物的电化学特性进行了研究.结果表明,分子稳定构象对该类分子体系的茂铁基电化学行为具有决定性影响,即两个二茂铁与桥头碳的夹角越小,其分子中2个茂铁基之间相互作用越大,ΔEp值越大.此外,讨论了酰基对茂铁中心的电氧化作用的影响,酰基表现出较强的吸电子诱导效应. 相似文献
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Catalytic dehydrogenation of light alkanes can effectively produce olefins and hydrogen. Even though Pt and CrOx‐based catalysts are widely applied in industry, research to improve the activity and stability of these catalysts continued. This review summarizes important achievements obtained in recent years, focusing on the development of supports, promoters and preparation methods of Pt and CrOx‐based catalysts, which mainly aimed to improve the dispersion of the active species and to enhance coke resistance. Furthermore, the high cost of Pt‐based catalysts and environmental problems encountered with CrOx‐based catalysts have spurred the development of alternative catalysts. The dehydrogenation performances and characteristics of promising alternative VOx‐, modified Ni‐ and Sn‐based catalysts are also reviewed. Comparison with the catalytic reforming process of naphtha further probes the necessity of catalyst acidity in these two different processes. The choice of the dehydrogenation reactor is discussed, and future perspectives and research directions are indicated. 相似文献
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Abstract The Syn isomers (3b and 4b) of xylene-bridged cryptophane showed selective complexing abilities for 2,2-dimethylbutane, 3-methylpentane, 3,3-di-methylpentane and 3-ethylpentane among the investigated alkanes, although the Anti isomers (3a,4a,5a) did not complex with these alkanes. However, both the Anti-and Syn-isomers (2a and 2b) of the diethyleneoxy-bridged cryptophane showed selective complexing abilities for 2,2-dimethylbutane, 3,3-dimethylpentane, 2,2,3-trimethylbutane and 2,2,3,3-terramethybutane among the investigated alkanes. 相似文献
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Carl R. Kemnitz Prof. Joel L. Mackey Mark J. Loewen Julie L. Hargrove Joshua L. Lewis Whitney E. Hawkins Adam F. Nielsen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(23):6942-6949
The potential origins of stability in branched alkanes are investigated, paying close attention to two recent hypotheses: geminal steric repulsion and protobranching. All alkane isomers through C6H14 along with heptane and octane were investigated at the MPW1B95/6‐311++G(d,p) level. Their geminal steric repulsion, total steric repulsion, and orbital interactions were evaluated by using natural bond orbital analysis. All measures of steric repulsion fail to explain the stability of branched alkanes. The extra stability of branched alkanes and protobranching, in general, is tied to stabilizing geminal σ→σ* delocalization, particularly of the type that involves adjacent C? C bonds and, thus, preferentially stabilizes branched alkanes. This picture is corroborated by valence bond calculations that attribute the effect to additional ionic structures (e.g., CH3+ :CH2 :CH3? and CH3:? CH2: CH3+ for propane) that are not possible without protobranching. 相似文献
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《Physics and Chemistry of Liquids》2012,50(2):255-266
Abstract The acoustic nonlinearity parameter B/A along with intermediate quantities such as the pressure derivative of sound speed and the phase shift were measured in 8 linear alkanes and a series of four isomers of hexane. The influences of temperature and chain length on these quantities were revealed. It was found that the phase shift parameter is more sensitive to molecular structure and temperature than B/A and that the pressure derivative of sound speed. 相似文献
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Selective Catalytic Transfer Dehydrogenation of Alkanes and Heterocycles by an Iridium Pincer Complex 下载免费PDF全文
Wubing Yao Yuxuan Zhang Xiangqing Jia Prof. Dr. Zheng Huang 《Angewandte Chemie (International ed. in English)》2014,53(5):1390-1394
Catalytic alkane dehydrogenation is a reaction with tremendous potential for application. We describe a highly active PSCOP‐pincer iridium catalyst for transfer dehydrogenation of cyclic and linear alkanes. The dehydrogenation of linear alkanes occurs under relatively mild conditions with high regioselectivity for α‐olefin formation. In addition, the catalyst system is very effective in the dehydrogenation of heterocycles to form heteroarenes and olefinic products. 相似文献
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Salomé Mielke Dr. Wasim Abuillan Dr. Mariam Veschgini Dr. Xianhe Liu Dr. Oleg Konovalov Prof. Dr. Marie Pierre Krafft Prof. Dr. Motomu Tanaka 《Chemphyschem》2019,20(13):1698-1705
Abstract : Semifluorinated alkanes FnHm self-assemble into nanometer-sized surface micelles at the air-water interface. In this study, we investigated how an atmosphere enriched with perfluorohexane (PFH) influences the interfacial viscoelasticity and structural order of a monolayer of FnHm by the combination of dilational rheology and grazing-incidence small-angle X-ray scattering (GISAXS). The monolayers behaved predominantly elastic which can be attributed to the strong dipole repulsions of the surface domains. Enrichment of the atmosphere with PFH lead to an increase of the compressibility and a decrease of the elastic modulus without altering the structural ordering of the FnHm molecules into highly correlated nanodomains, suggesting the adsorption of PFH molecules to the free spaces between the domains. The capability of FnHm domains to retain the structural integrity in the presence of PFH gas is promising for the fabrication of stable microbubbles for sonographic imaging. 相似文献
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Zoua Pa Vang Samuel J. Hintzsche Prof. Dr. Joseph R. Clark 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(39):9988-10000
Increasing demand for deuterium-labeled organic molecules has spurred a renewed interest in selective methods for deuterium installation. Catalytic transfer deuteration and transfer hydrodeuteration are emerging as powerful techniques for the selective incorporation of deuterium into small molecules. These reactions not only obviate the use of D2 gas and pressurized reaction setups but provide new opportunities for selectively installing deuterium into small molecules. Commercial or readily synthesized deuterium donors are typically employed as easy-to-handle reagents for transfer deuteration and hydrodeuteration reactions. In this minireview, recent advances in the catalytic transfer deuteration and hydrodeuteration of alkenes and alkynes for the selective synthesis of deuterated alkanes will be discussed. 相似文献
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Enzymatic Electrosynthesis of Alkanes by Bioelectrocatalytic Decarbonylation of Fatty Aldehydes 下载免费PDF全文
Dr. Sofiene Abdellaoui Dr. Florika C. Macazo Rong Cai Dr. Antonio L. De Lacey Dr. Marcos Pita Prof. Shelley D. Minteer 《Angewandte Chemie (International ed. in English)》2018,57(9):2404-2408
An enzymatic electrosynthesis system was created by combining an aldehyde deformylating oxygenase (ADO) from cyanobacteria that catalyzes the decarbonylation of fatty aldehydes to alkanes and formic acid with an electrochemical interface. This system is able to produce a range of alkanes (octane to propane) from aldehydes and alcohols. The combination of this bioelectrochemical system with a hydrogenase bioanode yields a H2/heptanal enzymatic fuel cell (EFC) able to simultaneously generate electrical energy with a maximum current density of 25 μA cm?2 at 0.6 V and produce hexane with a faradaic efficiency of 24 %. 相似文献