Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amou...Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amount of modifier, initial concentration of reactant, pressure and temperature on conversion and enantiometric excess in a stirred autoclave and the effects of the liquid velocity, gas velocity, modifier concentration and various catalytic beds in a trickle-bed reactor. The maximum optical yields were about 50% and 60% in the two types of reactors, respectively. It was assumed that the total hydrogenation rate included the reaction rates over the unmodified and modified active sites on platinum surface and a kinetic model, which fitted the experimental data well in autoclave, was obtained. A simplified plug-flow model was proposed to describe the bed average efficiency of trickle-bed reactor.展开更多
The title compound [UO2 （p-CH3C6H4SOC4H9）2 （NO3 ）2] is triclinicwith space group P1. a=8. 651 （3）, b=9. 097（2）, c=9. 621 （2） A;a=92. 29（1）, β=95. 97（3）, r=98. 25（3）, V=744. 1（3） A3, Z=1, Mr=786.41, ...The title compound [UO2 （p-CH3C6H4SOC4H9）2 （NO3 ）2] is triclinicwith space group P1. a=8. 651 （3）, b=9. 097（2）, c=9. 621 （2） A;a=92. 29（1）, β=95. 97（3）, r=98. 25（3）, V=744. 1（3） A3, Z=1, Mr=786.41, Dc=1. 425 g/cm3. u=5. 626 mm-1, F （000） =300. R=0. 030, Rw=0. 071 for 2917 reflectionswith I≥2（I）. Uranyl ion is coordinated to six oxygen atoms, of which two are fromtwo monodenate sulfoxides and the others from two nitrate groups. The coordinationPOlyhedron around U is a hexagonal bipyramid, the U atom is in the center of symmetry.展开更多
目的研究新型芳基异丙酸类化合物2-[4-(3-氧代丁基)苯基]丙酸(OPPA)与牛血清白蛋白(BSA)的相互作用。方法利用瞬态/稳态荧光光谱法和紫外光谱法,测算结合常数、结合位点数、热力学参数和分子的结合距离。结果在25℃下,反应平衡常数为3.9...目的研究新型芳基异丙酸类化合物2-[4-(3-氧代丁基)苯基]丙酸(OPPA)与牛血清白蛋白(BSA)的相互作用。方法利用瞬态/稳态荧光光谱法和紫外光谱法,测算结合常数、结合位点数、热力学参数和分子的结合距离。结果在25℃下,反应平衡常数为3.9×104L·mol-1,结合位点数为0.8;焓变为-16.29 k J·mol-1,熵变为205.04 J·mol-1·K-1,吉布斯自由能为-26.21 k J·mol-1;OPPA与BSA分子中色氨酸的最近距离为3.26 nm。结论 OPPA与BSA的相互作用为动态猝灭和静态猝灭的协同机理,OPPA与BSA的相互作用力主要是疏水相互作用力和静电作用力相互作用。展开更多
Co-or Mn-substituted LTL zeolites were hydrothermally synthesized by a novel organic-ligand-assisted method.XRD,UVVis DRS,XPS,and EPR techniques verified that the Co and Mn ions were incorporated into the zeolite fram...Co-or Mn-substituted LTL zeolites were hydrothermally synthesized by a novel organic-ligand-assisted method.XRD,UVVis DRS,XPS,and EPR techniques verified that the Co and Mn ions were incorporated into the zeolite framework.No organic species were retained in as-synthesized Co or Mn-LTL zeolites,which resulted in porous materials without calcination.In the oxidation of cyclohexane with tert-butyl hydroperoxide(TBHP),the Co-LTL and Mn-LTL gave a 40%–48%KA oil(cyclohexanone and cyclohexanol)yield as well as nearly 100%TBHP conversion under mild reaction conditions.The reactions were confirmed to be heterogeneous and to have proceeded catalytically.No loss of catalytic activity or leaching of metal active sites ions were observed during 4 reuses.展开更多
文摘Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amount of modifier, initial concentration of reactant, pressure and temperature on conversion and enantiometric excess in a stirred autoclave and the effects of the liquid velocity, gas velocity, modifier concentration and various catalytic beds in a trickle-bed reactor. The maximum optical yields were about 50% and 60% in the two types of reactors, respectively. It was assumed that the total hydrogenation rate included the reaction rates over the unmodified and modified active sites on platinum surface and a kinetic model, which fitted the experimental data well in autoclave, was obtained. A simplified plug-flow model was proposed to describe the bed average efficiency of trickle-bed reactor.
文摘The title compound [UO2 （p-CH3C6H4SOC4H9）2 （NO3 ）2] is triclinicwith space group P1. a=8. 651 （3）, b=9. 097（2）, c=9. 621 （2） A;a=92. 29（1）, β=95. 97（3）, r=98. 25（3）, V=744. 1（3） A3, Z=1, Mr=786.41, Dc=1. 425 g/cm3. u=5. 626 mm-1, F （000） =300. R=0. 030, Rw=0. 071 for 2917 reflectionswith I≥2（I）. Uranyl ion is coordinated to six oxygen atoms, of which two are fromtwo monodenate sulfoxides and the others from two nitrate groups. The coordinationPOlyhedron around U is a hexagonal bipyramid, the U atom is in the center of symmetry.
文摘目的研究新型芳基异丙酸类化合物2-[4-(3-氧代丁基)苯基]丙酸(OPPA)与牛血清白蛋白(BSA)的相互作用。方法利用瞬态/稳态荧光光谱法和紫外光谱法,测算结合常数、结合位点数、热力学参数和分子的结合距离。结果在25℃下,反应平衡常数为3.9×104L·mol-1,结合位点数为0.8;焓变为-16.29 k J·mol-1,熵变为205.04 J·mol-1·K-1,吉布斯自由能为-26.21 k J·mol-1;OPPA与BSA分子中色氨酸的最近距离为3.26 nm。结论 OPPA与BSA的相互作用为动态猝灭和静态猝灭的协同机理,OPPA与BSA的相互作用力主要是疏水相互作用力和静电作用力相互作用。
基金supported by the National Natural Science Foundation of China(21373089,U1162102)the PhD Programs Foundation of the Ministry of Education(2012007613000)+1 种基金the National Key Technology R&D Program(2012BAE05B02)the Shanghai Leading Academic Discipline Project(B409)
文摘Co-or Mn-substituted LTL zeolites were hydrothermally synthesized by a novel organic-ligand-assisted method.XRD,UVVis DRS,XPS,and EPR techniques verified that the Co and Mn ions were incorporated into the zeolite framework.No organic species were retained in as-synthesized Co or Mn-LTL zeolites,which resulted in porous materials without calcination.In the oxidation of cyclohexane with tert-butyl hydroperoxide(TBHP),the Co-LTL and Mn-LTL gave a 40%–48%KA oil(cyclohexanone and cyclohexanol)yield as well as nearly 100%TBHP conversion under mild reaction conditions.The reactions were confirmed to be heterogeneous and to have proceeded catalytically.No loss of catalytic activity or leaching of metal active sites ions were observed during 4 reuses.
