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| 1 | Hydrocracking diversity in n-dodecane isomerization on Pt/ZSM-22 and Pt/ZSM-23 catalysts and their catalytic performance for hydrodewaxing of lube base oil显示文摘Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that the Pt/ZSM-23 catalyst preferred to crack the C-C bond near the middle of n-dodecane chain,while the Pt/ZSM-22 catalyst was favorable for breaking the carbon chain near the end of n-dodecane.As a result,more than 2%of light products(gas plus naphtha)and3%more of heavy lube base oil with low-pour point and high viscosity index were produced on Pt/ZSM-22 than those on Pt/ZSM-23 while using the heavy waxy vacuum distillate oil as feedstock. | Shan-Bin Gao Zhen Zhao Xue-Feng Lu Ke-Bin Chi Ai-Jun Duan Yan-Feng Liu Xiang-Bin Meng Ming-Wei Tan Hong-Yue Yu Yu-Ge Shen Meng-Chen Li | 2020 | Petroleum Science2020，17，6： | 6 |
| 2 | Novel endo-to exo-isomerization of dicyclopentadiene显示文摘Endo-dicyclopentadiene was isomerized to exo-isomer by thermal treatment at evaluated temperature and pressure. The reaction temperature and pressure are key factors for this novel isomerization. This result may have great potential for practical application. | Xiang Wen Zhang Kai Jiang Qiang Jiang Ji Jun Zou Li Wang Zhen Tao Mi | 2007 | Chinese Chemical Letters2007，18，6： | 5 |
| 3 | Enhancement of Bio-based para-Xylene Selectivity in Catalytic Fast Pyrolysis of Cellulose Using a Surface-modified Mg/P/HZSM-5 Catalyst显示文摘With the growing consumption of oil, the production of /?-xylene(PX) from renewable biomass has gained significant attention recently. This work demonstrated that cellulose, a main component in lignocellulosic biomass, was directly converted into PX over the Mg/P surface-modified zeolites. The catalysts modified by the incorporation of P2O5 and MgO into HZSM-5(HZ) promoted the isomerization of zw-/o-xylenes to p-xylene. The PX selectivity was greatly enhanced using the modified zeolites due to the deactivation of external surface and the adjustment of pore entrance. In addition, the addition of methanol to cellulose was beneficial to increase the selectivity of xylenes due to the alkylation reactions and the Diels-Alder reactions between cellulose-derived furans and methanol-derived olefins. The highest PX yield of 10.7%(molar fraction) with a high PX selectivity in xylenes(97.1%) was obtained over the 10%Mg/5%P/HZ catalyst. The reaction pathway for the formation ofp-xylene was addressed according to the study of the key reactions and the characterization of catalysts. | WANG Yulan FAN Minghui ZHU Lijuan WANG Shengfei HE Yuting LI Quanxin | 2019 | Chemical Research in Chinese Universities2019，35，3： | 4 |
| 4 | Influence of the preparation method on the catalytic activity of Mg-Al hydrotalcites as solid base catalysts显示文摘Mg-Al hydrotalcites were synthesized using different preparation methods(a co-precipitation method, a urea method, and a simple one) to analyze their effect on the catalytic activity of these solid base catalysts. The method strongly affected the structure of their layers(e.g., the growth and stacking of the layers, and the type of intercalated anions) and, accordingly, their catalytic activity. The Mg-Al hydrotalcite prepared by co-precipitation showed the best catalytic performance in the isomerization of glucose into fructose, due to the small crystallite size and sand rose morphology enhancing the exposure of surface active sites to reactants. | Sungjae Park Dahye Kwon Ji Yeon Kang Ji Chul Jung | 2019 | Green Energy & Environment2019，4，3： | 4 |
| 5 | Structures and stabilities of HPO_2 isomers显示文摘The potential energy surface of HPO2 system including eight isomers and twelve transition states is predicated at MP2/6-311++G(d, p) and QCISD(t)/6-311++G(3df,2p)(single-point) levels of theory. On the potential energy surface, cis-HOPO(E1) is found to be thermodynamically and kinetically most stable isomer followed by trans-HOPO(E2) and HPO(O)(C2v, E3) at 10.99 and 48.36 kJ/mol higher, respectively. Based on the potential energy surface, only E1 and E3 are thermodynamically stable isomers, and should be experimentally observable. The products cis-HPOO(E5) and frans-HPOO(E6) in the first-step reaction of HP with O2 can isomerize into isomer E1 that has higher stability. The reaction of OH with PO will directly lead to the formation of isomer E1. The computed results are well consistent with the previous experimental studies. | 于海涛 黄旭日 池玉娟 李泽生 傅宏刚 孙家钟 | 2002 | Science China Chemistry2002，45，1： | 3 |
| 6 | Low Sulfur Low Olefin Gasoline Production by RIDOS Technology显示文摘By analysis of the component and structure of a real high olefinic FCC naphtha, a technology of deep desulfurization and olefin saturation with minimal octane loss is developed, which is named RIDOS. The multi functions of RIDOS technology are achieved by using a series of new catalysts, which show the good feed adaptability and operation flexibility. The results of the first commercial RIDOS unit showed that an ultra low sulfur (<10 μg/g), low olefin(<20%) gasoline was produced, while the road octane number lost only 1.3 unit. RIDOS technology provides the possibility for producing the clean fuels meeting most strict specifications. | Li Dadong 1, Shi Yahua 1, Yang Qingyu 2 (1. Research Institute of Petroleum Processing, SINOPEC, Beijing 100083 2. Yanshan Petrochemical Company, SINOPEC, Beijing 102503) | 2003 | 工程科学(英文版)2003，1，2： | 3 |
| 7 | Isomerization of linear C5–C7 over Pt loaded on protonated fibrous silica@Y zeolite(Pt/HSi@Y)显示文摘A novel fibrous silica Y zeolite (HSi@Y) loaded with Pt has been studied based on its ability to produce protonic acid sites originating from molecular hydrogen. The Pt/HSi@Y was prepared using seed assisted crystallization followed by protonation and Pt-loading. The product formed had a spherical morphology with bicontinuous lamellar with a diameter in the range of 500-700 nm. The catalytic activity of the Pt/HSi@Y has been assessed based on light linear alkane (C5-C7) isomerization in a micro-catalytic pulse reactor at 423-623 K. A pyridine IR study confirmed that the introduction of fibrous silica on Y zeolite increased the Lewis acid sites corresponding with the formation of extra-framework Al which led to the generation of more protonic acid sites. A hydrogen adsorbed IR study showed that the protonic acid sites which act as active sites in the isomerization were formed via dissociative-adsorption of molecular hydrogen releasing electrons to the nearby Lewis acid sites. Thus, it is suggested that the presence of Pt and HSi@Y with a high number of Lewis acid as well as weak Bronsted acid sites improved the activity and stability in C5, C6 and C7 isomerization via hydrogen spill-over mechanism. | S.Triwahyono A.A.Jalil S.M.Izan N.S.Jamari N.A.A.Fatah | 2019 | Journal of Energy Chemistry2019，28，10： | 3 |
| 8 | Structures and stabilities of HPS_2 isomers显示文摘The potential energy surface of HPS2 system containing nine isomers and fifteen transition states is obtained at MP2/6-311++G(d, p) and QCISD(t)/6-311++G(3df, 2p)(single-point) levels. On the potential energy surface, the lowest-lying frans-HSPS(EI) is found to be thermodynami-cally the most stable isomer followed by cis-HSPS(E2) and HP(S)S(C2v, E3) at 3.43 and 14.17 kJ/mol higher, respectively. The computed results show that species E1, E2, E3, stereo HP(S)S(Cs, E4) with PSS three-membered ring, isomers trans-HPSS(E5) and cis-HPSS(E6) which coexist with E4 are kinetically stable isomers. The products E6 and E5 in the reaction of HP with S2 can be isomerized into higher kinetic stable isomer E4 with 65.75 and 71.73 kJ/mol reaction barrier height, respectively. The predicated results may correct the possible inaccurate conclusion in that the product was experimentally assigned as isomer cis-HPSS(E6). | 于海涛 黄旭日 李泽生 池玉娟 傅宏刚 孙家钟 | 2002 | Science China Chemistry2002，45，3： | 2 |
| 9 | Study on the pinene isomerization catalyzed by TiM显示文摘The isomerization reaction of pinene is one of the most important chemical reactions in the deep processing of pinene. The purpose of this study is to improve the performance of the metatitanic acid by composite. The composite metatitanic acid catalyst TiM was prepared by adding Mn elements in the preparation process. The catalytic performance of TiM was evaluated. Comparison of TiM and metatitanic acid catalyst(Ti-FGP), the reaction rate of TiM catalyst was faster, and after the reaction, the yield of camphene and tricyclene increased about 1%. The catalysts were characterized by an SEM, FT-IR and laser particle size analyzer. The results show that the pinene isomerization reaction requires the synergistic action of the Br?nsted acid and Lewis acid.Br?nsted acid has great influence on the activity of catalyst, and Lewis acid has a great influence on the selectivity of the catalyst. The structure and morphology of the catalyst have a certain effect on the selectivity of pinene isomerization reaction. | Jionghua Xiang Zhenghong Luo | 2018 | Chinese Journal of Chemical Engineering2018，26，12： | 2 |
| 10 | Structural isomer and high-yield of Pt1Ag28 nanoduster via one-pot chemical wet method显示文摘In order to understand the structure-property correlation and explore the application of metal nanoclusters, it is important and intriguing to determine their crystal structure and obtain high-yield. At the same time, this is also a challenge in nanoscience and technology. Here, we report the highly efficient synthesis of Pt1Ag28 nanocluster via one-pot chemical wet method. The crystal structure of Pt1Ag28 nanocluster was determined by X-ray crystallography to be a face centered cubic (FCC) kernel. This novel structure is the structural isomerization of Pt1Ag28 nanocluster reported before. This phenomenon is first discovered in the synthesis of alloy nanoclusters. In addition, Pt1Ag28 nanocluster has high yield and exhibits potential optics in the near infrared (NIR) fluorescent imaging. The time-dependent density functional theory (TD-DFT) calculation implied that the optical property of Pt1Ag28 was sensitive to its structure. This work provides a simple method to synthesize alloy nanoclusters with structural isomerization. | Xinzhang Lin Chao Liu Keju Sun Ren'an Wu Xuemei Fu Jiahui Huang | 2019 | Nano Research2019，12，2： | 1 |
| 11 | Isomeric structures, isomerization and decomposition of silylenoids H2SiMX(MX=KF,KCl LiBr,NaBr and KBr)显示文摘The isomeric structures,isomerization and decomposition of silylenoids H2SiMX (MX= KF,KCI,LiBr,NaBr and KBr) have been investigated by 06 initio molecular orbital theory.These silylenoids have four kinds of very similar equilibrium structures.The three-membered ring and p-complex structures should be stable and experimentally detectable.The lifetime of o-complex and tetrahedral structures would be very short and experimentally undetectable. | Feng, DC Feng, SY Deng, CH | 1995 | Chinese Journal of Chemistry1995，13，6： | 1 |
| 12 | Synthesis of benzyl O-(2,3,3'-tri-O-acetyl-β-D-apiofuranosyl)-(1→3)-2,4-di-O-benzoyl-α-D-xylopyranoside and its X-ray structure显示文摘The protected apiose-containing disaccharide, benzyl O-(2,3, 3’-tri-O-acetyl-β-D-apiofuranosyl)-( 1→3)-2, 4-di-O-benzoyl-α-D-xylopyranoside, was synthesized and its X-ray structure provided. | 朱向明 俞飚 惠永正 | 2000 | Chinese Journal of Chemistry2000，18，1： | 1 |
| 13 | The occurrence of vanadium in nature:its biogeochemical cycling and relationship with organic matter—a case study of the Early Cambrian black rocks of the Niutitang Formation,western Hunan,China显示文摘Vanadium in the black rocks has economic and environmental impacts.In sediments,it is broadly disseminated as a multivalent metal element mainly sensitive to redox settings.Globally in petroleum,it is considered an abundant component.Vanadium is an essential tool to determine the relationship of the Earth with extra-terrestrial bodies.In the Yangtze region,the black rocks of the Early Cambrian Niutitang Formation are highly enriched in the concentration of V,Co,Ni and Mo.These sediments are comprised of a high total organic carbon content,and the average concentration of vanadium is over 240 ppm.Here we discuss the mechanisms and conditions that were responsible for the accumulation of vanadium in these black sediments in the Yangtze region.The oxygenated ocean water is favorable for the dissolved vanadate species Ⅴ(Ⅴ).Therefore,in oxic ocean-water,it can be reduced by organic matters or by H_(2)S to vanadyl ions Ⅴ(Ⅳ),which can facilely be adsorbed to the tiny particles and finally deposit into the sediments with the settling of the particles.The presence of V_(2)O_(3) in the Niutitang Formation indicates the isomorphism state of vanadium existence in the clay minerals.Clays and pyrite are the most favorable mineral for vanadium enrichment.However,it is suggested the quartz of non-biogenic origin might be unfavorable for vanadium enrichment.Vanadium is mainly derived from the diagenetic transformation of its precursor(porphyrin pigments and chlorophyll)from the organism.During the Early Cambrian period,the massive transgression in the sea level created a favorable environment for organisms to survive.Additionally,the hydrothermal activities brought massive nutrient supply in the form of vanadium and other metal elements from the deep Earth.These creatures consumed the vanadium-rich nutrients,which became a part of their bodies in the form of hard and soft parts.Later on,when these organisms died and were submerged in the sediments.After the diagenetic actions,this vanadium became a part of these black sediments along with organic carbon.Therefore,these black rocks in the Yangtze region are enriched in vanadium and organic carbon.It is suggested the various processes such as adsorption,complexation,and reductions are the main factors responsible for the precipitation of dissolved vanadium into the organically rich sediments. | Rizwan Sarwar Awan Chenglin Liu Shangfeng Yang Yuping Wu Qibiao Zang Ashar Khan Guoxiong Li | 2021 | Acta Geochimica2021，40，6： | 1 |
| 14 | Kinetics and mechanistic study of n-alkane hydroisomerization reaction on Pt-doped g-alumina catalyst显示文摘The catalysts g-alumina(GA,the reference catalyst)and Pt doped g-alumina(PGA-s)were synthesized using a simple sol-gel technique,in which at first preparation of porous base(GA),then impregnation of platinum salt over the base and finally reduction of platinum in the surface of the support were done.These catalysts prepared in different mole ratios of Pt:Al as 2:1,1:1 and 1:2 are named as PGA-1,PGA-2 and PGA-3 respectively.The isomerization of n-alkanes(n-hexane,nheptane and n-octane)were investigated over the synthesized catalysts.The 2-methyl pentane(2-MP),2,2-dimethyl pentane(2,2-DMP)and 2,3-dimethyl hexane(2,3-DMH)are the major products of respective isomerization of n-hexane,n-heptane and n-octane,besides a small amount of other branched isomers are also produced.The product distribution is comparable to that reported for Pt based other catalysts.The optimal mole ratios of Pt:Al is 1:1(PGA-2)gives quite good catalytic activity for isomerization of n-alkane.Even through in reusability study,PGA-2 gives better performance than others.We have mainly focused on kinetic study,reaction mechanism behind isomerization and calculated the order of reactions and activation energies of the isomerization reactions in the present work. | Abhishek Dhar Rohit L.Vekariya Pushan Sharma | 2017 | Petroleum2017，3，4： | 1 |
| 15 | Rh-Catalyzed Kinetic Resolution-Based Enantioselective[4+2]-Cydoaddition-lsomerization of Allene-1,3-dienes显示文摘Main observation and conclusion The first example of Rh-catalyzed kinetic resolution of 1,3-disubstituted allene-1,3-dienes involving intramolecular[4+2]-cycloaddition has been developed.Followed by C=C isomerization,the reaction finally afforded aza-[4.3.0]bicyclic compounds with a very high en-antio-and E-selectivity.The mechanism has been unveiled by careful control experiments.The synthetic potentials of highly enanti-oenriched bicyclic products have also been demonstrated. | Anni Qin Qian Zhang Hui Qian Yulin Han Shengming Ma | 2021 | Chinese Journal of Chemistry2021，39，3： | 1 |
| 16 | THEORETICAL STUDIES ON THE STRUCTURES AND REACTIVITY OF SILYLENOIDS (Ⅰ)——STRUCTURES AND ISOMERIZATION OF SILYLENOID H_2SiLiCl显示文摘The structures of silylenoid H2SiLiCl have been studied by RHF/3-21G gradient method. Three equilibrium states and two isomerization transition states are located. The electronic energy, Mulliken populations, dipole moments and frontier molecular orbitals (FMO) of every structure and the isomeric barriers are also given and analyzed. Further single point calculations on the 3-21G optimum geometries were performed using 6-21G basis set. The calculations show that three-membered ring structure of H2SiLiCl is the most stable and detectable, and the 'classical' tetrahedral form is not the local minimum on the potential energy surface. | 冯圣玉 居冠之 邓从豪 | 1992 | Science China Chemistry1992，35，5： | 1 |
| 17 | Light-Responsive Polyblend Films with Reconfigurable Surface Micropatterns as Rewritable Information Storage Media显示文摘Stimulus-sensitive surfaces with tunable morphologies exhibit a wide range of applications in the fields of surface science and engineering.Herein,a cost-effective yet practical strategy is proposed to fabricate photo-sensitive patterning surface on film/substrate wrinkle system based on an azo-containing polyblend.By manipulating the stress field of the bilayer system globally and/or locally upon the stress relaxation triggered by the reversible cis-trans isomerization of the azobenzene,heating/cooling triggered surface wrinkles on the polyblend films could be tailor-made with visible-light-irradiation.Notably,upon selective photo-irradiation,bespoke surface patterns may be cyclically generated or eliminated,allowing these reconfigurable patterned polyblend surfaces to be used as rewritable information storage media for non-ink printing.The as-prepared photo-printed information patterns with high-resolution are shown to be rewritable for multiple cycles and legible for over 90 d in dark ambient conditions.This study not only provides a versatile strategy for flourishing the stimulus-sensitive systems,but also sheds light on the stress relaxation-triggered morphological evolution of the wrinkling polyblend films. | Jian Chen Xiaoyu Yang Jie Chen Umair Azhar Feiyan Chen Ruijie Zhu Chunhua Zhou Shichun Jiang Wei Wang Peiming Xu Chuanyong Zong | 2023 | Chinese Journal of Chemistry2023，41，3： | 1 |
| 18 | Mewing Polymers via Photoisomerization显示文摘Photoresponsive materials,which can adapt their states and shapes upon light irradiation,have attracted worldwide attention in the past decades.The development of azobenzene-containing polymers(azopolymers)opens up an avenue for controlling their properties and functions with light.These polymers show shape changes and mechanical responses under the stimulation of light via photoisomerization of azobenzene groups.Herein,this report focuses on the growing research on moving polymers via photoisomerization,including their moving mechanisms and various applications. | Yazhi Liu Shaodong Sun Si Wu | 2020 | Chinese Journal of Chemistry2020，38，9： | 1 |
| 19 | Triphenylphosphine-catalyzed isomerization of alkynyl ketones in aqueous solution显示文摘An efficient isomerization of alkynyl ketones to(E,E)-diene ketones was developed.The reaction catalyzed by 20 mol% triphenylphosphine in aqueous media gave the desired products in good yields. | Qing Fa Zhou Fei Yang Qing Xiang Guo Song Xue | 2007 | Chinese Chemical Letters2007，18，9： | 1 |
| 20 | Stability study on an anti-cancer drug 4-(3,5-bis(2-chlorobenzylidene)-4-oxo-piperidine-1-yl)-4-oxo-2-butenoic acid (CLEFMA) using a stabilityindicating HPLC method显示文摘CLEFMA, 4-(3,5-bis(2-chlorobenzylidene)-4-oxo-piperidine-1-yl)-4-oxo-2-butenoic acid, is a new chemical entity with anti-cancer and anti-inflammatory activities. Here, we report its stability in solution against stress conditions of exposure to acid/base, light, oxidant, high temperature, and plasma. The identity of the degradation products was ascertained by mass and proton nuclear magnetic resonance spectroscopy. To facilitate this study, we developed and validated a reverse phase high performance liquid chromatography method for detection of CLEFMA and its degradation. The method was linear over a range of 1–100 μg/m L; the accuracy and precision were within acceptable limits; it was stability-indicating as it successfully separated cis-/trans-isomers of CLEFMA as well as its degradation product. The major degradation product was produced from amide hydrolysis at maleic acid functionality caused by an acidic buffer, oxidant(3% hydrogen peroxide),or temperature stress(40–60 °C). The log k-p H profile showed that CLEFMA was most stable at neutral p H. In accelerated stability study we found that the shelf-life(T_(90%)) of CLEFMA at 25 °C and 4 °C was 45 days and220 days, respectively. Upon exposure to UV-light(365 nm), the normally prevalent trans-CLEFMA attained cis-configuration. This isomerization also involved the maleic acid moiety. CLEFMA was stable in plasma from which it could be efficiently extracted by an acetonitrile precipitation method. These results indicate that CLEFMA is sensitive to hydrolytic cleavage at its maleic acid moiety, and it is recommended that its samples should be stored under refrigerated and light-free conditions, and under inert environment. | Dhawal Raghuvanshi Gregory Nkepang Alamdar Hussain Hooman Yari Vibhudutta Awasthi | 2017 | Journal of Pharmaceutical Analysis2017，7，1： | 0 |
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