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Coordination polymers based on anthracene-and pyrene-derived ligands:Crystal structure,fluorescent property,and framework isomerization
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作者 HU Youbo LI Donggang +2 位作者 SUN Changhua LU Zhenzhong GU Songjun 《无机化学学报》 北大核心 2025年第8期1681-1688,共8页
Six coordination polymers based on 9,10-di(pyridine-4-yl)-anthracene(DPA)and 1,6-di(1H-imidazol-1-yl)pyrene(DIP)were obtained by solvothermal reactions.{[Zn(DPA)Cl_(2)]·DMF·2H_(2)O}n(1)and{[Zn_(1.5)(DPA)_(1.... Six coordination polymers based on 9,10-di(pyridine-4-yl)-anthracene(DPA)and 1,6-di(1H-imidazol-1-yl)pyrene(DIP)were obtained by solvothermal reactions.{[Zn(DPA)Cl_(2)]·DMF·2H_(2)O}n(1)and{[Zn_(1.5)(DPA)_(1.5)Cl_(3)]·5H_(2)O}n(2)are framework isomers,which both contain zigzag chains formed by DPA,Zn^(2+),and Cl-.The zigzag chains in 1 are further assembled by C—H…Cl interactions into layers,and these layers exhibit two different orientations,displaying a rare 2D to 3D interpenetration mode.The zigzag chains in 2 are parallelly arranged.{[Zn_(3)(DPA)_(3)Br_(6)]·2DMF·_(1.5)H_(2)O}n(3)is isostructural to 2.3 was obtained using ZnBr_(2)instead of ZnCl_(2).[M(DPA)(formate)_(2)(H_(2)O)_(2)]n[M=Co(4),Cu(5)]are isostructural,contain chain structures formed by DPA,Cu^(2+)/Co^(2+),and for-mate ions,which were formed in situ in the solvothermal reaction.{[Zn(DIP)_(2)Cl]ClO_(4)}n(6)contains a layer structure formed by DIP and Zn^(2+).Free DPA and DIP ligands exhibited high fluorescence at room temperature,and coordina-tion polymers 3 and 6 displayed enhanced fluorescent emissions. 展开更多
关键词 coordination polymer anthracene derivatives pyrene derivatives fluorescence framework isomerization
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Elucidating the catalytic role of lithium(Li)in the glucose-to-fructose isomerization over Li-C_(3)N_(4) catalyst at 60℃ in water
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作者 WANG Yuxuan GUO Fenfen +7 位作者 JIANG Zhicheng TU Youjing ZHANG Xingyu TANG Aoyi WANG Junxia LIANG Yuan YAN Lishi KONG Lingzhao 《燃料化学学报(中英文)》 北大核心 2025年第9期1373-1384,共12页
Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could ... Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could be employed as a starting material to prepare some other functional derivatives for improving the value of biomass resources.The isomerization of glucose to produce fructose is an important intermediate process during numerous high-value-added chemical preparations.Therefore,the development of efficient and selective catalysts for glucose isomerization is of great significance.Currently,glucose isomerase catalysts are limited by the harsh conditions required for microbial activity,which restricts further improvements in fructose yield.Additionally,heterogeneous Bronsted-base and Lewis-acid catalysts commonly employed in chemical isomerization methods often lead to the formation of undesirable by-products,resulting in reduced selectivity toward fructose.This study has demonstrated that lithium-loaded heterogeneous catalysts possess excellent isomerization capabilities under mild conditions.A highly efficient Li-C_(3)N_(4) catalyst was developed,achieving a fructose selectivity of 99.9% and a yield of 42.6% at 60℃ within 1.0 h-comparable to the performance of the enzymatic method.Characterization using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),proton nuclear magnetic resonance(^(1)H NMR),and inductively coupled plasma(ICP)analyses confirmed that lithium was stably incorporated into the g-C_(3)N_(4) framework through the formation of Li-N bonds.Further investigations using CO_(2) temperature-programmed desorption(CO_(2)-TPD),in situ Fourier-transform infrared spectroscopy(FT-IR)and 7Li magic angle spinning nuclear magnetic resonance(^(7)Li MAS NMR)indicated that the isomerization proceeded via a base-catalyzed mechanism.The Li species were found to interact with hydroxyl groups generated through hydrolysis and simultaneously coordinated with nitrogen atoms in the C_(3)N_(4) matrix,resulting in the formation of Li-N_(6)-H_(2)O active sites.These active sites facilitated the deprotonation of glucose to form an enolate intermediate,followed by a proton transfer step that generated fructose.This mechanism not only improved the efficiency of fructose production but also provided valuable insight into the catalytic role of lithium within the isomerization process. 展开更多
关键词 GLUCOSE FRUCTOSE isomerization hydrothermal catalysis Li-C_(3)N_(4)
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19.1%Efficiency PM6:Y6 based ternary organic solar cells enabled by isomerization engineering of A_(2)-A_(1)-D-A_(1)-A_(2)type vip molecules
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作者 Huijuan Ran Bingjie Zhou +6 位作者 Leyi Tang Kehui Wang Jia Yao Bo Xiao Yunfeng Xu Qing Guo Erjun Zhou 《Journal of Energy Chemistry》 2025年第9期577-583,I0015,共8页
In recent years,the ternary strategy of adding a vip molecule to the active layer has been proven to be effective for improving the performance of organic solar cells(OSCs).Isomerization engineering of the vip mol... In recent years,the ternary strategy of adding a vip molecule to the active layer has been proven to be effective for improving the performance of organic solar cells(OSCs).Isomerization engineering of the vip molecule is a simple method to increase the amount of promising material,but there are only limited reports,and the structure-property relationships are still unclear.In this work,we synthesized three isomers named BTA5-F-o,BTA5-F-m,and BTA5-F-p,with different fluorine substitution positions,to study the influence of isomerization on the photovoltaic performance.After introducing them as the third components to the classic host system PM6:Y6,all three ternary devices showed improved power conversion efficiency(PCEs)compared to the binary system(PCE of 17.46%).The ternary OSCs based on BTA5-F-o achieved a champion PCE of 19.11%,while BTA5-F-m and BTA5-F-p realized PCEs of 18.65%and 18.45%,respectively.Mechanism studies have shown that the dipole moment of the BTA5-F-o end group is closer to that of the Y6 end group,despite the three isomers with almost identical energy levels and optical properties.It is indicated that the electron attraction ability of BTA5-F-o best matches that of Y6,which leads to the higher charge mobility,less charge recombination,and stronger exciton dissociation and extraction ability in the ternary blend system.This study suggests that rationally adjusting the position of substituents in the terminal group can be an effective way to construct nonfullerene vip acceptors to achieve highly efficient ternary OSCs. 展开更多
关键词 Ternary organic solar cells vip molecules isomerization Nonfullerene acceptors Charge transfer
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Hydrodesulfurization and isomerization performance of model FCC naphtha over sulfided Co(Ni)-Mo/Y catalysts
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作者 Dongyang Liu Guohao Zhang +4 位作者 Xinsheng Kang Wenzhe Wu Liang Zhao Jinsen Gao Chunming Xu 《Chinese Journal of Chemical Engineering》 2025年第1期185-194,共10页
The process of deep hydrodesulfurization(HDS)in gasoline typically results in the saturation of olefins,leading to significant reductions in octane number.In this work,Y-supported Co(Ni)-Mo catalysts that with differe... The process of deep hydrodesulfurization(HDS)in gasoline typically results in the saturation of olefins,leading to significant reductions in octane number.In this work,Y-supported Co(Ni)-Mo catalysts that with different Ni-Co content were prepared by the incipient wetness impregnation method,the structure and properties were characterized and analyzed using HRTEM,XPS,H_(2)-TPR,and NH_(3)-TPD.The isomerization of 1-hexene and 1-octene as well as the HDS of thiophene were studied by using model FCC naphtha.The incorporation of Ni was found to enhance the number of MoS_(2) stacking layers,thereby improving the degree of sulfurization in Mo and subsequently increasing the desulfurization rate,with a maximum achieved desulfurization rate of 94.7%.When employing a Ni/Co ratio of 3:2,optimal synergy between Ni and Co is achieved,resulting in a greater presence of multi-layer stacked II-Co(Ni)MoS active phases.Additionally,appropriate Brønsted acidity levels are maintained to facilitate efficient olefin isomerization while preserving high HDS activity.As a result,the current isomerization yield stands at 58.2%(mass).These understandings shed light on the development of highly HDS and olefin isomerization catalysts. 展开更多
关键词 HYDRODESULFURIZATION isomerization Co(Ni)-Mo/Y Co(Ni)MoS
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Trans-cis isomerization of 4-(2-(9-anthryl)vinyl) pyridine.Molecular structures and ~1H NMR kinetic studies
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作者 蔡雅然 黄维扬 黄永德 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1999年第2期100-107,共0页
Both cis- and trans-isomers of 4-(2-(9-anthryl) vinyl) pyridine were isolated and their molecular structures established by X-ray crystallographic method. Variable temperature 1H NMR spectroscopy was used to study the... Both cis- and trans-isomers of 4-(2-(9-anthryl) vinyl) pyridine were isolated and their molecular structures established by X-ray crystallographic method. Variable temperature 1H NMR spectroscopy was used to study the trans to cis isomerization of the title compound. The kinetic study of the reaction was based on the ratio of the NMR integration heights in toluene-d8 of the double doublet due to the cis-isomer at δ 8.51 to that of the multiplet at δ 8. 15 which was kept constant during the whole experiment. The isomerization process was found to be first order and the Arrhenius activation parameters E8, ln A, Δ H≠ and ΔS≠ were calculated as 27.84 kJ/mol, 6.71, 25.23 kJ/mol and ?197.89 J/(K·mol), respectively. Besides, conformational analyses of both compounds based on molecular modeling were carried out and the results were used to compare with the experimental data. 展开更多
关键词 isomerization ANTHRACENES KINETICS X-ray crystal structures
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Co-Harvest Phase-Change Enthalpy and Isomerization Energy for High-Energy Heat Output by Controlling Crystallization of Alkyl-Grafted Azobenzene Molecules 被引量:2
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作者 Jian Gao Yiyu Feng +6 位作者 Wenyu Fang Hui Wang Jing Ge Xiaoyu Yang Huitao Yu Mengmeng Qin Wei Feng 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第3期415-424,共10页
Photoisomerization-induced phase change are important for co-harvesting the latent heat and isomerization energy of azobenzene molecules.Chemically optimizing heat output and energy delivery at alternating temperature... Photoisomerization-induced phase change are important for co-harvesting the latent heat and isomerization energy of azobenzene molecules.Chemically optimizing heat output and energy delivery at alternating temperatures are challenging because of the differences in crystallizability and isomerization.This article reports two series of asymmetrically alkyl-grafted azobenzene(Azo-g),with and without a methyl group,that have an optically triggered phase change.Three exothermic modes were designed to utilize crystallization enthalpy(△H_(c))and photothermal(isomerization)energy(△H_(p))at different temperatures determined by the crystallization.Azo-g has high heat output(275-303 J g^(-1))by synchronously releasing△H_(c)and△H_(p)over a wide temperature range(-79℃to 25℃).We fabricated a new distributed energy utilization and delivery system to realize a temperature increase of 6.6℃at a temperature of-8℃.The findings offer insight into selective utilization of latent heat and isomerization energy by molecular optimization of crystallization and isomerization processes. 展开更多
关键词 crystallizability distributed energy utilization system energy density exothermic modes isomerization
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Cobalt-Catalyzed Regio-and Stereoselective Isomerization of Terminal Alkenes to trans-2-Alkenes 被引量:1
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作者 Du Jiayan Liu Juntao +1 位作者 Liu Guixia Huang Zheng 《有机化学》 SCIE CAS CSCD 北大核心 2024年第9期2889-2897,共9页
An efficient and E-selective monoisomerization of 1-alkenes is developed with a bis(phosphine)-based PCP-type Co complex as the catalyst.The protocol provides an atom-economical approach to trans-2-alkenes with high r... An efficient and E-selective monoisomerization of 1-alkenes is developed with a bis(phosphine)-based PCP-type Co complex as the catalyst.The protocol provides an atom-economical approach to trans-2-alkenes with high regio-and stereoselectivity,featuring mild conditions and wide substrate scope.Mechanistic investigation supports a cobalt-hydride pathway involving reversible alkene insertion/β-H elimination,and the step ofβ-H elimination at the allylic position is likely the rate-determining step. 展开更多
关键词 cobalt catalysis ALKENES isomerization regioselectivity STEREOSELECTIVITY
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Mechanisms of isomerization and hydration reactions of typicalβ-diketone at the air-droplet interface 被引量:1
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作者 Yuemeng Ji Weiyong Luo +5 位作者 Qiuju Shi Xiaohui Ma Ziqi Wu Weina Zhang Yanpeng Gao Taicheng An 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第7期225-234,共10页
Acetylacetone(AcAc)is a typical class ofβ-diketones with broad industrial applications due to the property of the keto-enol isomers,but its isomerization and chemical reactions at the air-droplet interface are still ... Acetylacetone(AcAc)is a typical class ofβ-diketones with broad industrial applications due to the property of the keto-enol isomers,but its isomerization and chemical reactions at the air-droplet interface are still unclear.Hence,using combined molecular dynamics and quantum chemistry methods,the heterogeneous chemistry of AcAc at the air-droplet interface was investigated,including the attraction of AcAc isomers by the droplets,the distribution of isomers at the air-droplet interface,and the hydration reactions of isomers at the air-droplet interface.The results reveal that the preferential orientation of two AcAc isomers(keto-and enol-AcAc)to accumulate and accommodate at the acidic air-droplet interface.The isomerization of two AcAc isomers at the acidic air-droplet interface is more favorable than that at the neutral air-droplet interface because the“water bridge”structure is destroyed by H_(3)O^(+),especially for the isomerization from keto-Ac Ac to enol-AcAc.At the acidic air-droplet interface,the carbonyl or hydroxyl O-atoms of two AcAc isomers display an energetical preference to hydration.Keto-diol is the dominant products to accumulate at the air-droplet interface,and excessive keto-diol can enter the droplet interior to engage in the oligomerization.The photooxidation reaction of AcAc will increase the acidity of the air-droplet interface,which indirectly facilitate the uptake and formation of more keto-diol.Our results provide an insight into the heterogeneous chemistry ofβ-diketones and their influence on the environment. 展开更多
关键词 ACETYLACETONE Air-droplet interface Theoretical simulation isomerization Hydration reaction mechanism
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Li-promoted C_(3)N_(4) catalyst for efficient isomerization of glucose into fructose at 50℃ in water 被引量:2
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作者 Wang Liu Yanfei Zhang +5 位作者 Mengya Sun Xinpeng Zhao Shenggang Li Xinqing Chen Liangshu Zhong Lingzhao Kong 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第9期1419-1426,共8页
Efficient and selective glucose-to-fructose isomerization is a crucial step for production of oxygenated chemicals derived from sugars,which is usually catalyzed by base or Lewis acid heterogeneous catalyst.However,hi... Efficient and selective glucose-to-fructose isomerization is a crucial step for production of oxygenated chemicals derived from sugars,which is usually catalyzed by base or Lewis acid heterogeneous catalyst.However,high yield and selectivity of fructose cannot be simultaneously obtained under mild conditions which hamper the scale of application compared with enzymatic catalysis.Herein,a Li-promoted C_(3)N_(4) catalyst was exploited which afforded an excellent fructose yield(40.3 wt%)and selectivity(99.5%)from glucose in water at 50℃,attributed to the formation of stable Li–N bond to strengthen the basic sites of catalysts.Furthermore,the so-formed N_(6)–Li–H_(2)O active site on Li–C_(3)N_(4) catalyst in aqueous phase changes the local electronic structure and strengthens the deprotonation process during glucose isomerization into fructose.The superior catalytic performance which is comparable to biological pathway suggests promising applications of lithium containing heterogeneous catalyst in biomass refinery. 展开更多
关键词 GLUCOSE FRUCTOSE isomerization Li–C_(3)N_(4) Density functional theory calculations
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Highly efficient isomerization of glucose to fructose over Sn-doped silica nanotube 被引量:1
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作者 Yajiao Cui Zhi Yang +5 位作者 Xiongtao Hu Shufei Yang Armin Rezayan Tianliang Lu Zhiyong Chen Yongsheng Zhang 《Resources Chemicals and Materials》 2024年第2期159-165,共7页
Isomerization of glucose to fructose is a fundamental and key intermediate process commonly included in the production of valuable chemicals from carbohydrates in biorefinery.Enhancement of fructose yield is a challen... Isomerization of glucose to fructose is a fundamental and key intermediate process commonly included in the production of valuable chemicals from carbohydrates in biorefinery.Enhancement of fructose yield is a challenge.In this work,Sn-doped silica nanotube(Sn-SNT)was developed as a highly efficient Lewis acid catalyst for the selective isomerization of glucose to fructose.Over Sn-SNT,69.1%fructose yield with 78.5%selectivity was obtained after reaction at 110◦C for 6 h.The sole presence of a large amount of Lewis acid sites in Sn-SNT without Brønsted acid site is one of the reasons for the high fructose yield and selectivity.Otherwise,high density of SiOH groups in Sn-SNT can ensure the presence of SiOH groups near the Sn sites,which is important for the isomerization of glucose to fructose,leading to the high fructose yield and selectivity.Furthermore,the Sn-SNT is recyclable. 展开更多
关键词 GLUCOSE FRUCTOSE Lewis acid isomerization
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Critical approaches in the catalytic transformation of sugar isomerization and epimerization after Fischer-History,challenges,and prospects
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作者 Da-Ming Gao Xun Zhang +5 位作者 Haichao Liu Hidemi Fujino Tingzhou Lei Fuan Sun Jie Zhu Taoli Huhe 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第3期435-453,共19页
The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and... The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and the synthesis of drugs.Nowadays,high-fructose corn syrup(HFCS)is industrially produced in more than 10 million tons annually using immobilized glucose isomerase.Some low-calorie saccharides such as tagatose and psicose,which are becoming popular sweeteners,have also been produced on a pilot scale in order to replace sucrose and HFCS.However,current catalysts and catalytic processes are still difficult to utilize in biomass conversion and also have strong substrate dependence in producing high-value,rare sugars.Considering the specific reaction properties of saccharides and catalysts,since the pioneering discovery by Fischer,various catalysts and catalytic systems have been discovered or developed in attempts to extend the reaction pathways,improve the reaction efficiency,and to potentially produce commercial products.In this review,we trace the history of sugar isomerization/epimerization reactions and summarize the important breakthroughs for each reaction as well as the difficulties that remain unresolved to date. 展开更多
关键词 Rare sugars isomerization KETONIZATION EPIMERIZATION Catalytic transformation
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Phase Patterning of Poly(oxime-ester)for Information Encryption by Photo-induced Isomerization
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作者 Yu-Fan Yang Yun Bai +1 位作者 Yi-Bao Li Chang-Fei He 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第10期1488-1494,I0010,共8页
Crystal polymers or liquid crystal elastomers undergo a phase transition that results in a change in the corresponding optical properties,which has the potential to be applied in areas such as information encryption a... Crystal polymers or liquid crystal elastomers undergo a phase transition that results in a change in the corresponding optical properties,which has the potential to be applied in areas such as information encryption and anti-counterfeiting.The utilization of these materials for patterning purposes requires different phase transition temperatures.However,once prepared,altering the phase transition temperature of them presents significant challenges.Herein,a poly(oxime-ester)(POE)network is developed to achieve high-resolution and multilevel patterning by photo-induced isomerization.The as-prepared POE exhibits the ability to transition from an opaque state to a transparent state under temperature stimuli,with the transition temperature and kinetics dependent on UV light exposure time.Thus,complex patterns and information can be encrypted through different selective regional exposure time and decrypted under specific temperature or cooling time.Furthermore,we illustrate an example of temporal communication,where cooling time or temperature serves as the encoded information.This research expands the application scope of advanced encryption materials,showcasing the potential of POE in dynamic information encryption and decryption processes. 展开更多
关键词 Poly(oxime-ester) isomerization Phase patterning Information encryption
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Developing a highly scalable synthetic strategy for 5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,b-dioxide(CL-18)and investigating the influence of crystal engineering and positional isomerization on its safety and laser ignition performance
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作者 Lei Yang Zhenqi Zhang +2 位作者 Wei Du Jinshan Li Qing Ma 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第11期13-21,共9页
5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,6-dioxide(CL-18)exhibits significant potential as an initiating explosive.However,its current synthesis process remains non-scalable due to low yields and ... 5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,6-dioxide(CL-18)exhibits significant potential as an initiating explosive.However,its current synthesis process remains non-scalable due to low yields and safety risks.In this study,we have developed a simple and safe synthetic route for CL-18.It was synthesized from 3,5-dihaloanisole in a four-step reaction with an overall yield exceeding 60%,surpassing all reported yields in the literature.Subsequently,recrystallization of CL-18 was successfully achieved by carefully selecting appropriate solvents and antisolvents to reduce its mechanical sensitivity.Ultimately,when DMF-ethanol was employed as the recrystallization solvent system,satisfactory product yield(>90%)and reduced mechanical sensitivity(IS=15 J;FS=216 N)were obtained.Additionally,CL-18 is derived from the rearrangement of oxygen atoms on i-CL-18 furoxan,and a comparative analysis of their physicochemical properties was conducted.The thermal stability of both compounds is similar,with onset decomposition temperatures recorded at 186 and 182℃respectively.Similarly,they exhibit 5 s breaking point temperatures of 236 and 237℃.Additionally,we present novel insights into the positional-isomerization-laser-ignition performance of CL-18 and its isomer i-CL-18 using laser irradiation for the first time.Remarkably,our findings demonstrate that i-CL-18 exhibits enhanced laser sensitivity,as it can be directly ignited by a 1064 nm wavelength laser,whereas CL-18 lacks this characteristic. 展开更多
关键词 Initiating explosive Synthetic method Crystal engineering Positional isomerization Laser ignition
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Crown aldoxime ethers:Their synthesis,structure,acid-catalyzed/photo-induced isomerization and adjustable vip binding
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作者 Yulin Mao Jingyu Ma +3 位作者 Jiecheng Ji Yuliang Wang Wanhua Wu Cheng Yang 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第11期318-322,共5页
A series of novel crown aldoxime ethers were synthesized,demonstrating notable thermal and hydrolysis stability.The showcased acid-catalyzed and photo-induced cis/trans isomerization,which enables orthogonal control o... A series of novel crown aldoxime ethers were synthesized,demonstrating notable thermal and hydrolysis stability.The showcased acid-catalyzed and photo-induced cis/trans isomerization,which enables orthogonal control over both vip complexation and the chiroptical effects of these crown aldoxime ethers,manifesting a regulation of complexation through isomerization at binding heteroatoms. 展开更多
关键词 Crown aldoxime ether Cis/trans isomerization PHOTOisomerization Chiroptical induction Orthogonal control
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Synthesis of Pt/PMA-MIL-101 Catalyst and Its Performance in n-Heptane Isomerization
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作者 Zhang Wei Guo Qiang +5 位作者 Wang Yingjun Suo Yanhua Lin Wenqiu Hu Tengyu Li Tong Liu Shetian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第3期63-72,共10页
Hydroisomerization of n-heptane is an efficient method for producing gasoline with a high octane number.The focus of this study was to find a highly efficient catalyst that could both promote the conversion of n-hepta... Hydroisomerization of n-heptane is an efficient method for producing gasoline with a high octane number.The focus of this study was to find a highly efficient catalyst that could both promote the conversion of n-heptane and inhibit the cracking side reaction.MIL-101(Cr)is a chromium-based metal-organic framework(MOF)with good hydrothermal stability,and exhibits a three-dimensional pore structure that is similar to that of zeolites.Using phosphomolybdic acid(PMA;H3PMo12O40·xH2O)can increase the number of Brønsted acid sites on MIL-101(Cr),which contributes to improving the catalytic performance during isomerization.In this study,0.4%Pt/PMA-MIL-101(Cr)catalyst was successfully crystallized at 220℃using a hydrothermal synthetic method.The results showed that the synthesized samples were mesoporousmicroporous composite materials with the typical octahedral structure,and the MIL-101(Cr)framework was not damaged following modification with PMA.It was found that 0.4%Pt30%PMA-MIL-101(Cr)exhibited the best performance for isomerization of n-heptane,with a conversion rate and selectivity at 260°C of 47.6%and 96.6%,respectively.After five hours of reaction,the conversion rate and selectivity of the catalyst remained above 38%and 80%,respectively. 展开更多
关键词 MIL-101(Cr) N-HEPTANE isomerization phosphomolybdic acid CATALYSIS
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Swelling,Interfacial Behavior,and Rheology of Soft Core-Shell Microgels Introducing Acid Isomer for pH-Temperature Dualresponsiveness
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作者 Li Zhang Xin-Rui Li +7 位作者 Xia-Hui Xiao Li-Dan Zhou Yu-Wei Zhu Jia-Yu Chen Hang Jiang Jie Han Wei Liu To Ngai 《Chinese Journal of Polymer Science》 2025年第5期745-755,共11页
In this study,a pair of dicarboxylic acids as cis-trans isomerism—citraconic acid(CA)and mesaconic acid(MA),was incorporated into polymeric networks of poly(N-isopropylacrylamide)(PNIPAM)-based core-shell microgels v... In this study,a pair of dicarboxylic acids as cis-trans isomerism—citraconic acid(CA)and mesaconic acid(MA),was incorporated into polymeric networks of poly(N-isopropylacrylamide)(PNIPAM)-based core-shell microgels via semi-batch precipitation polymerization.We demonstrated that the pH-temperature dual responsiveness of the core-shell microgels is highly correlated with the structure and position of the acid isomers.Both the cis-trans molecular structure and the crosslinking position of the dicarboxylic acids significantly influenced the hydration capacity and surface charge density of the core-shell microgels.These diverse properties first influenced the swelling behavior,further affecting the interfacial behavior of the microgels,including the oil-water dynamic interfacial tension and air-water compression isotherms.Furthermore,the rheological behavior of the microgel suspensions also displayed distinct dependences on the frequency and temperature,illustrating that the cis-trans molecular structure and crosslinked position of the dicarboxylic acids also significantly influenced the interparticle clustering in the bulk solution.Our results suggest that the pH sensitivity of the cis-trans dicarboxylic acid isomer affects the ionization and surface charge distribution of the core or shell layers of individual microgels,which further determines the interparticle interaction and cooperative rearrangement at interfaces and in the bulk. 展开更多
关键词 MICROGEL Core-shell structure Acid isomer Interfacial behavior RHEOLOGY
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Design and Synthesis of Bis-β-ketoimine Binuclear Titanium Complex Isomers to Probe Bimetallic Synergistic Effect for Ethylene Polymerization
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作者 Ming Zhou Meng-Yuan Xue +3 位作者 Ping-Zhou Huang Ting-Cheng Li Qing-Liang You Guang-Yong Xie 《Chinese Journal of Polymer Science》 2025年第5期756-768,共13页
Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In t... Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect. 展开更多
关键词 Binuclear titanium complex isomer Ethylene polymerization COPOLYMERIZATION Synergistic effect
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Tuning Isomerism Effect in Organic Bulk Additives Enables Efficient and Stable Perovskite Solar Cells
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作者 Qi Zhang Qiangqiang Zhao +9 位作者 Han Wang Yiguo Yao Lei Li Yulin Wei Ruida Xu Chenyang Zhang Erik O.Shalenov Yongguang Tu Kai Wang Mingjia Xiao 《Nano-Micro Letters》 2025年第5期193-205,共13页
Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonra... Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells.The functional groups can passivate undercoordinated ions to reduce nonradiative recombination losses.However,how these groups synergistically affect the enhancement beyond passivation is still unclear.Specifically,isomeric molecules with different substitution patterns or molecular shapes remain elusive in designing new organic additives.Here,we report two isomeric carbazolyl bisphosphonate additives,2,7-Cz BP and 3,6-Cz BP.The isomerism effect on passivation and charge transport process was studied.The two molecules have similar passivation effects through multiple interactions,e.g.,P=O···Pb,P=O···H–N and N–H···I.2,7-CzBP can further bridge the perovskite crystallites to facilitates charge transport.Power conversion efficiencies(PCEs)of 25.88%and 21.04%were achieved for 0.09 cm^(2)devices and 14 cm^(2)modules after 2,7-Cz BP treatment,respectively.The devices exhibited enhanced operational stability maintaining 95%of initial PCE after 1000 h of continuous maximum power point tracking.This study of isomerism effect hints at the importance of tuning substitution positions and molecular shapes for organic additives,which paves the way for innovation of next-generation multifunctional aromatic additives. 展开更多
关键词 Organic additives Molecular simulation Perovskite solar cells PASSIVATION isomeric effect
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High-Dimensional Multi-Objective Computation Offloading for MEC in Serial Isomerism Tasks via Flexible Optimization Framework
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作者 Zheng Yao Puqing Chang 《Computers, Materials & Continua》 2026年第1期1160-1177,共18页
As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays... As Internet of Things(IoT)applications expand,Mobile Edge Computing(MEC)has emerged as a promising architecture to overcome the real-time processing limitations of mobile devices.Edge-side computation offloading plays a pivotal role in MEC performance but remains challenging due to complex task topologies,conflicting objectives,and limited resources.This paper addresses high-dimensional multi-objective offloading for serial heterogeneous tasks in MEC.We jointly consider task heterogeneity,high-dimensional objectives,and flexible resource scheduling,modeling the problem as a Many-objective optimization.To solve it,we propose a flexible framework integrating an improved cooperative co-evolutionary algorithm based on decomposition(MOCC/D)and a flexible scheduling strategy.Experimental results on benchmark functions and simulation scenarios show that the proposed method outperforms existing approaches in both convergence and solution quality. 展开更多
关键词 Edge computing offload serial isomerism applications many-objective optimization flexible resource scheduling
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Evaluating thresholds of Mac-2 binding protein glycosylation isomer in association with clinical outcomes in patients with cirrhosis
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作者 Trung Hieu Doan Khue Minh Nguyen +2 位作者 Xung Van Nguyen Anh Thi Ngoc Pham Nhan Duc Le 《World Journal of Hepatology》 2025年第9期210-219,共10页
BACKGROUND Cirrhosis is a progressive condition characterized by fibrosis that can lead to severe complications and increased mortality.The mac-2 binding protein glyco-sylation isomer(M2BPGi)is a prominent biomarker f... BACKGROUND Cirrhosis is a progressive condition characterized by fibrosis that can lead to severe complications and increased mortality.The mac-2 binding protein glyco-sylation isomer(M2BPGi)is a prominent biomarker for predicting hepatocellular carcinoma(HCC)and cirrhosis-induced esophageal varices(EV).AIM To investigate thresholds of M2BPGi associated with HCC,EV,and decomp-ensation in patients with cirrhosis.METHODS This was a prospective study.A total of 153 patients with cirrhosis who met the inclusion criteria were enrolled.The patients were diagnosed with HCC and EV according to the Baveno VII and European Association for the Study of the Liver guidelines.Baseline serum M2BPGi levels were assessed along with other routine tests.The data analysis aimed to determine the cutoff values of M2BPGi for pre-dicting EV and HCC.RESULTS In the study 85.6%of patients were Child-Pugh B and C.M2BPGi mean cutoff index was 7.1±3.7,showing no significant etiological differences.However,M2BPGi levels varied significantly among Child-Pugh classes,EV classifications,and between patients with and without HCC(P<0.01).M2BPGi cutoff values for predicting HCC,EV,and decompensated cirrhosis were 6.50,6.64,and 5.25,respectively.Mul-tivariate analysis confirmed M2BPGi as an independent risk factor for EV[adjusted odds ratio(aOR):1.3,95%CI:1.08-1.64]and liver decompensation(aOR:2.11,95%CI:1.37-3.83).Area under the curve of M2BPGi for HCC differ-entiation was 0.71.An algorithm combining alpha-fetoprotein(AFP)and M2BPGi detected 26 of 28 HCC cases with 98.04%accuracy vs 10 cases by AFP alone.CONCLUSION Serum M2BPGi predicted cirrhosis complications,including decompensation and varices,especially in HCC.Combined with AFP,it enhanced HCC detection.Future liver biopsy studies are needed for tissue confirmation. 展开更多
关键词 CIRRHOSIS Hepatocellular carcinoma Esophageal varices High-risk esophageal varices Liver decompensation Mac-2 binding protein glycosylation isomer
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