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substituent effect on the molecular stability,group interaction,detonation performance,and thermolysis mechanism of nitroamino-substituted cyclopentanes and cyclohexanes

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Science China Chemistry 2008年第12期51卷 1231-1245页

作者： QIU Ling GONG XueDong JU XueHai XIAO HeMing Institute for Computation in Molecular and Material Science School of Chemical EngineeringNanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Nuclear Medicine Ministry of HealthJiangsu Institute of Nuclear MedicineWuxi 214063China

Density functional theory (DFT) method has been employed to study the effect of nitroamino group as a substituent in cyclopentane and cyclohexane, which usually construct the polycyclic or caged nitra-mines. Molecular structures were investigated at the B3LYP/6-31G** level, and isodesmic reactions were designed for calculating the group interactions. The results show that the group interactions ac-cord with the group additivity, increasing with the increasing number of nitroamino groups. The dis-tance between substituents influences the interactions. Detonation performances were evaluated by the Kamlet-Jacobs equations based on the predicted densities and heats of formation, while thermal stability and pyrolysis mechanism were studied by the computations of bond dissociation energy (BDE). It is found that the contributions of nitroamino groups to the detonation heat, detonation velocity, detonation pressure, and stability all deviate from the group additivity. Only 3a, 3b, and 9a-9c may be novel potential candidates of high energy density materials (HEDMs) according to the quantitative cri-teria of HEDM (ρ≈ 1.9 g/cm3, D ≈ 9.0 km/s, P ≈ 40.0 GPa). Stability decreases with the increasing number of N-NO2 groups, and homolysis of N-NO2 bond is the initial step in the thermolysis of the title com-pounds. Coupled with the demand of thermal stability (BDE > 20 kcal/mol), only 1,2,4-trinitrotriazacy-clohexane and 1,2,4,5-tetranitrotetraazacyclohexane are suggested as feasible energetic materials. These results may provide basic information for the molecular design of HEDMs.

关键词： density functional theory (DFT) substituent effect monocyclic nitramine high energy density material (HEDM) group interaction detonation performance thermal stability bond dissociation energy (BDE)

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Remote substituent effects on catalytic activity of metal-organic frameworks: a linker orbital energy model

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npj Computational Materials 2023年第1期9卷 1747-1755页

作者： Zhenzhen Wang Huan Meng Xuejiao J.Gao Jia-Jia Zheng Xingfa Gao Laboratory of Theoretical and Computational Nanoscience National Center for Nanoscience and Technology of ChinaBeijingChina CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and Technology of ChinaBeijingChina College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchangChina

The Hammett equation is commonly used to theoretically depict the remote electronic effects of substituents on catalytic activitiesof metal nodes of metal-organic frameworks (MOFs). However, the application of the theory to MOF catalysts usually encountersproblems because it relies heavily on empirical parameters with unknown transferability. To develop an alternative predictiontheory, the linker orbital energy model has been proposed by density functional theory calculations. The model provides a simplemethod to approximately depict the remote electronic substituent effects on catalytic activities of metal nodes of MOFs, and itsgeneral applicability to MOFs is supported by extensively revisiting the structure-activity relationships reported in the *** model can be used to design catalytic activity of metal nodes of MOFs by engineering the electronic properties of linkers andsubstituents.

关键词： substituent catalytic orbital

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Effects of N-1 substituent on the phototoxicity of fluoroquinolone antibiotics: comparison of pefloxacin and difloxacin

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Nuclear Science and Techniques 2020年第7期31卷 34-45页

作者： Jian-Feng Zhao Yan-Cheng Liu Yu-Lie Xu Wen-Feng Wang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Science Beijing 100049China

The photophysics and photochemistry of pefloxacin(PEF),a 1-ethyl-substituted fluoroquinolone(FQ)antibiotic,were studied using transient,steady-state experimental methods and computational *** fundamental photoproperties of PEF and its phototoxicity toward lysozyme,a single-chain protein,were compared with those of a 1-fluorophenyl-substituted FQ antibiotic,difloxacin(DIF).The results showed that the phototoxicity was significantly decreased by the insertion of the bulky1-fluorophenyl substituent(the phototoxicity of DIF was approximately one-quarter of that observed for PEF).This trend was attributed to the lowest lying singlet state with sizeable oscillator strength(f C 0.1)being shifted from319 nm in PEF to 266 nm in DIF upon the insertion of the bulky substituent at the 1-position,as investigated by using computational *** addition,95%of the solar UV irradiation that reaches the earth’s surface has wavelength[315 ***,reducing the most effective excitation wavelength by optimizing the substituent at the1-position may be a promising strategy to alleviate the phototoxicity of FQ *** findings may be applied to other FQ antibiotics because a large number of phototoxicity studies on FQ antibiotics with different substituents at the 1-position can prove these finding’s ***,an FQ antibiotic bearing a chlorine and bulky substituent at the 8-and 1-positions,respectively,exhibits no phototoxicity is the most recent example reported to *** the best of our knowledge,this is the first transient and steady-state study of the effect of the N-1 substituent on the photochemistry and phototoxicity of FQ *** findings will be beneficial to the development of novel FQ antibiotics without phototoxicity.

关键词： substituent transient photochemistry

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Electron structure and substituent effects in o-,m-,p-IC_6H_4OCH_3 iodoanisoles

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Science China Chemistry 2009年第11期52卷 1932-1937页

作者： TONG ShengRui,WANG WeiGang,MA ChunPing,GE MaoFa & WANG DianXun Beijing National Laboratory for Molecular Sciences(BNLMS),State Key Laboratory for Structural Chemistry of Unstable and Stable Species,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China Beijing National Laboratory for Molecular Sciences (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China

The electronic structures and substituent effects in o-,m-,and p-iodoanisoles have been investigated by ultraviolet photoelectron spectroscopy(UPS).The observed UPS bands were analyzed by combining empirical arguments and theoretical *** to the electron-donating nature of both iodoand methoxy substituents,the first ionization potentials of the three iodoanisoles are lower than those of iodobenzene and *** presence of the two substituents in iodoanisoles leads to an electronrich structure,which might contribute to the observed high reactivity of iodoanisoles in a number of organic reactions.

关键词： electronic structures substituent effects ultraviolet photoelectron spectroscopy reactivity

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Theoretical Studies on the Aminolysis of Ester: Effects of the Catalysis and substituent to the Reaction of Methyl Indole-3-acetate with Ammonia

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Chinese Journal of Structural Chemistry 2019年第6期38卷 855-866页

作者： ZHANG Liang CHEN Rong LIANG Guo-Ming College of Chemistry Chongqing Normal University

A comprehensive exploration of the aminolysis mechanism for methyl indole-3-acetate with ammonia is carried out by employing the B3 LYP/6-311++G(d,p), M06-2 X/6-311++G(d,p) and MP2/6-311++G(d,p)//M06-2 X/6-311++G(d,p) levels. Two alterative reaction channels of the concerted and addition/elimination stepwise processes including the uncatalyzed, base-catalyzed reactions are taken into consideration. Subsequently, the substituent effects and solvent effects in methanol are also evaluated at the M06-2 X/6-311++G(d,p) level. The calculated results indicate that the calculated values of M06-2 X level are quite close to those of MP2, the stepwise pathway has more advantages to the concerted one for all of the reaction processes and the catalyst facilitates the proton migration and decreases the energy barriers as well. It is shown that the most preferred mechanism is the based-catalyzed stepwise process, the substituent of NH2 group slightly accelerates all the aminolysis reaction processes, and the solvent effect does not remarkably change the mechanism of the reaction.

关键词： aminolysis methyl indole-3-acetate mechanism catalytic effect substituent effect

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Theoretical studies on the spectroscopic properties and the substituent effects of pyridyl triazole Os(Ⅱ) complexes

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Science China Chemistry 2009年第3期52卷 261-265页

作者： WU YuHui, ZHOU Xin & ZHANG HongXing State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China State Key Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University Changchun China

To explore the spectroscopic properties of pyridyl triazole Os(Ⅱ) complexes and how the substituent effects affect the spectroscopic properties of [Os(ptz)2L2] (L=PH3; ptzH=(2-pyridyl)-1,2,4-triazole) (1), [Os(bptz)2L2] (bptzH=3-tert-butyl-5-(2-pyridyl)-1,2,4-triazole) (2), [Os(fptz)2L2] (fptzH=3- (trifluoreomethyl)- 5-(2-pyridyl)-1,2,4-triazole) (3), and [Os(fbtz)2L2] (fbtzH=3-(trifluoreomethyl)-5-(4-tert-butyl- 2-pyridyl)-1,2, 4-triazole) (4), the density functional theory (DFT) method at the B3LYP level was used to optimize the geometrical structures in the ground and excited state. The absorption and emission properties of the dichloromethane solution were predicted at the time-dependent density functional theory (TD-DFT, B3LYP) level associated with the PCM solvent effect model, the transitions characters of them were assigned. Important correlations between substituent effects and emission spectra and the quantum yield have been obtained by comparing and analyzing the calculated results.

关键词： pyridyl triazole Os(Ⅱ) complexes excited state density functional theory TD-DFT substituent effects

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Theoretical Insights into the substituent Effects on the Fluorescence of Boron Complexes of 2-(Benzothiazol-2-yl)phenols: a Quantum Mechanics Study

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Chinese Journal of Structural Chemistry 2020年第2期39卷 243-254,184页

作者： LI Hui-Xue WANG Xiao-Feng ZHU Yuan-Cheng YUAN Kun LV Ling-Ling LI Zhi-Feng School of Chemical Engineering and Technology Tianshui Normal UniversityTianshui 741001China

The performance of organic fluorescent materials can be improved by chemical substitutions with auxochrome groups such as amino to increase solubility, alter emitting color, or modify film quality. The complex 6,6-difluoro-6-bora-5-oxa-11-thia-6 a-aza-benzo[a]fluorine(BOBTP) and its derivatives, which possess excellent luminescent property at room temperature, were theoretically simulated by density functional theory. The geometries of the ground state and the first excited state of BOBTPs complexes were investigated and their bond parameters were obtained. Further, these bond parameters are compared with each other, and the computational wavelengths of maximum absorption and emission of studied complexes match up with the experimental values. It was found that amino substituent bonding to appropriate positions of BOBTP can reduce the reorganization energy significantly, which is ascribed to electron-donating effect of the amino group. The reorganization energy also plays an important role in the fluorescence quantum yield of all the BOBTPs. In particular, the radiative decay of complexes 3 and 4 is dominant due to the smaller reorganization energies, so their fluorescence quantum yield is almost 1, on the contrary the non-radiative decay and intersystem crossing rate of both the 1 and 2 can not be ignored for the larger reorganization energies, and the corresponding fluorescence quantum yields were calculated when the radiative decay rate(kr) and nonradiative decay rate(k(nr)) were taken into account.

关键词： theoretical study fluorescence spectrum BOBTPs substituent effects

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Structure-property relationships of fluoroolefins *** effects on the kinetic parameters of the thermal dimerization of trifluorostyrenes

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化学学报(英文版) 1985年第4期3卷 369-375页

作者： JIANG Xi-Kui JI Guo-Zhen YU Chong-Xi Shanghai Institute of Organic Chemistry,Academia Sinica,345 Lingling Lu,Shanghai,China Shanghai Institute of Organic Chemistry Academia Sinica 345 Lingling Lu Shanghai China

The rate constants（k2）of the thermal dimerization of seven substituted trifluorostyrenesin n-hexane solution have been determined in the temperature range 110°—160℃.In general,nogood correlation can be obtained with various Hammett type substituent parameters,e.g.,σ,σ+,σ-,σ0,σR,σR+,σR-,and σR0 *** results accord with the view that in addition to the polar effects,theabilities of the substituent to delocalize the spin also play important roles in affecting the rates *** for previously reported successful correlations of polar substituentconstants with radical reactions are presented.

关键词： substituent hexane substituted constants polar affecting stabilize rings thermally bonds

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Controlled Radical Polymerization of Styrene Mediated by Xanthene-9-thione and Its Derivatives

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Chinese Journal of Polymer Science 2018年第12期36卷 1303-1311页

作者： Hao-Yu Yu Jiao Wang Jian-Wei Shao Dong Chen Shi-Chao Wang Li Wang Wan-Tai Yang College of Materials Science and Engineering Beijing University of Chemical Technology State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing Advanced Innovation Centre for Soft Matter Science and Engineering Beijing University of Chemical Technology

In our present work, a novel controlled radical polymerization system is developed based on xanthene-9-thione （XT）. It was found that the radical polymerization of styrene （St） became controlled in the presence of a small amount of XT. At the early stage of the polymerization, the polymerization rate was relatively low and the as-formed polystyrene （PS） had low number-average molecular weight （Mn） and narrow polydispersity （D）. After XT was consumed, the polymerization rate increased dramatically and the Mn of PS increased gradually with polymerization proceeding. When the polymerization of St was carried out with a proper molar ratio of initiator to XT and at an appropriate temperature, shortened slow polymerization stage and good control over Mn could be achieved. To further improve the regulating ability of XT, a series of substituent groups （-CF3, --CH（CH3）2, --N（CH3）2） were introduced onto the xanthene ring of XT, and the effects of these derivatives on the polymerization of St were investigated in detail. UV-Vis spectroscopy was carried out to monitor the concentration of XT during the polymerization and the chemical structure of the as-formed PS was fully characterized by IH- NMR and ESI-MS analysis. A possible mechanism involving the formation and evolution of the cross-termination products was proposed to interpret the observed polymerization behavior.

关键词： Controlled radical polymerizaton Xanthene-9-thione Styrene substituent ESI-MS

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Treatment of naphthalene derivatives with iron-carbon micro-electrolysis

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Transactions of Nonferrous Metals Society of China 2006年第6期7卷 1442-1447页

作者：王玉萍王连军彭盘英陆天虹 School of Chemical Engineering Nanjing University of Science and Technology 2.School of Chemistry and Environmental Science Nanjing Normal UniversityNanjing 210097China School of Chemistry and Environmental Science Nanjing Normal University

The degradation of five naphthalene derivatives in the simulated wastewater was investigated using the iron-carbon micro-electrolysis *** optimal initial pH of solution and adsorption of iron-carbon and removal efficiency of the total organic carbon(TOC)were *** results show that the removal efficiency of the naphthalene derivatives can reach 48.9%?92.6% and the removal efficiency of TOC is 42.8%?78.0% for the simulated wastewater with 200 mg/L naphthalene derivatives at optimal pH of 2.0?2.5 after 120 min *** degradation of five naphthalene derivatives with the micro-electrolysis shows the apparent first-order kinetics and the order of removal efficiency of the naphthalene derivatives is sodium 2-naphthalenesulfonate,2-naphthol,2,7-dihydroxynaphthalene,1-naphthamine,1-naphthol-8-sulfonic acid in *** is illustrated that the substituents of the naphthalene ring can affect the removal efficiency of naphthalene due to their electron-withdrawing or electron-donating ability.

关键词： cast iron scrap micro-electrolysis naphthalene substituent wastewater treatment

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