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Kinetic and mechanism of the reaction between Cl and several mono-methyl branched alkanes

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Journal of Environmental Sciences 2024年第1期135卷 474-482页

作者： Yan Chen Weigang Wang Junling li li Zhou Bo Shi Cici Fan Ke Wang Hao Zhang Hong li maofa ge state key laboratory for structural chemistry of unstable and stable species Beijing National Laboratory for Molecular Sciences(BNLMS)CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China state key laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China National Engineering Research Center for Flue Gas Desulfurization Department of Environmental Science and EngineeringSichuan UniversityChengdu 610065China College of chemistry and Materials Science Hebei Normal UniversityShijiazhuang 050024China

Branched alkanes are ubiquitous in the troposphere and play an important role in the chemical *** this work,the rate constants and products for the reaction of Cl atoms with 3-methylhexane and 2-methylheptane were measured at room temperature(298±0.2K)and atmospheric pressure using a conventional relative rate *** rate constants of 3-methylhexane and 2-methylheptane in units of cm~3/(mol·sec)are(3.09±0.31)×10^(-10)and(3.67±0.40)×10^(-10),***,the corresponding atmospheric lifetime of the studied branched alkanes with Cl was 6.92-89.90 hours and 5.82-75.69 hours,*** estimated atmospheric lifetimes indicated that the reaction with Cl atoms could be the most important atmospheric degradation pathway for 3-methylhexane *** gas-phase products of the reactions were identified and quantified,and particle-phase products were also *** atmosphere oxidation mechanism of Cl atoms with 3-methylhexane and 2-methylheptane is *** SOA yields of 3-methylhexane and 2-methylheptane from the reaction of Cl atoms were determined to be7.96%±0.89%and 13.35%±1.50%***,the results reveal that the primary loss process of branched alkanes is the reaction with Cl atoms,which impacts its degradation on a regional scale.

关键词： 3-Methylhexane 2-Methylheptane Chlorine atoms Kinetics Mechanism

HeI photoelectron spectroscopic (PES) studies of the electronic structure in ω-heterocycle a-cyano polyenic ethyl ester compounds

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Chinese Journal of chemistry 1996年第3期14卷 211-216页

作者： li, Ying li, Sheng CHEN, Ben-Ming WANG, Dian-Xunstate key laboratory for structural chemistry of unstable and stable species, Institute of chemistry, Chinese Academy of Sciences, Beijing 100080, China state key laboratory for structural chemistry of unstable and stable species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

HeI photoelectron spectra of w-heterocycle a-cyano polyenic ethyl ester compounds (1-6) have been given in this paper. Assignment of the spectra is also done with the aid of HeI photoelectron spectroscopic (PES) results of smaller molecules which have similar atomic group to the molecules studied, and the aid of MNDO molecules orbital calculations. The lowest PES experimental ionization potentials (IPs in eV) of different molecules reduce gradually with the increasing number of ethylenic group. The -CO2C2H5 group can be only considered as a substituent.

关键词： HeI photoelectron spectroscopy (PES) w-heterocycle a-cyano polyenic ethyl ester compounds homologous linearity rule

Study on the atmospheric photochemical reaction of CF_3 radicals using ultraviolet photoelectron and photoionization mass spectrometer

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Science China chemistry 2008年第4期51卷 316-321页

作者： YAO li1,2, DU lin1,2, YIN Shi1,2 & ge maofa1 1 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 100080, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100080, 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 Graduate University of Chinese Academy of Sciences Beijing China

A study of the atmospheric photochemical reaction of CF3 radical with CO and O2 was performed by using a homemade ultraviolet photoelectron spectrometer-photoionization mass spectrometer (PES- PIMS). The electronic structures and mechanism of ionization and dissociation of CF3OC(O)OOC(O)- OCF3 were investigated. It was indicated that the two bands on the photoelectron spectrum of CF3OC(O)OOC(O)OCF3 are the result of ionization of an electron from a lone pair of oxygen and a fluo- rine lone pair of CF3 group. The outermost electrons reside in the oxygen lone pair. The experimental and theoretical first vertical ionization energy is 13.21 and 13.178 eV, respectively, with the PES and OVGF method. They are in good agreement. The photo ionization and dissociation processes were discussed with the help of theoretical calculations and PES-PIMS experiment. After ionization, the parent ions prefer the dissociation of the C-O bond and giving the fragments CF3OCO+ and CF3+. It demonstrated that the ultraviolet photoelectron and photoionization mass spectrometer could be ap- plied widely in the study of atmospheric photochemical reaction.

关键词： photochemical reaction CF3 radical ultraviolet photoelectron and photoionization mass spectroscopy transient species

Electronic Structure Study of three 2,5-disubstituted thiophenes

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Electronic Structure Study of three 2,5-disubstituted thioph...

A flame-retardant binder with high polysulfide affinity for safe and stable lithium–sulfur batteries

中国化学会第五届全国结构化学学术会议

作者： Chunping Ma li Yao maofa ge Dianxun Wang Beijing National laboratory for Molecular Science (BNLMS),state key laboratory for structural chemistry of unstable and stable species,Institute of chemistry,Chinese Academy of Sciences,Beijing,100080,China

The electronic structures of three 2,5-disubstituted thiophenes (2-bromo-5-chlorothiophene,2-bromo-5-methylthiophene and 2-bromo-5-nitrothiophene)have been studied by ultraviolet photoelectron spectroscopy(UPS).Combined the empirical arguments and theoretical method,the observed bands were *** analysis of electronic effects of the donor/acceptor substituted groups is essential for the reliable assignment of the observed photoelectron *** highest occupied molecular orbital(HOMO)for each compounds is mainly the ionization of π *** analysis of the natural bond orbital(NBO)second-order interaction energies has also been employed to understand the nature of the intermolecular interactions between the substitutents and the parent *** investigation of π and n orbitals ionization potentials enabled us to describe the correlation between substituent effects and relative reaetivities of the substituted thiophenes.

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来源： cnki会议评论

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Science China chemistry 2024年第3期67卷 1028-1036页

作者： Guowei Yu Guofeng Ye Cheng Wang Chenyang Wang Zhaoyun Wang pu Hu Yu li Xi-Xi Feng Shuang-Jie Tan Min Yan Sen Xin Zhitian liu Hubei key laboratory of Plasma chemistry and Advanced Materials Hubei Engineering Technology Research Center of Optoelectronic and New Energy MaterialsSchool of Materials Science and EngineeringWuhan Institute of TechnologyWuhan 430205China state key laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China CAS key laboratory of Molecular Nanostructure and Nanotechnology CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China

lithium-sulfur(li-S) batteries have shown promises for the next-generation, high-energy electrochemical storage, yet are hindered by rapid performance decay due to the polysulfide shuttle in the cathode and safety concerns about potential thermal runaway. To address the above challenges, herein, we show a flame-retardant cathode binder that simultaneously improves the electrochemical stability and safety of batteries. The combination of soft and hard segments in the polymer framework of binders allows high flexibility and mechanical strength for adapting to the drastic volume change during the li(de)intercalation of the S cathode. The binder contains a large number of polar groups, which show the high affinity to polysulfides so that they help to anchor active S species at the cathode. These polar groups also help to regulate and facilitate the li-ion transport, promoting the kinetics of polysulfide conversion reaction. The binder contains abundant phosphine oxide groups, which, in the case of battery's thermal runaway, decompose and release PO· radicals to quench the combustion reactions and stop the fire. Consequently, li-S batteries using the new cathode binder show the improved electrochemical performance, including a low-capacity decay of 0.046% per cycle for 800 cycles at 1 C and favorable rate capabilities of up to 3 C. This work offers new insights on the practical realization of high-energy rechargeable batteries with stable storage electrochemistry and high safety.

关键词： lithium–sulfur battery polymer binder polysulfide affinity flame retardancy

The effects of detergents DDM and β-OG on the singlet excited state lifetime of the chlorophyll a in cytochrome b_6f complex from spinach chloroplasts

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Science China(life Sciences) 2007年第4期50卷 505-510页

作者： CHEN XiaoBo1,3, ZHAO XiaoHui2, ZHANG JianPing2, li liangBi1& KUANG TingYun1 1 key laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 2 state key laboratory for structural chemistry of unstable and stable species, Institute of chemistry, Chinese Academy of Sci- ences, Beijing 100080, China 3 Graduate University of Chinese Academy of Sciences, Beijing 100039, China key laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany Chinese Academy of SciencesBeijing 100093 China Graduate University of Chinese Academy of Sciences Beijing 100039 China state key laboratory for structural chemistry of unstable and stable species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China key laboratory of Photosynthesis and Environmental Molecular Physiology Institute of Botany Chinese Academy of SciencesBeijing 100093 China

The singlet excited state lifetime of the chlorophyll a (Chl a) in cytochrome b6f (Cyt b6f) complex was reported to be shorter than that of free Chl a in methanol, but the value was different for Cyt b6f com-plexes from different sources (~200 and ~600 ps are the two measured results). The present study demonstrated that the singlet excited state lifetime is associated with the detergents n-dodecyl-β-D- maltoside (DDM) and n-octyl-β-D-glucopyranoside (β-OG), but has nothing to do with the different sources of Cyt b6f complexes. Compared with the Cyt b6f dissolved in β-OG, the Cyt b6f in DDM had a lower fluorescence yield, a lower photodegradation rate of Chl a, and a shorter lifetime of Chl a excited state. In short, the singlet excited state lifetime, ~200 ps, of the Chl a in Cyt b6f complex in DDM is closer to the true in vivo.

关键词： cytochrome b6f detergent chlorophyll a singlet excited state lifetime singlet oxygen

From titanates to TiO2 nanostructures:Controllable synthesis,growth mechanism,and applications

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中国科学:化学 2012年第11期42卷 1649-1649页

作者： XU DongSheng 1,2,li JianMing 1,YU YuXiang 1,3 & li JingJian 1 1 Beijing National laboratory for Molecular Sciences,state key laboratory for structural chemistry of unstable and stable species College of chemistry and Molecular Engineering,Peking University,Beijing 100871,China 2 Science and Technology on Electro-Optical Information Security Control laboratory,Sanhe 0652.1,China 3 School of chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510640,China Beijing National laboratory for Molecular Sciences state key laboratory for structural chemistry of unstable and stable species College of chemistry and Molecular Engineering Peking University Beijing 100871 China Science and Technology on Electro-Optical Information Security Control laboratory Sanhe 0652.1 China School of chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 China

The design and fabrication of nanostructures based on titanium dioxide (TiO 2) have attracted much attention because of their low cost,non-toxicity,stability,and potential applications in industry and ***,one-dimensional (1D) structured titanates have been used as titanium source to prepare TiO 2 nanostructures with various crystalline phases,shapes,sizes,exposed facets,and hierarchical *** the synthetic strategies,hydrothermal method is a facile route to controllable preparation of well-crystalline TiO 2 in one ***,we review our recent progress in transferring 1D titanates into TiO 2 nanostructures through hydrothermal method,including the transformation mechanism and applications.

关键词： TiO2 titanate hydrothermal nanostructure quasi-one-dimensional

Fluorescence dynamics of interactions between polyamide PyPyPyβDp and DNA

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Science China chemistry 2006年第1期49卷 75-80页

作者： ZHANG Huijuan1,2, WANG Jin3, WU Yishi1, YUAN Gu3, AI Xicheng1, WANG li4 & ZHANG Jianping1 1. state key laboratory for structural chemistry of unstable and stable species, Institute of chemistry, Chinese Academy of Sciences, Beijing 100080, China 2. School of life Science and Technology, Beijing Institute of Technology, Beijing 100081, China 3. College of chemistry and Molecular Engineering, Peking University, Beijing 100080, China 4. Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China Correspondence should be addressed to Ai Xicheng and Zhang Jianping state key laboratory for structural chemistry of unstable and stable species Institute of Chemistry Chinese Academy of Sciences Beijing China School of life Science and Technology Beijing Institute of Technology Beijing China College of chemistry and Molecular Engineering Peking University Beijing China Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing China

The photophysical properties of the polyamide PyPyPyβDp (PPP) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. It was found that the excited-state properties of PPP are very sensitive to solvents. In TKMC buffer PPP exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity PPP showed the blue-shifted peak position, increased inten-sity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 32 ps for PPP, which verified that PPP bound into the minor groove of DNA duplex.

关键词： polyamide (PPP), calf thymus DNA (ctDNA), time-resolved fluorescence spectroscopy, recognition dynamics.

Enzyme Dynamics of AIKB

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Enzyme Dynamics of AIKB