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Photofragment translational spectroscopy at 304 nm from C-H symmetric stretch excited CH_3I [v_1 = 1]

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Science China Chemistry 2014年第6期57卷 902-910页

作者： ZHOU ZhiMin HU LiLi DONG ChangWu ZHANG LiJuan LIU Sheng DU YiKui CHENG Min ZHU QiHe National laboratory of molecular Sciences state key laboratory of molecular reaction dynamics Institute of Chemistry Chinese Academy of Sciences

The 304 nm photodissociation of the C-H symmetric stretch excited CH3I[v1=1,v2=0](v1 denotes the C-H symmetric stretch mode,and v2 denotes the umbrella mode)is studied with our simple photofragment translational *** IR laser is used to excite the ground state CH3I[0,0]to the C-H symmetric stretch excited CH3I[1,0].With IR laser OFF and ON,the fractions of photofragments CH3(ν1,ν2)from the 304 nm photodissociation of CH3I[1,0]have been determined through the photofragment translational spectra(PTS)from measuring I and I*and also through the PTS from measuring CH3(0,0)(1,0)(0,1)and(1,1).The experimental results show that the C-H symmetric stretch vibration(v1=1)in parent molecules is about 66%retained in the photofragments in the I channel,but only 24%in the I**** populations of photofragments CH3(0,2)and(0,3)are higher than CH3(0,0)and(0,1),showing strong inverted population both in I and I*channels.

关键词： photodissociation methyl iodide excited vibrational state photofragment translational spectrum(PTS)

Controls for the generation of high-order harmonics and attosecond pulses by an infrared laser field combined with a low-frequency pulse

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Chinese Physics B 2012年第8期21卷 18-22页

作者：贺海翔郭雅慧何国钟 state key laboratory of molecular reaction dynamics Dalian Institute of Chemical PhysicsChinese Academy of Sciences

We investigate high-order harmonic generations by controlling various quantum paths of harmonics in an infrared laser field which combines a low-frequency pulse. Both classical theory and the quantum wavelet transform method are used to understand the physics of harmonics. By adjusting the carrier envelope phase of the fundamental field, the intensities of harmonic spectra increase and the harmonics in the plateau become regular. Attosecond pulses each with a duration of 58 as are obtained directly by compressing the harmonics, and with phase compensation an isolated attosecond pulse less than 30 as can be generated.

关键词： high-order harmonics isolated attosecond pulse LZH-DICP code

Rapid internal conversion in a symmetric molecule LD 700 studied by means of femtosecond fluorescence depletion

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Chinese Physics B 2009年第1期18卷 142-148页

作者：郭逊敏宛岩夏安东王素凡刘建勇韩克利 state key laboratory of molecular reaction dynamics and Beijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of Sciences College of Chemistry and Materials Science Anhui Normal University state key laboratory of molecular reaction dynamics Dalian Institute of Chemical PhysicsChinese Academy of Sciences

The rapid internal conversion dynamics at room temperature is determined by using the femtosecond time-resolved fluorescence depletion measurements of a complex solvated molecule of LD 700 （rhodamine 700） combined with steadystate absorption and fluorescence spectroscopy, as well as quantum chemical calculation. The molecule is excited by a 50 fs laser pulse at 400 nm which directly populated the highly excited singlet state, the rapid internal conversions （ICs） are observed, which leads to the directional changes of the emission transition moment following photoexcitation to the highly excited singlet state S5 of LD 700.

关键词： femtosecond fluorescence depletion internal conversion (IC) solvation

Boosting Oxygen Evolution reaction Performance on NiFe‑Based Catalysts Through d‑Orbital Hybridization

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Nano-Micro Letters 2025年第1期17卷 281-292页

作者： Xing Wang Wei Pi Sheng Hu Haifeng Bao Na Yao Wei Luo state key laboratory of New Textile Materials and Advanced Processing Technology Key Laboratory of New Textile Materials and Applications of Hubei ProvinceSchool of Materials Science and EngineeringWuhan Textile UniversityWuhan 430200People’s Republic of China College of Chemistry and molecular Sciences Wuhan UniversityWuhan 430072People’s Republic of China

Anion-exchange membrane water electrolyzers(AEMWEs)for green hydrogen production have received intensive attention due to their feasibility of using earth-abundant NiFe-based *** introducing a third metal into NiFe-based catalysts to construct asymmetrical M-NiFe units,the d-orbital and electronic structures can be adjusted,which is an important strategy to achieve sufficient oxygen evolution reaction(OER)performance in ***,the ternary NiFeM(M:La,Mo)catalysts featured with distinct M-NiFe units and varying d-orbitals are reported in this *** and theoretical calculation results reveal that the doping of La leads to optimized hybridization between d orbital in NiFeM and 2p in oxygen,resulting in enhanced adsorption strength of oxygen intermediates,and reduced rate-determining step energy barrier,which is responsible for the enhanced OER *** critically,the obtained NiFeLa catalyst only requires 1.58 V to reach 1 A cm^(−2) in an anion exchange membrane electrolyzer and demonstrates excellent long-term stability of up to 600 h.

关键词： NiFe-based catalysts d-orbital coupling Oxygen evolution reaction Anion exchange membrane electrolyzer

Rational design of a visible-light photochromic diarylethene:a simple strategy by extending conjugation with electron donating groups

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Science China Chemistry 2019年第4期62卷 451-459页

作者： Shanliang Tang Fengling Song Meiheng Lu Keli Han Xiaojun Peng state key laboratory of Fine Chemicals Dalian University of Technology state key laboratory of molecular reaction dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences

Photochromic diarylethenes have been widely used in many fields. However, their cyclization process must be induced by UV light. In this article, a simple strategy is developed by extending π-conjugation with electron donating groups. The modified dirylethene derivative can photocyclolize under 405-nm light with a good photochromic efficiency. Meanwhile, its absorption and moderate fluorescence can be switched effectively in both directions by visible lights(405 and 520 nm, respectively) in different solutions and in living cells. We believe that this simple method will become a versatile strategy for developing various dirylethylenes with visible-light photochromism.

关键词： diarylethylenes visible-light photochromism photoreaction quantum yield fluorescence photoswitching

Mass spectrometric study of Ag's clustering ability with O,S and Se

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Chinese Science Bulletin 2001年第7期46卷 543-549页

作者： Xiaopeng Xing Xia Zhang Xiang Zhao Zhen Gao state key laboratory of molecular reaction dynamics Center of Molecular Science Institute of Chemistry Beijing China

Samples Ag/O/S, Ag/O/Se and Ag/S/Se were ablated directly by laser to produce clusters. The detection was performed with a time-of-flight mass spectrometer (TOF MS). The cluster ions produced had the following distribution: Ag/S binary cluster ions for sample Ag/O/S, Ag/Se binary cluster ions for sample Ag/O/Se, and Ag/Se binary cluster ions and Ag/S/Se ternary cluster ions as the main products for sample Ag/S/Se. Laser double ablation reactor was used to study the reaction between Ag/S(Se, O) binary clusters and Se(S) homoclusters. The experiments show that Se clusters can replace S and O in Ag/S and Ag/O clusters while S clusters can replace O in Ag/O clusters. This fact indicates the sequence of the clustering ability of Ag presented as follows: Ag/Se > Ag/S > Ag/O, which was also proved by theoretical calculation. The reason of this tendency was considered to be the different abilities of the elements’ polarization, which acts on the stability of clusters.

关键词： laser ablation time-of-flight mass spectrometer Ag/O(S Se) atom clusters clustering ability.

Time-Resolved FTIR Study on the reaction of CHCl2 with NO2

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Chinese Journal of Chemical Physics 2009年第2期22卷 134-138页

作者： Kun-hui Liu Chun-fan Yang Huan Wang Wei-qiang Wu Hong-mei Su state key laboratory of molecular reaction dynamics Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

The environmentally important free radical reaction of chlorinated methyl CHCl2 with NO2 was investigated by step-scan time-resolved FTIR （TR-FTIR） emission spectroscopy. Vibrationally excited products of CHClO, NO, CO, and HCl are observed in the high-resolution IR emission spectra and three possible reaction channels are therefore elucidated. In particular, the product CO is newly detected and the product HCl is identified explicitly as a yield from the CHCl2＋NO2 reaction, taking advantage of the sensitive detection of HCl and CO with TR-FTIR. These results are of particular interests to understand the related realistic chemical processes including atmospheric photochemistry, biofuel combustion, waste destruction, and smoking fire.

关键词： TR-FTIR Dichloromethyl NO2 reaction product channel

Theoretical Study of 1,3-Dipolar Cycloaddition of Hydrazoic Acid to Substituted Ynamines

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Chinese Journal of Chemical Physics 2009年第2期22卷 143-148页

作者： Xiao-fang Chen Kun Yang Ke-li Han state key laboratory of molecular reaction dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

The 1,3-dipolar cycloaddition reactions of various substituted ynamines with hydrazoic acid were theoretically investigated with the high-accuracy CBS-QB3 method. Two regioisomers, 4-amine, and 5-amine substituted adducts, were obtained, with the former as the preferred yield. This regioselectivity is rationalized by the frontier molecular orbital theory. The reactivity and synchronicity are enhanced with the increase of the electron-withdrawing character of the substitute on ynamine fragment. The calculations also show that the effect of solvent increases the activation energy, and the reaction becomes even harder in polar solvent.

关键词： 1,3-dipolar cycloaddition Hydrazoic acid Internal alkyne CBS-QB3 Solvent effect Substituent effect Frontier molecular orbital theory

Direct Observation of Ethanol Photocatalysis on Rutile TiO2(110) Surface

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Chinese Journal of Chemical Physics 2015年第4期28卷 -页

作者： Dong Wei Xian-chi Jin Dong-xu Dai Zhi-bo Ma Xue-ming Yang state key laboratory of molecular reaction dynamics Dalian Institute of Chemical Physics Chinese Academy of Science Dalian 116023 China

Photocatalytic dissociation of ethanol molecules on the rutile TiO2(110) surface after UVirradiation has been investigated by scanning tunneling microscope at 80 K. Most of the ethanol molecules adsorb molecularly at Ti sites, similar to the case of methanol. After UVirradiation, two different protrusions of products were observed, one of them has been identified by the technique of tip manipulation, which was likely composed of an acetaldehyde in the middle and two bridge-bonded hydroxyls on both neighbored oxygen sites. Multi-time irradiation experiments have also been performed to further understand the relationship between the two protrusions and the process of ethanol photocatalytic dissociation. These results provide detailed insights into the photocatalysis of ethanol on rutile TiO2(110), which would help us to understand how phtotocatalytic reactions of ethnaol proceed at the fundamental level.

关键词： Titanium dioxide Scanning tunneling microscope Photocatalysis