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Solvent Effect on the Photoinduced Electron Transfer Reaction Between Thioxanthen-9-one and Diphenylamine

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

作者： lin Chen Qiao-hui Zhou Xiang liu Xiao-guo Zhou shi-lin liu Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics University of Science and Technology of ChinaHefei 230026 China

Photoinduced chemical reaction between thioxanthen-9-one (TX) and diphenylamine (DPA) were investigated by the nanosecond laser flash photolysis. With photolysis at 355 nm, the triplet TX (3TX*) is produced via a Franck-Condon excitation and intersystem crossing. In the transient absorption spectra of the reduction of 3TX* by DPA in pure and aqueous CH3CN, four bands are clearly observed and assigned to absorption of 3TX*, TXH·, TX·− and DPA·+, respectively. With the increase of solvent polarity, the blue-shift was observed for all absorption bands of the intermediates. With the aid of dynamic decay curves, an electron transfer followed by a protonation process is confirmed for the reduction of 3TX* by DPA. The quenching rate constants of 3TX* by DPA very slightly decrease from 9.7×109 L/(mol·s) in pure CH3CN, to 8.7×109 L/(mol·s) in CH3CN:H2O (9:1), 8.0×109 L/(mol·s) in CH3CN:H2O (4:1) and 7.5×109 L/(mol·s) in CH3CN:H2O (1:1). Therefore water plays a minor role in the title reaction, and moreover no obvious medium effect of solvent polarity is observed for the electron transfer between 3TX* and DPA, indicating that the 3nπ* and 3ππ* states of TX have the approximate ability to attract an electron from DPA.

关键词： Electron transfer Protonation Reaction mechanism Absorption spectra Laser flash photolysis

Populations of Ethanol Conformers in Liquid CCI4 and CS2 by Raman Spectra in OH Stretching Region

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Chinese Journal of Chemical Physics 2015年第3期28卷 245-252,I0001页

作者： Nai-yin Hu Ke lin Xiao-guo Zhou shi-lin liu Hefei National Laboratory for Physical Sciences at the Microscale Department of Chemical PhysicsUniversity of Science and Technology of China Hefei 230025 China Synergetic Innovation Center of Quantum Information & Quantum Physics University of Science and Technology of China Hefei 230026 China

Combining Raman spectroscopy with density functional theory, the populations of the trans- and gaucheethanol conformers are investigated in carbon tetrachloride （CC14） and carbon disulfide （CS2）. The spectral contributions of two ethanol conformers are identified in OH stretching region. The energy difference between both conformers is estimated with the aid of the calculated Raman cross sections. It can be seen that the trans- ethanol is more stable in CC14 and CS2 solutions. The spectra are also obtained at different temperatures, and it is found the van＇t Hoff analysis is invalid in these solutions. By taking accounts of the Boltzmann distribution and theoretical Raman cross section, the energy difference is found to be increased with temperature, which shows the weak intermolecular interactions can enhance the population of transethanol.

关键词： Raman spectroscopy Ethanol Conformer Energy difference

High-resolution Absorption Spectra of Acetylene in 142.8-152.3 nm

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Chinese Journal of Chemical Physics 2008年第5期21卷 415-420页

作者： Ya-hua Hu Chen Zhen Jing-hua Dai Xiao-guo Zhou shi-lin liu Hefei National Laboratory for Physical Sciences at Microscale Department of Chemical Physics University of Science and Technology of China Hefei 230026 China

The absorption spectra of acetylene molecules was measured under jet-cooled conditions in the wavelength range of 142.8-152.3 nm, with a tunable and highly resolved vacuum ultraviolet （VUV） laser generated by two-photon resonant four wave difference frequency mixing processes. Due to the sufficient vibrational and rotational cooling effect of the molecular beam and the higher resolution VUV laser, the observed absorption spectra exhibit more distinct spectral features than the previous works measured at room temperature. The major three vibrational bands are assigned as a C-C symmetry stretching vibrational progress （v2=0.2） of the C^1Πu state of acetylene. The observed shoulder peak at 148,2 nm is assigned to the first overtone band of the trans-bending mode V4 of the C^1Πu state of acetylene. Additionally, the two components, 4^20（μ^1Π） and 4^20（k^1Πu）, are suggested to exhibit in the present absorption spectra, due to their Renner-Teller effect and transition selection rule. All band origins and bandwidths are obtained subsequently, and it is found that bandwidths are broadened and lifetimes decrease gradually with the excitation of vibration.

关键词： Acetylene Vacuum ultraviolet Absorption spectrum

Experimental and Density Functional Theory Calculation Studies on Raman and Infrared Spectra of 1,1＇-Binaphthyl-2,2＇-diamine

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Chinese Journal of Chemical Physics 2017年第1期30卷 7-15,I0001页

作者： Zhen-lin Zhang Wen-lou Wang shi-lin liu Dong-ming Chen Department of Chemical Physics University of Science and Technology of China Hefei 230026 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230029 China

The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman （UVRR） spectra of 1,1＇-binaphthyl-2,2＇-diamine （BINAM） were measured and analyzed. Density functional theory calculations were carried out to investigate its vibrational frequencies, infrared absorption, normal Raman, and near-resonance Raman intensities. The observed Raman and IR bands of BINAM were assigned with respect to the local vibrations of substituted 2-naphthylamine. Several Raman bands of BINAM were found selectively enhanced in the UVRR in comparison with the normal Raman spectrum. Possible excited state geometry distortion was discussed based on the resonance Raman intensity analysis.

关键词： 1,1'-Binaphthyl-2,2'-diamine Resonance Raman Infrared Density functional theory Molecular vibrations

Orientation and Structure of Ionic Liquid Cation at Air/[bmim][BF4] Aqueous Solution Interface

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Chinese Journal of Chemical Physics 2013年第5期26卷 569-575,I0004页

作者： Gang-hua Deng Xia Li You-qi Guo shi-lin liu Zhou Lu Yuan Guo Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Tech-nology of China Hefei 230026 China Beifing National Laboratory for Molecular Sciences State Key Laboratory of Molecular ReactionDynamics Institute of Chemistry Chinese Academy of Sciences Belting 100190 China Nanjing University of Aeronautics and Astronautics NanjinE 211205 China

The watermiscible room temperature ionic liquid 1butyl3methylimidazolium tetrafluorob orate （[bmim] [BF4]） is a model system for studying the interactions between ionic liquid and water molecules. In this work the orientational structure of the low concentrated aqueous solution of [bmim] [BF4] at the air/liquid interface was investigated by sum frequency gener ation vibrational spectroscopy. It has been found that at very low concentrations, the butyl chain exhibited a significant gauche defect, indicating a disordered conformation; and the cation ring oriented with a fairly small tilting angle at the surface. When the concentration increased, the cation ring tended to lie flat at the surface, and the gauche defects of the butyl chain decreased due to the intermolecular chainchain interactions and the consequent more ordered interfacial molecular arrangement. Additionally, the antisymmetric stretching mode in the PPP and SPS spectra exhibited a peak shift, showing that there exists more than one kind of orientation or chemical environment for the butyl CH3 group. These results may shed new light on understanding the surface behavior of watermiscible ionic liquids as well as the imidazolium based surfactants.

关键词： Sum frequency generation vibratinal spectroscopy Ionic liquid Aqueous solu-tion Interface orientation

Recent developments on anode materials for magnesium-ion batteries:a review

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Rare Metals 2021年第2期40卷 290-308页

作者： Qi Guo Wen Zeng shi-lin liu Yan-Qiong Li Jun-Yao Xu Jin-Xing Wang Yu Wang College of Materials Science and Engineering Chongqing UniversityChongqing400030China School of Electronic and Electrical Engineering Chongqing University of Arts and SciencesChongqing400030China Shanghai Urban Construction Vocational College Shanghai200438China

In recent years,there has been significant growth in the demand for secondary batteries,and researchers are increasingly taking an interest in the development of nextgeneration battery ***-ion batteries(MIBs)have been recognized as the optimal alternative to lithium-ion batteries(LIBs)due to their low cost,superior safety,and ***,research and development on rechargeable MIBs are still underway as some serious problems need to be *** of the most serious obstacles is the generation of an irreversible passivation layer on the surface of the Mg anode during *** addition to exploring new electrolytes for MIBs,alternative anode materials for MIBs might be an effective solution to this *** this review,the composition and working principle of MIBs have been *** addition,recent advances in the area of anode materials(metals and their alloys,metal oxides,and two-dimensional materials)available for MIBs and the corresponding Mg-storage mechanisms have also been ***,feasible strategies,including structural design,dimension reduction,and introduction of the second phase,have been employed to design high-performance MIB anodes.

关键词： Magnesium-ion batteries Energy storage systems Anode materials Metal oxides Two-dimensional materials

Effects of polymorphic form and particle size of SiO_(2)fillers on the properties of SiO_(2)-PEEK composites

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Journal of Advanced Dielectrics 2021年第4期11卷 56-63页

作者： Peng Jie Xue shi lin liu Jian Jiang Bian School of Material Science and Engineering Shanghai University 333Nanchen RoadShanghai 200444P.R.China

The effects of polymorphic form and particle size of SiO_(2)fillers on the dielectric,mechanical and thermal properties of SiO_(2)-Poly-etheretherketone(SiO_(2)-PEEK)composites were investigated in this *** low frequency(line a-cristobalite filled composite exhibits lower dielectric loss and mechanical strength,but larger thermal expansion coefficient and thermal conductivity,compared with the similar particle sized amorphous SiO_(2)filled *** crystalline a-quartz filled composite demonstrates the lowest mechanical strength and high-est dielectric *** increase in particle size of the spherical fused silica fillers decreases the dielectric loss,while increases the thermal conductivity of the *** flexural strength of the composite reaches the maximum value of 113 MPa when the particle size of spherical SiO_(2)filler is~10μ*** packing by combining optimal amounts of differently sized spherical fused silica fillers leads to a substantial improvement of mechanical strength(153MPa)coupled with reasonable dielectric and thermal properties due to the synergic effect(dielectric permittivity(ε_(r))=3.35,dielectric loss(tanδ)=1.63×10−3@10 GHz,thermal conductivity(l)=0.74 W/m*k(90°C),coefficient of thermal expansion(a)=23.6ppm/°C and relative density(r)=99.72%).

关键词： SiO_(2)/PEEK composites dielectric properties mechanical properties thermal conductivity thermal expansion

Vibrational Spectra and Adsorption of Trisiloxane Superspreading Surfactant at Air/Water Interface Studied with Sum Frequency Generation Vibrational Spectroscopy

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Chinese Journal of Chemical Physics 2008年第4期21卷 314-323页

作者： Jun Feng Dan Wu Jia Wen shi-lin liu Hong-fei Wang Hefei National Laboratory for Physical Sciences at Microscale Department of Chemical Physics University of Science and Technology of China Hefei 230025 China Beijing National Laboratory for Molecular Sciences State Key Laboratory of Molecular Reaction Dynamics Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

The C-H stretch vibrational spectra of the trisiloxane superspreading surfactant Silwet L-77 （（CH3）3Si- O-Si（CH3）（C3H6）（OCH2CH2）7-8OCH3）-O-Si（CH3）3） at the air/water interface are measured with the surface Sum Frequency Generation Vibrational Spectroscopy （SFG-VS）. The spectra are dominated with the features from the -Si-CH3 groups around 2905 cm^-1 （symmetric stretch or SS mode） and 2957 ^-1 （mostly the asymmetric stretch or AS mode）, and with the weak but apparent contribution from the -O-CH2- groups around 2880 ^-1 （symmetric stretch or SS mode）. Comparison of the polarization dependent SFG spectra below and above the critical aggregate or micelle concentration （CAC） indicates that the molecular orientation of the C-H related molecular groups remained unchanged at different surface densities of the Silwet L-77 surfactant. The SFG-VS adsorption isotherm suggested that there was no sign of Silwet L-77 bilayer structure formation at the air/water interface. The Gibbs adsorption free energy of the Silwet surfactant to the air/water interface is -42.2±0.8kcal/mol, indicating the unusually strong adsorption ability of the Silwet L-77 superspreading surfactant.

关键词： Trisiloxane surfactant Superspreader Surface adsorption Sum frequency generation vibrational spectroscopy

Raman Spectra of 1,2,4-Triazole-3-carboxylate Solution

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Chinese Journal of Chemical Physics 2019年第5期32卷 553-562页

作者： Xue-fei Chen Wei Fan Xiao-guo Zhou shi-lin liu Hefei National Laboratory for Physical Sciences at the Microscale iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Department of Chemical Physics University of Science and Technology of China Hefei 230026 China

Raman spectra of 1,2,4-triazole-3-carboxylate (TC- anion) and its ring-deprotonated deriva- tive (dpTC2- dianion) in aqueous solutions were measured respectively. The density func- tional theory calculations were performed using MN15 functional and PCM solvent model to investigate their structures, as well as the vibrational frequencies and Raman intensi- ties. With the aid of the calculated spectra, all the observed Raman bands of dpTC2- were clearly assigned, with taking into account the deuteration shifts. Moreover, various protonic tautomers of TC- anion were compared in the present theoretical calculations, and 2H- tautomer was found more stable. The experimental Raman spectrum of TC- solution was roughly consistent with the calculated spectrum of the monomeric 2H-tautomer of TC-, but some splits existed for a few bands when compared to the calculated spectra, which might be contributed by the hydrogen-bonding dimers of TC-.

关键词： 1,2,4-Triazole-3-carboxylate Raman spectrum Density functional theory Deprotonation