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The superiority of nonconjugated structures in fluorescence:through-space ***-bond charge transfer

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Science China chemistry 2024年第9期67卷 3121-3130页

作者： Weihao Tu Zuping Xiong Lei wang Jianyu Zhang Jing zhi Sun Haoke Zhang Ben zhong Tang MOE key laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310058China Zhejiang-Israel Joint laboratory of Self-Assembling Functional Materials ZJU-Hangzhou Global Scientific and Technological Innovation CenterZhejiang UniversityHangzhou 311215China Centre of Healthcare Materials Shaoxing InstituteZhejiang UniversityShaoxing 312000China Department of chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and ReconstructionThe Hong Kong University of Science and TechnologyHong Kong 999077China School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhen(CUHK-Shenzhen)Guangzhou 518172China

Constructing charge transfer(CT)state by introducing donor(D)and acceptor(A)is an efficient strategy to regulate the photophysical properties of luminescent *** CT-type luminophores are built onπ-conjugated fused-ring structures,which always show hybrid CT/locally excited(LE)states and luminescence quenching effect in the aggregate *** this work,eight conjugated biphenyl(BP)and nonconjugated diphenylmethane(DPM)derivatives with different donors and acceptors are synthesized to investigate the CT *** photophysical characterization and theoretical calculation demonstrate that the through-space CT(TSCT)in nonconjugated DA-DPM exhibit superior photophysical performance than the conjugated DA-BP with through-bond CT(TBCT),the main manifestations are as follows:(1)TSCT luminophores produce longer maximum emission wavelength(λ_(em))than the corresponding TBCT *** example,the longest λ_(em)of DMA-CN-DPM(DMA,dimethylamino)is 621 nm but the corresponding λ_(em)of DMA-CN-BP is only 480 nm.(2)TSCT-based DA-DPM demonstrates more sensitive responsiveness to environmental stimuli such as temperature and polarity.(3)Complete separation of the the highest occupied molecular orbital(HOMO)and the lowest unoccupied molecular orbital(LUMO)distribution exists in all kinds of conformation of DA-DPM,which was hard to realize in conjugated DA-BP.

关键词： through-space charge transfer through-space conjugation clusteroluminescence diphenylmethane

Structures and stability of isomers of[C,N,N,P]system

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Science China chemistry 2005年第5期48卷 415-423页

作者： KAN Wei1,2, zhong Hua1, YU Haitao1, FU Honggang1,3 & SUN Jiazhong1,3 1. School of chemistry and Materials Science, Heilongjiang university, Harbin 150080, China 2. School of chemistry and Chemical Engineering, Qiqihar university, Qiqihar 161006, China 3. state key laboratory of theoretical and computational chemistry, institute of theoretical chemistry, jilin university, changchun 130023, China School of chemistry and Materials Science Heilongjiang University Harbin China School of chemistry and Chemical Engineering Qiqihar University Qiqihar China jilin university Changchun China

Nine isomers, twenty transition states, and some relative dissociation fragments of [C,N,N,P] system were located at the B3LYP/6-311G(d) and QCISD(t)/6-311+G(2df) (single-point) levels of theory, and the isomerization, structures, and stability of these obtained isomers were suggested. The results indicate that four nonlinear chainlike isomers NCNP, NCPN, CNPN, and CNNP with 2A′ electronic state are kinetically stable. Other isomers are kinetically unstable to-wards isomerization or dissociation because of the corresponding smaller reaction barriers. Furthermore, calculated vibrational frequencies, rotational constants, dipole moments, the first adiabatic ionization energies, and adiabatic electron affinities of the four isomers may provide some theoretical information that is helpful for identifying their existence in future laboratory and interstellar investigations. The results are also compared with [Si,N,N,P] system.

关键词： potential energy surface, [C,N,N,P] system, isomerization, kinetic stability.

Reactivity of Neutral Al14 Cluster with Water

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Reactivity of Neutral Al14 Cluster with Water

Aromatic Superhalogen Anion:N5LiN5-

中国化学会第六届全国结构化学学术会议

作者： Na Hou,Ying Li,Di Wu~*,zhi-Ru Li institute of theoretical chemistry,state key laboratory of theoretical and computational chemistry,jilin university,changchun,130023

Superatom clusters which can exhibit behaviors reminiscent of atoms in the periodic table may have synthetic utility,and represent potential building blocks for the assembly of novel,nanostructured materials. Consequently,the concept of superatoms has attracted considerable interests over the past couple of *** has been demonstrated that the Al cluster can behave as an alkaline earth metal-like

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Aromatic Superhalogen Anion:N5LiN5-

Dissipative particle dynamics study on the interfaces in incompatible A/B homopolymer blends and with their block copolymers

中国化学会第六届全国结构化学学术会议

作者： Dan Hou,Ying Li,Di Wu~*,zhi-Ru Li institute of theoretical chemistry,state key laboratory of theoretical and computational chemistry,jilin university,changchun,130023

Atomic clusters with suitable size and composition may behave as certain atoms in the Periodic Table and such clusters can be described as *** famous subset of superatoms of interest is superhalogens with higher electron affinities(EAs) than those of halogen *** 1997,Gutseva and his co-workers reported the geometries and superhalogen characteristics for the neutral MX and ionic MX

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Dissipative particle dynamics study on the interfaces in inc...

Polaron interfacial entropy as a route to high thermoelectric performance in DAE-doped PEDOT:PSS films

中国化学会第九届全国量子化学学术会议

作者： Hu-Jun Qian, zhong-Yuan Lu, Li-Jun Chen, Ze-Sheng Li, Chia-Chung Sun state key laboratory of theoretical and computational chemistry, institute of theoretical chemistry, jilin university, changchun 130023, China

＜正＞Dissipative particle dynamics （DPD） [1], a simulation technique appropriate at mesoscopic scales, has been applied to investigate the interfaces in immiscible binary A/B homopolymer blends and in the ternary systems with their block copolymers. To measure the surface tension in the present simulations, the difference between the normal and the transversal components of the pressure was integrated across the interface. We calculate the normal and transversal components of the pressure

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National Science Review 2024年第3期11卷 259-270页

作者： Jiajia Zhang Caichao Ye Genwang Wei Liang Guo Yuhang Cai zhi Li Xinzhi Wu Fangyi Sun Qikai Li Yupeng wang Huan Li Yuchen Li Shuaihua wang Wei Xu Xuefeng Guo Wenqing Zhang Weishu Liu Department of Materials Science and Engineering Southern University of Science and Technology Academy for Advanced Interdisciplinary Studies and Guangdong Provincial key laboratory of computational Science and Material Design Southern University of Science and Technology Department of Mechanical and Energy Engineering Southern University of Science and Technology Beijing National laboratory for Molecular Sciences Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences College of chemistry and Molecular Engineering National Biomedical Imaging Centre Peking University Guangdong Provincial key laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology

Enhancing the thermoelectric transport properties of conductive polymer materials has been a long-term challenge, in spite of the success seen with molecular doping strategies. However, the strong coupling between the thermopower and the electrical conductivity limits thermoelectric performance. Here, we use polaron interfacial occupied entropy engineering to break through this intercoupling for a PEDOT:PSS(poly（3,4-ethylenedioxythiophene）-poly（4-styrenesulfonate）) thin film by using photochromic diarylethene（DAE） dopants coupled with UV-light modulation. With a 10-fold enhancement of the thermopower from 13.5 μV K-1to 135.4 μV K-1and almost unchanged electrical conductivity, the DAE-doped PEDOT:PSS thin film achieved an extremely high power factor of 521.28 μW m-1K-2from an original value of 6.78 μW m-1K-2. The thermopower was positively correlated with the UV-light intensity but decreased with increasing temperature, indicating resonant coupling between the planar closed DAE molecule and PEDOT. Both the experiments and theoretical calculations consistently confirmed the formation of an interface state due to this resonant coupling. Interfacial entropy engineering of polarons could play a critical role in enhancing the thermoelectric performance of the organic film.

关键词： thermoelectric PEDOT: PSS interfacial occupied entropy resonant coupling UV-light modulation

Improve titanate reduction by electro-deoxidation of Ca_(3)Ti_(2)O_(7) precursor in molten CaCl_(2)

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International Journal of Minerals,Metallurgy and Materials 2020年第12期27卷 1618-1625页

作者： Dong wang Sheng Pang Chun-yue Zhou Yan Peng zhi wang Xu-zhong Gong key laboratory of Green Process and Engineering National Engineering Laboratory for Hydrometallurgical Cleaner Production TechnologyInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341119China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China School of chemistry and Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

The low O^(2-)diffusion rate in the electro-deoxidation of titanium containing compounds by either the OS process or the FFC process leads to a low reaction speed and a low current *** this study,Ca_(3)Ti_(2)O_(7) was used as a precursor to improve the reduction speed of *** of the greater number of"diffusion channels"created in cathode as Ca^(2+) liberates from Ca_(3)Ti_(2)O_(7) precursor in the electrodeoxidation process,the O^(2-)diffusion rate was improved significantly by using Ca_(3)Ti_(2)O_(7) instead of CaTiO3 as *** constant voltage electrolysis(3.2 V)confirms that Ca_(3)Ti_(2)O_(7) and CaTiO3 are reduced simultaneously because of their similar crystal ***,the reduction area of Ca_(3)Ti_(2)O_(7) spreads much faster than that of CaTiO3,indicating a difference in the O^(2-) diffusion *** voltage cyclic voltammetry(CV)and theoretical analysis of the crystal structure were also conducted to compare the differences between Ca_(3)Ti_(2)O_(7) and *** results indicate that using a precursor with a greater number of soluble cations,titanium reduction speed can be greatly improved in the electro-deoxidation ***,a new electrolysis method for converting and recycling excess CaO from the Ca_(3)Ti_(2)O_(7) precursor was proposed.

关键词： calcium titanate Ca_(3)Ti_(2)O_(7) molten calcium chloride solid-state reaction reaction speed

Large-scale carambola-like V_(2)O_(5) nanoflowers arrays on microporous reed carbon as improved electrochemical performances lithium-ion batteries cathode

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Journal of Energy chemistry 2020年第12期29卷 388-395页

作者： Hua Tan Xin zhi Yu Kai Huang Jianxin zhong Bingan Lu School of Physics and Optoelectronics Hunan Institute of Advanced Sensing and Information TechnologyXiangtan UniversityXiangtan 41U05HunanChina School of Physics and Electronics State Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyHunan Provincial Key Laboratory of Multi-electron based Energy Storage DevicesHunan UniversityChangsha 410083HunanChina

To search for new cathode materials with high energy density of Lithium-ion batteries(LIBs) is one of the most challenging issues. Vanadium pentoxide(V2 O5) with high theoretical specific capacity is believed to be a promising candidate for the next generation cathode materials, yet still suffers from low lithium ion diffusion coefficient and poor electronic conductivity resulting in low cycling life and poor rate performances. Here, we report new large-scale carambola-like V2 O5 nanoflowers arrays anchored on microporous reed carbon as high performances LIBs cathode. Each individual pore space of the microporous reed carbon is like a hexagonal cylinder, and the area of each carbon wall is more than103 um2, which is favorable for the growth of V2 O5 nanostructure arrays. After hydrothermal, the largescale carambola-like V2 O5 nanoflowers arrays can directly grow on the surface of microporous *** to the novel composite structures, the V2 O5 nanoflowers arrays@microporous carbon stabilizes at273 mA h g^(-1) after 100 cycles at 0.2 C. When cycling at 1.0 C over 500 cycles, the capacity still maintains at 180 mAh g^(-1). The demonstrated approach in this work paves the way for the development of high rate capability and excellent cycling stability V2 O5-based cathode materials.

关键词： V_(2)O_(5) Cathode Reed carbon Microporous Lithium-ion batteries

Investigation of the room-temperature photoelectron spectroscopy of type-Ⅱ Weyl semimetal candidate WTe_(2)

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钨科技(英文) 2023年第3期5卷 350-356页

作者： Jian-yang Ding Zheng-Tai Liu Zhe Huang zhi-Cheng Jiang Yi-Chen yang zhong-Hao Liu Ji-Shan Liu Yan-Feng Guo Da-Wei Shen state key laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

Layered transition metal dichalcogenides have novel physical properties and great potential for *** them,WTe2,which has an extremely large unsaturated magnetoresistance and is theoretically predicted to be a type-Ⅱ Weyl semimetal,has been extensively ***,we systematically probe the electronic structure of WTe_(2) at room temperature using high-resolution angle-resolved photoelectron spectroscopy(ARPES).We find that temperature-driven chemical potential shift and Lifshitz transition,which is equivalent to low-energy band structures shift downward by around 50 meV,compared to the results at low *** ARPES experimental results match well with previous theoretical calculations,implying the possible existence of type-Ⅱ Weyl points near the Γ-X ***,as expected,there exists a dominantly electron-like Fermi surface instead of the one with compensated electrons and ***,our ARPES results show that the flat band(FB) lying below the Fermi level(EF) becomes closer to the Fermi level at room temperature,which might start to dominate the transport behavior and lead to the disappearance of the unsaturated giant magnetoresistance *** findings not only reveal the electronic structure features of WTe_(2) at room temperature,but also provide new insights into the development of room-temperature topological quantum devices.

关键词： Weyl semimetal Electronic structure ARPES Compensation effect