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Tailoring On-Surface Molecular Reactions and Assembly through Hydrogen-Modified Synthesis: From Triarylamine Monomer to 2D Covalent Organic Framework

arXiv

引用

arXiv 2022年

作者： Enderson, Zachery A. Murali, Harshavardhan Dasari, Raghunath R. Dai, Qingqing Li, Hong Parker, Timothy C. Brédas, Jean-Luc Marder, Seth R. First, Phillip N. School of Physics Georgia Institute of Technology AtlantaGA30332 United States School of Chemistry and Biochemistry Georgia Institute of Technology AtlantaGA30332 United States Department of Chemistry and Biochemistry The University of Arizona TucsonAZ85721 United States University of Colorado Boulder Renewable and Sustainable Energy Institute Department of Chemical and Biological Engineering Department of Chemistry Materials Science and Engineering Program BoulderCO80303 United States National Renewable Energy Laboratory Chemistry and Nanoscience Center GoldenCO80401 United States

Relative to conventional wet-chemical synthesis techniques, on-surface synthesis of organic networks in ultrahigh vacuum has few control parameters. The molecular deposition rate and substrate temperature are typically the only synthesis variables to be adjusted dynamically. Here we demonstrate that reducing conditions in the vacuum environment can be created and controlled without dedicated sources—relying only on backfilled hydrogen gas and ion gauge filaments—and can dramatically influence the Ullmann-like on-surface reaction used for synthesizing two-dimensional covalent organic frameworks (2D COFs). Using tribromo dimethylmethylene-bridged triphenylamine ((Br3)DTPA) as monomer precursors, we find that atomic hydrogen (H∙) blocks aryl-aryl bond formation to such an extent that we suspect this reaction may be a factor in limiting the ultimate size of 2D COFs created through on-surface synthesis. Conversely, we show that control of the relative monomer and hydrogen fluxes can be used to produce large self-assembled islands of monomers, dimers, or macrocycle hexamers, which are of interest in their own right. On-surface synthesis of oligomers, from a single precursor, circumvents potential challenges with their protracted wet-chemical synthesis and with multiple deposition sources. Using scanning tunneling microscopy and spectroscopy (STM/STS), we show that changes in the electronic states through this oligomer sequence provide an insightful view of the 2D-COF (synthesized in the absence of atomic hydrogen) as the endpoint in an evolution of electronic structures from the monomer. © 2022, CC BY-NC-SA.

关键词： Monomers

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Crossed Beam Experiment on the Validity of Born-Oppenheimer Approximation in Cl(2P)+D2→DCl+D Reaction

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Chinese Journal of chemical physics 2020年第2期33卷 135-138,I0002页

作者： Yu-run Xie Yu-feng Wang Wei Wang Tao Wang Dong-xu Dai Chun-lei Xiao Xue-ming Yang Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China School of Physical Science&Technology ShanghaiTech UniversityShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China College of Science Southern University of Science and TechnologyShenzhen 518055China

The reaction of chlorine atom Cl(2P)(Cl(2P3/2)and Cl^*(2P1/2))with D2 was investigated at collision energy from 4.5 kcal/mol to 6.5 kcal/mol with a high-resolution crossed molecular beam apparatus using the technique of D-atom Rydberg tagging *** contribution from the spin-orbit excited reaction Cl^*(2P1/2)+D2,which is prohibited by Born-Oppenheimer(BO)approximation,was ***-energy dependence of differential cross sections(DCSs)near the backward scattering direction was *** BOforbidden reaction Cl^*+D2 was found to be dominant at lower collision *** collision energy increases,reactivity of BO-allowed reaction Cl+D2 increases much faster than that of BO-forbidden reaction and becomes dominant at higher collision *** experiment indicates that the additional energy of spin-orbit excitation in Cl^*facilitates BO-forbidden reaction to pass through the barrier at lower collision energy,while BO approximation is still valid at collision energy near and above the reaction *** tendency of reactivity of Cl/Cl^*+D2 is similar to the isotopic reaction of Cl/Cl^*+H2.

关键词： Spin-orbit state Born-Oppenheimer approximation Crossed beam experiment

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Revisiting the Transit Timing and Atmosphere Characterization of the Neptune-mass Planet HAT-P-26 b

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Astronomical Journal 2023年第6期166卷 223页

作者： A-Thano, Napaporn Awiphan, Supachai Jiang, Ing-Guey Kerins, Eamonn Priyadarshi, Akshay McDonald, Iain Joshi, Yogesh C. Chulikorn, Thansuda Hayes, Joshua J. C. Charles, Stephen Huang, Chung-Kai Rattanamala, Ronnakrit Yeh, Li-Chin Dhillon, Vik S Department of Physics Institute of Astronomy National Tsing-Hua University Hsinchu 30013 Taiwan National Astronomical Research Institute of Thail 260 Moo 4 Donkaew Mae Rim Chiang Mai 50180 Thailand Jodrell Bank Centre for Astrophysics University of Manchester Oxford Road Manchester M13 9PL United Kingdom Department of Physical Sciences The Open University Walton Hall Milton Keynes MK7 6AA United Kingdom Aryabhatta Research Institute of Observational Sciences (ARIES) Manora Peak Nainital 263001 India Department of Physics Faculty of Science Chulalongkorn University 254 Phayathai Road Pathumwan Bangkok 10330 Thailand Institute of Astronomy and Astrophysics Academia Sinica No.1 Sec. 4 Roosevelt Road Taipei 10617 Taiwan PhD Program in Astronomy Department of Physics and Materials Science Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Department of Physics and General Science Faculty of Science and Technology Nakhon Ratchasima Rajabhat University Nakhon Ratchasima 30000 Thailand Institute of Computational and Modeling Science National Tsing-Hua University Hsinchu 30013 Taiwan Department of Physics and Astronomy University of Sheffield Sheffield S3 7RH United Kingdom Instituto de Astrofísica de Canarias La Laguna Tenerife E-38205 Spain

We present a transit-timing variation (TTV) and planetary atmosphere analysis of the Neptune-mass planet HAT-P-26 b. We present a new set of 13 transit light curves from optical ground-based observations and combine them with light curves from the Wide Field Camera 3 on the Hubble Space Telescope, the Transiting Exoplanet Survey Satellite, and previously published ground-based data. We refine the planetary parameters of HAT-P-26 b and undertake a TTV analysis using 33 transits obtained over seven years. The TTV analysis shows an amplitude signal of 1.98 ± 0.05 minutes, which could result from the presence of an additional ∼0.02 M _Jup planet at a 1:2 mean-motion resonance orbit. Using a combination of transit depths spanning optical to near-infrared wavelengths, we find that the atmosphere of HAT-P-26 b contains 2.4 − 1.6 + 2.9 % H₂O with a derived temperature of 590 − 50 + 60 K. © 2023. The Author(s). Published by the American Astronomical Society.

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Shifting the learning gears: Redesigning a project-based course on soft matter through the perspective of constructionism

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physical Review physics Education Research 2020年第2期16卷 020147-020147页

作者： Elon Langbeheim Ariel Abrashkin Ariel Steiner Haim Edri Samuel Safran Edit Yerushalmi Graduate Program of Science and Technology Education Ben-Gurion University 8410501 Beer-Sheva Israel Department of Science Teaching Weizmann Institute of Science 7610001 Rehovot Israel Department of Chemical and Biological Physics Weizmann Institute of Science 7610001 Rehovot Israel

This article describes the redesign of a project-based course on soft and biological materials to include computational modeling. Including the construction of computational models in the course is described as a shift from constructivism—a theory that characterizes the development of formal reasoning, to constructionism—a theory that focuses on learning while constructing artifacts. This shift ameliorated two drawbacks in the original course: the limited conceptualization of entropy resulting from an unproductive use of the disorder metaphor, and the dependence of most students on the teacher for writing theoretical explanations for their final papers. In the redesigned curriculum, computer simulations provide concrete dynamic representations that students can draw upon for developing nuanced, formal reasoning on entropy and the 2nd law of thermodynamics. In addition, core computational models act as a flexible web that can be extended and modified, and allow a significant proportion of the students to build theoretical models on their own. We conclude that while the new design reflects a shift towards constructionism, we did not adopt a fully constructionist approach, rather a blend of constructivist and constructionist approaches.

关键词： Entropy Instructional materials development

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Optimizing the Intermediates Adsorption by Manipulating the Second Coordination Shell of Ir Single Atoms for Efficient Water Oxidation

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Angewandte Chemie 2024年第44期136卷

作者： Jie Wei Hua Tang Yan Liu Guiliang Liu Li Sheng Minghui Fan Yiling Ma Zhirong Zhang Jie Zeng Hefei National Research Center for Physical Sciences at the Microscale CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes Department of Chemical Physics University of Science and Technology of China Hefei Anhui 230026 P. R. China Nano Science and Technology Institute University of Science and Technology of China Suzhou 215123 China School of Chemistry & Chemical Engineering Anhui University of Technology Ma'anshan Anhui 243002 P. R. China

The precise regulation of single-atom catalysts (SACs) with the desired local chemical environment is vital to elucidate the relationship between the SACs structure and the catalytic performance. The debate on the effect of the local coordination environment is quite complicated even for the SACs with the same composition and chemical nature, calling for increased attention on the regulation of the second coordination shell. For oxide-supported SACs, it remains a significant challenge to precisely manipulate the second coordination shell of single atoms supported on oxides due to the structural robustness of oxides. Here, Ir single atoms were anchored on NiO supports via different bonding strategies, resulting in the diverse Ir−O−Ni coordination numbers for Ir sites. Specifically, Ir 1 /NiO, Ir 1 −NiO, and Ir 1 @NiO SACs with increasing Ir−O−Ni coordination numbers of 3, 4, and 5 were synthesized, respectively. We found that the activity of the three samples towards oxygen evolution reaction (OER) exhibited a volcano-shaped relationship with the Ir−O−Ni coordination number, with Ir 1 −NiO showing the lowest overpotential of 225 mV at 10 mA cm −2 . Mechanism investigations indicate that the moderate coordination number of Ir−O−Ni in Ir 1 −NiO creates the higher occupied Ir d z2 orbital, weakening the adsorption strength for *OOH intermediates and thereby enhancing the OER activity.

关键词： Volcano-type relationship single-atom catalysts second coordination shell oxygen evolution reaction

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Synthesis of α,ω-End Functionalized Polydienes: Allylic-Bearing Heteroleptic Aluminums for Selective Alkylation and Transalkylation in Coordinative Chain Transfer Polymerization

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Angewandte Chemie 2023年第5期136卷

作者： Dr. Pibo Liu Xiao Yang Dr. He Li Dr. Songbo Zhang Prof. Yanming Hu Prof. Guangyuan Zhou Prof. Nikos Hadjichristidis Division of Energy Materials Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian Liaoning 116023 China Physical Sciences and Engineering Division KAUST Catalysis Center Chemistry Program Polymer Synthesis Laboratory King Abdullah University of Science and Technology (KAUST) Thuwal 23955 Kingdom of Saudi Arabia

There are still challenges in the preparation of difunctional stereoregular polydienes, especially for the construction of initiating chain-end functionalization. Coordinative chain transfer polymerization (CCTP) provides a way to achieve the goal but usually requires sophisticated functionalized catalysts as well as expensive chain transfer agents (CTAs). In this work, heteroleptic aluminum with oligo(dienyl) substituents (oligo-Al agents) were readily prepared by living anionic polymerization (LAP) technique. The oligo-Al agents used in Nd-mediated CCTPs of dienes exhibit highly selective alkylation and transalkylation features. Kinetics and transfer efficiency studies using 1 H NMR, 13 C NMR, 1 H- 13 C HSQC, and Dosy NMR analyses revealed that the resulting polydienes possess substituents at the initiating chain-end that have transferred from the oligo-Al agents. The functionalization efficiency of the initiating chain-end is up to 99 %, and the molar mass regulation efficiency of heteroleptic aluminum is higher than that of the traditional CTA Al i Bu 2 H (0.608 vs. 0.410). Based on the experimental results and density functional theory (DFT) calculations, we propose a mechanism in which allylic-Al acts as an efficient alkylating moiety in catalyst preformation and also as an effective transfer agent in polymerization. Taking advantage of these features, di-functionalized polyisoprene, polybutadiene, and poly(isoprene-co-butadiene) can be facilely synthesized.

关键词： Aluminum Chain Transfer Polymerization End-Functionalization Neodymium Polydiene

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Unraveling the Orbital physics in a Canonical Orbital System KCuF3

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physical Review Letters 2021年第10期126卷 106401-106401页

作者： Jiemin Li Lei Xu Mirian Garcia-Fernandez Abhishek Nag H. C. Robarts A. C. Walters X. Liu Jianshi Zhou Krzysztof Wohlfeld Jeroen van den Brink Hong Ding Ke-Jin Zhou Diamond Light Source Harwell Campus Didcot OX11 0DE United Kingdom Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China Institute for Theoretical Solid State Physics IFW Dresden Helmholtzstrasse 20 D-01069 Dresden Germany H. H. Wills Physics Laboratory University of Bristol Bristol BS8 1TL United Kingdom School of Physical Science and Technology ShanghaiTech University Shanghai 201210 China The Materials Science and Engineering Program Mechanical Engineering University of Texas at Austin Austin Texas 78712 USA Institute of Theoretical Physics Faculty of Physics University of Warsaw Pasteura 5 PL-02093 Warsaw Poland Institute for Theoretical Physics and Würzburg-Dresden Cluster of Excellence ct.qmat TU Dresden 01069 Dresden Germany

We explore the existence of the collective orbital excitations, orbitons, in the canonical orbital system KCuF3 using the Cu L3-edge resonant inelastic x-ray scattering. We show that the nondispersive high-energy peaks result from the Cu2+ dd orbital excitations. These high-energy modes display good agreement with the ab initio quantum chemistry calculation, indicating that the dd excitations are highly localized. At the same time, the low-energy excitations present clear dispersion. They match extremely well with the two-spinon continuum following the comparison with Müller ansatz calculations. The localized dd excitations and the observation of the strongly dispersive magnetic excitations suggest that the orbiton dispersion is below the resolution detection limit. Our results can reconcile with the strong local Jahn-Teller effect in KCuF3, which predominantly drives orbital ordering.

关键词： Orbital order Mott insulators Crystal-field theory Resonant inelastic x-ray scattering

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Competing electronic states emerging on polar surfaces

arXiv

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arXiv 2022年

作者： Reticcioli, Michele Wang, Zhichang Schmid, Michael Wrana, Dominik Boatner, Lynn A. Diebold, Ulrike Setvin, Martin Franchini, Cesare University of Vienna Faculty of Physics Center for Computational Materials Science Vienna Austria Institute of Applied Physics Technische Universität Wien Vienna Austria State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen China Department of Surface and Plasma Science Faculty of Mathematics and Physics Charles University Prague 8180 00 Czech Republic Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge United States Dipartimento di Fisica e Astronomia Università di Bologna Bologna40127 Italy

Excess charge on polar surfaces of ionic compounds is commonly described by the two-dimensional electron gas (2DEG) model, a homogeneous distribution of charge, spatially-confined in a few atomic layers. Here, by combining scanning probe microscopy with density functional theory calculations, we show that excess charge on the polar TaO2 termination of KTaO3(001) forms more complex electronic states with different degrees of spatial and electronic localization: charge density waves (CDW) coexist with strongly-localized electron polarons and bipolarons. These surface electronic reconstructions, originating from the combined action of electron-lattice interaction and electronic correlation, are energetically more favorable than the 2DEG solution. They exhibit distinct spectroscopy signals and impact on the surface properties, as manifested by a local suppression of ferroelectric distortions. Controlling the degree of charge ordering and the transition from ferroelectric to paraelectric states could be of great benefit for the generation and transport of carriers in electronic applications. Copyright © 2022, The Authors. All rights reserved.

关键词： Electronic states

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Perovskite-transition metal dichalcogenides heterostructures: recent advances and future perspectives

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Opto-Electronic science 2022年第8期1卷 1-40页

作者： Ahmed Elbanna Ksenia Chaykun Yulia Lekina Yuanda Liu Benny Febriansyah Shuzhou Li Jisheng Pan Ze Xiang Shen Jinghua Teng Institute of Materials Research and Engineering Agency for ScienceTechnology and Research(A*STAR)2 Fusionopolis WaySingapore 138634Singapore Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological University50 Nanyang AvenueSingapore 637371Singapore Interdisciplinary Graduate Program Energy Research Institute@NTUNanyang Technological University50 Nanyang AvenueSingapore 639798Singapore The Photonics Institute and Center for Disruptive Photonic Technologies Nanyang Technological University50 Nanyang AvenueSingapore 639798 Singapore School of Materials Science and Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore Berkeley Educational Alliance for Research in Singapore(BEARS) Ltd.1 CREATE WaySingapore 138602Singapore.

Transition metal dichalcogenides(TMDs)and perovskites are among the most attractive and widely investigated semiconductors in the recent *** are promising materials for various applications,such as photodetection,solar energy harvesting,light emission,and many *** these materials to form heterostructures can enrich the already fascinating properties and bring up new phenomena and *** in this field is growing rapidly in both fundamental studies and device ***,we review the recent findings in the perovskite-TMD heterostructures and give our perspectives on the future development of this promising *** fundamental properties of the perovskites,TMDs,and their heterostructures are discussed first,followed by a summary of the synthesis methods of the perovskites and TMDs and the approaches to obtain high-quality *** attention is paid to the TMD-perovskite heterostructures that have been applied in solar cells and photodetectors with notable performance *** through our analysis,we propose an outline on further fundamental studies and the promising applications of perovskite-TMD heterostructures.

关键词： transition metal dichalcogenides perovskites heterostructures photodetectors solar cells 2D materials

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In Situ Electric-Field Control of THz Nonreciprocal Directional Dichroism in the Multiferroic Ba2CoGe2O7

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physical Review Letters 2021年第15期127卷 157201-157201页

作者： J. Vít J. Viirok L. Peedu T. Rõõm U. Nagel V. Kocsis Y. Tokunaga Y. Taguchi Y. Tokura I. Kézsmárki P. Balla K. Penc J. Romhányi S. Bordács Department of Physics Budapest University of Technology and Economics 1111 Budapest Hungary Institute of Physics ASCR Na Slovance 2 182 21 Prague 8 Czech Republic Faculty of Nuclear Science and Physical Engineering Czech Technical University Břehová 7 115 19 Prague 1 Czech Republic National Institute of Chemical Physics and Biophysics Akadeemia tee 23 12618 Tallinn Estonia RIKEN Center for Emergent Matter Science (CEMS) Wako 351-0198 Japan Department of Advanced Materials Science University of Tokyo Kashiwa 277-8561 Japan Department of Applied Physics and Tokyo College University of Tokyo Tokyo 113-8656 Japan Experimental Physics V Center for Electronic Correlations and Magnetism University of Augsburg 86135 Augsburg Germany Institute for Solid State Physics and Optics Wigner Research Centre for Physics P.O. Box. 49 H-1525 Budapest Hungary Department of Physics and Astronomy University of California Irvine 4129 Frederick Reines Hall Irvine California 92697 USA Hungarian Academy of Sciences Premium Postdoctor Program 1051 Budapest Hungary

Nonreciprocal directional dichroism, also called the optical-diode effect, is an appealing functional property inherent to the large class of noncentrosymmetric magnets. However, the in situ electric control of this phenomenon is challenging as it requires a set of conditions to be fulfilled: Special symmetries of the magnetic ground state, spin excitations with comparable magnetic- and electric-dipole activity, and switchable electric polarization. We demonstrate the isothermal electric switch between domains of Ba2CoGe2O7 possessing opposite magnetoelectric susceptibilities. Combining THz spectroscopy and multiboson spin-wave analysis, we show that unbalancing the population of antiferromagnetic domains generates the nonreciprocal light absorption of spin excitations.

关键词： Magnetoelectric effect Magnons Optical & microwave phenomena Antiferromagnets Multiferroics

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