Structural Dynamics-Us最新文献_第6页

Time resolved transient circular dichroism spectroscopy using synchrotron natural polarization 同步加速器自然偏振的时间分辨瞬态圆二色光谱

IF 2.8 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2019-07-02 DOI: 10.1063/1.5120346

François Auvray, D. Dennetiere, A. Giuliani, F. Jamme, F. Wien, B. Nay, S. Zirah, F. Polack, C. Menneglier, B. Lagarde, J. Hirst, M. Réfrégiers

{"title":"Time resolved transient circular dichroism spectroscopy using synchrotron natural polarization","authors":"François Auvray, D. Dennetiere, A. Giuliani, F. Jamme, F. Wien, B. Nay, S. Zirah, F. Polack, C. Menneglier, B. Lagarde, J. Hirst, M. Réfrégiers","doi":"10.1063/1.5120346","DOIUrl":"https://doi.org/10.1063/1.5120346","url":null,"abstract":"Ultraviolet (UV) synchrotron radiation circular dichroism (SRCD) spectroscopy has made an important contribution to the determination and understanding of the structure of bio-molecules. In this paper, we report an innovative approach that we term time-resolved SRCD (tr-SRCD), which overcomes the limitations of current broadband UV SRCD setups. This technique allows accessing ultrafast time scales (down to nanoseconds), previously measurable only by other methods, such as infrared (IR), nuclear magnetic resonance (NMR), fluorescence and absorbance spectroscopies, and small angle X-ray scattering (SAXS). The tr-SRCD setup takes advantage of the natural polarization of the synchrotron radiation emitted by a bending magnet to record broadband UV CD faster than any current SRCD setup, improving the acquisition speed from 10 mHz to 130 Hz and the accessible temporal resolution by several orders of magnitude. We illustrate the new approach by following the isomer concentration changes of an azopeptide after a photoisomerization. This breakthrough in SRCD spectroscopy opens up a wide range of potential applications to the detailed characterization of biological processes, such as protein folding and protein-ligand binding.","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2019-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.5120346","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42006560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Hole dynamics in a photovoltaic donor-acceptor couple revealed by simulated time-resolved X-ray absorption spectroscopy 用模拟时间分辨X射线吸收光谱揭示光伏施主-受主对中的空穴动力学

IF 2.8 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2019-07-01 DOI: 10.1063/1.5097653

Khadijeh Khalili, L. Inhester, C. Arnold, R. Welsch, J. W. Andreasen, R. Santra

{"title":"Hole dynamics in a photovoltaic donor-acceptor couple revealed by simulated time-resolved X-ray absorption spectroscopy","authors":"Khadijeh Khalili, L. Inhester, C. Arnold, R. Welsch, J. W. Andreasen, R. Santra","doi":"10.1063/1.5097653","DOIUrl":"https://doi.org/10.1063/1.5097653","url":null,"abstract":"Theoretical and experimental methodologies that can characterize electronic and nuclear dynamics, and the coupling between the two, are needed to understand photoinduced charge transfer in molecular building blocks used in organic photovoltaics. Ongoing developments in ultrafast pump-probe techniques such as time-resolved X-ray absorption spectroscopy, using an X-ray free electron laser in combination with an ultraviolet femtosecond laser, present desirable probes of coupled electronic and nuclear dynamics. In this work, we investigate the charge transfer dynamics of a donor-acceptor pair, which is widely used as a building block in low bandgap block copolymers for organic photovoltaics. We simulate the dynamics of the benzothiadiazole-thiophene molecule upon photoionization with a vacuum ultraviolet (VUV) pulse and study the potential of probing the subsequent charge dynamics using time-resolved X-ray absorption spectroscopy. The photoinduced dynamics are calculated using on-the-fly nonadiabatic molecular dynamics simulations based on Tully's Fewest Switches Surface Hopping approach. We calculate the X-ray absorption spectrum as a function of time after ionization at the Hartree-Fock level. The changes in the time-resolved X-ray absorption spectrum at the sulfur K-edge reveal the ultrafast charge carrier dynamics in the molecule occurring on a femtosecond time scale. These theoretical findings anticipate that ultrafast time-resolved X-ray absorption spectroscopy using an X-ray probe in combination with a VUV pump offers a new approach to investigate the detailed dynamics of organic photovoltaic materials.","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.5097653","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46409219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Is radiation damage the limiting factor in high-resolution single particle imaging with X-ray free-electron lasers? 辐射损伤是x射线自由电子激光高分辨率单粒子成像的限制因素吗?

IF 2.8 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2019-07-01 DOI: 10.1063/1.5098309

C. Östlin, N. Tîmneanu, C. Caleman, A. V. Martin

引用次数: 11

Condensation of ground state from a supercooled phase in the Si(111)-(4 × 1) → (8 × 2)-indium atomic wire system Si(111)-(4 × 1)→(8 × 2)-铟原子线体系中过冷相的基态冷凝

IF 2.8 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2019-07-01 DOI: 10.1063/1.5111636

B. Hafke, T. Witte, D. Janoschka, P. Dreher, F. Meyer Zu Heringdorf, M. Horn-von Hoegen

引用次数: 2

Establishment of the Structural Equation of Motion 结构运动方程的建立