Ultrafast X-ray scattering offers a structural view of excited-state charge transfer
Ultrafast X-ray scattering offers a structural view of excited-state charge transfer
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超快 X 射线散射提供了激发态电荷转移的结构视图
DOI：
10.1073/pnas.2021714118
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Chang, Yu
中科院分区：
文献类型：
--
作者：
Yong, Haiwang;Xu, Xuan;Ruddock, Jennifer M.;Stankus, Brian;Carrascosa, Andrés Moreno;Zotev, Nikola;Bellshaw, Darren;Du, Wenpeng;Goff, Nathan;Chang, Yu
利用飞秒气相x射线散射技术，研究了N，N ' -二甲基哌嗪分子内电荷转移和分子结构的相关变化。这些分子在200nm处被光激发到3p态。在快速弛豫到3s态后，观察到与电荷转移相关的不同的电荷局域和电荷非局域物质。实验确定了这两种物质的分子结构，电子密度的重新分布由散射校正因子来解释。与基态相比，初始优势电荷定域态的碳-碳键较弱，并且重定向了一个甲基。随后的电荷转移到电荷离域状态，进一步拉长了碳碳键，形成了一个延长的1.634 Å键，并重新定位了第二个甲基。同时，氮原子和环碳原子之间的键长从平均1.505缩短到1.465 Å。实验确定了达到电荷局域和电荷非局域平衡的总电荷转移时间常数为3.0 ps。
Intramolecular charge transfer and the associated changes in molecular structure in N,N′-dimethylpiperazine are tracked using femtosecond gas-phase X-ray scattering. The molecules are optically excited to the 3p state at 200 nm. Following rapid relaxation to the 3s state, distinct charge-localized and charge-delocalized species related by charge transfer are observed. The experiment determines the molecular structure of the two species, with the redistribution of electron density accounted for by a scattering correction factor. The initially dominant charge-localized state has a weakened carbon–carbon bond and reorients one methyl group compared with the ground state. Subsequent charge transfer to the charge-delocalized state elongates the carbon–carbon bond further, creating an extended 1.634 Å bond, and also reorients the second methyl group. At the same time, the bond lengths between the nitrogen and the ring-carbon atoms contract from an average of 1.505 to 1.465 Å. The experiment determines the overall charge transfer time constant for approaching the equilibrium between charge-localized and charge-delocalized species to 3.0 ps.
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超快气相 X 射线散射的进展
DOI：
10.1088/1361-6455/abbfea
发表时间：
2020
期刊：
Journal of Physics B: Atomic, Molecular and Optical Physics
影响因子：
--
作者：
Brian Stankus;H. Yong;J. Ruddock;Lingyu Ma;Andrés Moreno Carrascosa;Nathan Goff;S. Boutet;Xuan Xu;Nikola Zotev;A. Kirrander;M. Minitti;P. Weber
通讯作者：
P. Weber
影响因子：
4.4
作者：
Kierspel, Thomas;Morgan, Andrew;Kuepper, Jochen
通讯作者：
Kuepper, Jochen
表征气相双原子分子的时间分辨 X 射线散射中的解离运动
影响因子：
2.9
作者：
Matthew R. Ware;J. Glownia;Noor Al;J. O’Neal;P. Bucksbaum
通讯作者：
P. Bucksbaum
影响因子：
56.9
作者：
Najafi, Ebrahim;Scarborough, Timothy D.;Zewail, Ahmed
通讯作者：
Zewail, Ahmed
影响因子：
4.4
作者：
Gudmundsdottir, Hildur;Zhang, Yao;Jonsson, Hannes
通讯作者：
Jonsson, Hannes