Hauf Christoph, Hernandez Salvador Antonio-Andres, Holtz Marcel, Woerner Michael, Elsaesser Thomas
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany.
Struct Dyn. 2019 Jan 30;6(1):014503. doi: 10.1063/1.5079229. eCollection 2019 Jan.
The coupled lattice and charge dynamics induced by phonon excitation in polycrystalline acetylsalicylic acid (aspirin) are mapped by femtosecond x-ray powder diffraction. The hybrid-mode character of the 0.9 ± 0.1 THz methyl rotation in the aspirin molecules is evident from collective charge relocations over distances of some 100 pm, much larger than the sub-picometer nuclear displacements. Oscillatory charge relocations around the methyl group generate a torque on the latter, thus coupling electronic and nuclear motions.
通过飞秒X射线粉末衍射绘制了多晶乙酰水杨酸（阿司匹林）中声子激发引起的耦合晶格和电荷动力学。阿司匹林分子中0.9±0.1太赫兹甲基旋转的混合模式特征从约100皮米距离上的集体电荷重新分布中明显可见，这比亚皮米级的核位移大得多。甲基周围的振荡电荷重新分布在后者上产生一个扭矩，从而耦合电子和核运动。
