普林斯顿大学Gregory D. Scholes课题组揭示了超快电子转移反应中振动波包的相互作用。 该项研究成果发表在2020年12月7日出版的《自然—化学》。

电子转移反应促进了生物和化学中的能量传递和光催化过程。最近的研究表明，分子振动可以使某些电子转移反应的剧烈加速，并通过抑制和增强反应路径来控制它。

该文中，研究人员通过超快光谱实验和量子动力学模拟实验揭示了量子振动如何参与电子转移反应。研究人员观察到弹道电子转移（~30fs）沿着由高频促进振动组成的反应坐标系。由于电子转移反应，当沿着另一个振动坐标系时系统突然失去平衡。这导致（通过电子转移反应，而不是激光脉冲）在与反应产物相关的模式下沿着第二个反应坐标产生新的振动相干。

这些结果解决了一个由多个振动坐标组成的复杂反应轨迹，该轨迹像一系列棘轮一样，逐渐减少反应物状态的重现。

附：英文原文

Title: Interplay of vibrational wavepackets during an ultrafast electron transfer reaction

Author: Shahnawaz Rafiq, Bo Fu, Bryan Kudisch, Gregory D. Scholes

Issue&Volume: 2020-12-07

Abstract: Electron transfer reactions facilitate energy transduction and photoredox processes in biology and chemistry. Recent findings show that molecular vibrations can enable the dramatic acceleration of some electron transfer reactions, and control it by suppressing and enhancing reaction paths. Here, we report ultrafast spectroscopy experiments and quantum dynamics simulations that resolve how quantum vibrations participate in an electron transfer reaction. We observe ballistic electron transfer (~30fs) along a reaction coordinate comprising high-frequency promoting vibrations. Along another vibrational coordinate, the system becomes impulsively out of equilibrium as a result of the electron transfer reaction. This leads to the generation (by the electron transfer reaction, not the laser pulse) of a new vibrational coherence along this second reaction coordinate in a mode associated with the reaction product. These results resolve a complex reaction trajectory composed of multiple vibrational coordinates that, like a sequence of ratchets, progressively diminish the recurrence of the reactant state.

DOI: 10.1038/s41557-020-00607-9

Source: https://www.nature.com/articles/s41557-020-00607-9