Barlow Kyle, Phelps Ryan, Eng Julien, Ingle Rebecca A, Khakhulin Dmitry, Biednov Mykola, Dutta Sharmistha Paul, Jiang Yifeng, Lima Frederico A, Tiwari Vandana, Milne Christopher, Katayama Tetsuo, Coletta Marco, Brechin Euan K, Penfold Thomas J, Johansson J Olof
EaStCHEM School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh, EH9 3FJ, U.K.
Chemistry, School of Natural and Environmental Sciences, Newcastle University, NE1 7RU, Newcastle upon Tyne, U.K.
J Phys Chem Lett. 2025 May 1;16(17):4148-4154. doi: 10.1021/acs.jpclett.5c00383. Epub 2025 Apr 17.
Achieving ultrafast photomagnetic switching of single-molecule magnets (SMMs) could lead to simultaneous fast and dense data storage devices. To facilitate this, a thorough understanding of the ultrafast dynamics emerging after ultrashort laser pulse excitation is essential. However, the complex nature of these materials means there is a lack of established experimental techniques that can probe the spin dynamics in SMMs. Herein, we perform femtosecond time-resolved Mn K-edge X-ray emission spectroscopy on a Mn(III)-based trinuclear SMM (Mn) and the model system Mn(acac). The spectral changes of Mn(acac) are consistent with switching between Jahn-Teller distorted structures expected after photoexcitation. A similar result is observed for Mn; however, the Kβ signal also reveals insight into the distribution of spin states populated within 100 fs. The importance of using probes across the electromagnetic spectrum to gain a thorough understanding of the dynamics of exchange-coupled complexes is highlighted.
实现单分子磁体（SMM）的超快光磁开关可能会带来同时具备快速和高密度特性的数据存储设备。为推动这一目标的实现，深入了解超短激光脉冲激发后出现的超快动力学至关重要。然而，这些材料的复杂性质意味着缺乏能够探测SMM中自旋动力学的成熟实验技术。在此，我们对基于Mn（III）的三核SMM（Mn）和模型体系Mn（acac）进行了飞秒时间分辨Mn K边X射线发射光谱研究。Mn（acac）的光谱变化与光激发后预期的 Jahn-Teller 畸变结构之间的切换一致。在Mn中也观察到了类似的结果；然而，Kβ信号还揭示了对100飞秒内填充的自旋态分布的洞察。强调了使用跨越电磁光谱的探针来全面理解交换耦合复合物动力学的重要性。
