通过二维电子光谱研究溶剂依赖性的岩藻黄质特性揭示了分子内电荷转移态动力学的新细节。

Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy.

J Phys Chem Lett. 2021 May 27;12(20):4833-4840. doi: 10.1021/acs.jpclett.1c00851. Epub 2021 May 17.

The electronic state manifolds of carotenoids and their relaxation dynamics are the object of intense investigation because most of the subtle details regulating their photophysics are still unknown. In order to contribute to this quest, here, we present a solvent-dependent 2D Electronic Spectroscopy (2DES) characterization of fucoxanthin, a carbonyl carotenoid involved in the light-harvesting process of brown algae. The 2DES technique allows probing its ultrafast relaxation dynamics in the first 1000 fs after photoexcitation with a 10 fs time resolution. The obtained results help shed light on the dynamics of the first electronic state manifold and, in particular, on an intramolecular charge-transfer state (ICT), whose photophysical properties are particularly elusive given its (almost) dark nature.

类胡萝卜素的电子态和弛豫动力学是目前研究的热点，因为调控其光物理性质的许多细微细节仍然未知。为了对此进行研究，我们在本文中报告了一种依赖于溶剂的二向电子光谱（2DES）方法，用于对参与褐藻光捕获过程的羰基类胡萝卜素岩藻黄质进行表征。2DES 技术可以在 10fs 的时间分辨率下探测到光激发后 1000fs 内的超快弛豫动力学。所得结果有助于阐明第一电子态的动力学，特别是阐明分子内电荷转移态（ICT）的动力学，由于其（几乎）暗态性质，ICT 态的光物理性质特别难以捉摸。