Molecules that can undergo reversible chemical transformations following the absorption of light, the so-called molecular photoswitches, have attracted increasing attention in technologies, such as solar energy storage. Here, the optical and thermochemical properties of the photoswitch are central to its applicability, and these properties are influenced significantly by solvation. We investigate the effects of solvation on two norbornadiene/quadricyclane photoswitches. Emphasis is put on the energy difference between the two isomers and the optical absorption as these are central to the application of the systems in solar energy storage. Using a combined classical molecular dynamics and quantum mechanical/molecular mechanical computational scheme, we showcase that the dynamic effects of solvation are important. In particular, it is found that standard implicit solvation models generally underestimate the energy difference between the two isomers and overestimate the strength of the absorption, while the explicit solvation spectra are also less red-shifted than those obtained using implicit solvation models. We also find that the absorption spectra of the two systems are strongly correlated with specific dihedral angles. Altogether, this highlights the importance of including the dynamic effects of solvation.

中文翻译：

---

溶剂化对降冰片二烯/四环烷体系的动力学影响

吸收光后可以发生可逆化学转变的分子，即所谓的分子光开关，在太阳能存储等技术中引起了越来越多的关注。在这里，光电开关的光学和热化学性质是其适用性的核心，并且这些性质受到溶剂化的显着影响。我们研究了溶剂化对两个降冰片二烯/四环烷光电开关的影响。重点放在两种异构体之间的能量差和光学吸收上，因为这些是系统在太阳能存储中应用的核心。使用结合的经典分子动力学和量子力学/分子力学计算方案，我们证明了溶剂化的动态效应是重要的。特别是，我们发现标准隐式溶剂化模型通常会低估两种异构体之间的能量差并高估吸收强度，而显式溶剂化光谱也比使用隐式溶剂化模型获得的光谱红移较小。我们还发现两个系统的吸收光谱与特定的二面角密切相关。总而言之，这凸显了包括溶剂化动态效应的重要性。