C-Photo: Computational photochemistry and in silico design of MOST systems

利用太阳能是满足现代社会能源需求的最有前途的途径。在这方面，一个基本上未被探索的概念是分子太阳能热（MOST）能量转换过程，它通过光化学触发的化学转化释放热量。在拟议的研究单位为MOST，这一概念是从基础研究的角度在合成，光谱，理论和应用的音乐会进行探讨。本建议涵盖了理论部分，重点是光化学和光谱方面。详细地说，遗传算法和机器学习方法将用于探索不同MOST系统的巨大化学空间，通过预先筛选最有前途的MOST分子，即所谓的mostophores。使用我们自主开发的激发态方法以及所有其他可用的理论工具进行进一步详细的量子化学研究补充了这些努力。然后将合成“最佳”候选物并进行光谱研究，重点关注最佳MOST特性，例如，高能量质量比，与太阳光谱的有利重叠以及与其他FOR MOST合作伙伴一起的适当存储时间。在这个项目中，我们将详细研究耦合偶氮苯，氮杂硼和降冰片二烯以及混合体系的储存状态的光化学转换机制。因此，我们将帮助设计新的mostophores通过先验的计算机设计，通过直接衍生化以及利用分子间的相互作用稳定的存储状态。该项目的另一个重要贡献是模拟分子环境中mostophores的光谱，以指导使用我们自主开发的量子化学方法和环境模型解释静态和时间分辨的实验光谱。沿着相同的路线，我们将研究氧化和/或还原开关的mostophores的可能性，即通过电子脱离和连接。开关机制将被计算和电子光谱的中间体将被模拟，以指导实验研究。因此，在这个项目中进行的理论工作很好地嵌入了FOR MOST研究单位，并将大大有助于合作项目。

The utilization of solar energy is the most promising pathway to cover the energy demands of our modern society. A largely unexplored concept is in this context the molecular solar thermal (MOST) energy conversion process, which releases heat through photochemically triggered chemical transformations on demand. In the proposed research unit FOR MOST, this concept is to be explored from a fundamental research point of view in concert of synthesis, spectroscopy, theory and application. This proposal covers the theoretical part with emphasis on the photochemical and spectroscopical aspects. In detail, genetic algorithms and machine learning approaches will be used to explore the vast chemical space of different MOST systems by pre-screening for the most promising MOST molecules, so-called mostophores. Further detailed quantum chemical investigations using our self-developed excited-state methods but also all other available theoretical tools complement the efforts. The “best” candidates will then be synthesized and spectroscopically investigated with focus on optimal MOST properties, for example, a high energy-to-mass ratio, favorable overlap with the solar spectrum and appropriate storage times together with the other FOR MOST partners. Within this project, we will investigate in detail the photochemical switching mechanisms into the storage state of coupled azobenzenes, azaborines and norbornadiene as well as of hybrid systems. We will thereby help to design novel mostophores by a priori in silico design, by straightforward derivatization as well as by exploitation of molecular interactions for the stabilization of the storage state. A further important contribution of this project is the simulation of optical spectra of the mostophores in their molecular environments to guide the interpretation of static and time-resolved experimental spectra using our self-developed quantum chemical methodology and environment models. Along the same lines, we will investigate the possibility of oxidative and/or reductive switching of the mostophores, i.e. by electron detachment and attachment. The switching mechanisms will be computed and electronic spectra of the intermediates will be simulated to guide experimental investigations. The theoretical efforts undertaken in this project are thus well embedded into the FOR MOST research unit and will contribute substantially the collaborative projects.