Molecular mechanisms of energy storage and release in MOST systems

在化石燃料资源日益减少的时代，对高效的能源生产和储存的需求越来越大。分子太阳能热能转换系统已成为太阳能储存的极具吸引力的替代方案。这种转换通常发生在超快的时间尺度上。因此，超快激光光谱学非常适合于实时分析这些光诱导过程。在这个项目中，最先进的时间分辨光谱技术将被用来研究新的、合理设计的降冰片二烯(NBD)、氮博林(BN)和偶氮苯(AB)基团的初级光化学。我们的研究将从分子水平上了解这些分子的初级光化学转化反应，以及不同取代基对储能效率的影响。我们还将开发优化热能释放(WP1)的照明协议。混合大多数系统提供了增加存储能量密度和扩大采光光谱范围的潜力。基于前人对多发色化合物的研究，我们将研究连接性模式对单个发色团单元的可寻址能力和功能性、分子间和分子内相互作用以及热稳定性(WP2)的影响。我们还将针对基于共价和非共价相互作用的多聚体的AB化合物的动力学。稳定系统可以通过ππ堆积或有吸引力的伦敦色散力来实现，它们的目标是同时增加存储能量密度和稳定热能存储状态(WP3)。在实际应用中，大多数化合物都要求在高密度环境中工作，分子间相互作用往往会影响其光化学性质。在大多数薄膜和限定表面上进行的超快光谱实验，以及与WP1溶液实验结果的比较，将指导联盟努力优化技术设备的一般性能(WP4)。在MOST内部，与合成基团的密切合作将支持新的MOST化合物的设计和优化。与理论小组一起，我们将在很大程度上有助于详细理解交换和存储过程的机械方面。

In times of diminishing fossil fuel resources, there is an increasing need for efficient energy generation and storage. Molecular solar thermal (MOST) energy conversion systems have become attractive alternatives to storing solar energy. This conversion typically occurs on an ultrafast time scale. Therefore, ultrafast laser spectroscopy is ideally suited to analyze these photoinduced processes in real time. Within this project, state-of-the-art time-resolved optical spectroscopic techniques will be employed to study the primary photochemistry of novel, rationally designed norbornadiene (NBD), azaborine (BN) and azobenzene (AB) based mostophores. Our studies will provide molecular understanding of the primary photochemical conversion reactions of these mostophores and the role of different substituents on thermal energy storage efficiency. We will also develop illumination protocols for optimized thermal energy release (WP1). Hybrid MOST systems offer the potential of an increased storage energy density and an expanded spectral range for light harvesting. Based on previous studies of multi-chromophoric compounds we will investigate the influence of connectivity patterns on the addressability and functionality of the individual chromophore units, inter- and intramolecular interactions and thermal stability (WP2). We will also target the dynamics of AB compounds based on covalently and non covalently interacting multimers. Stabilized systems can be achieved by e.g. π π stacking or by attractive London dispersion forces, they aim at simultaneously increasing the storage energy density and stabilizing the thermal energy storage state (WP3). For practical applications it is required that MOST compounds operate in high-density environment, where intermolecular interactions often affect the photochemical properties. Ultrafast spectroscopic experiments on MOST films and on defined surfaces and comparison to the results of the solution experiments from WP1 will guide the consortium efforts towards optimizing the general performance of technological devices (WP4). Within FOR MOST the close collaboration with the synthetic groups will support the design and optimization of new MOST compounds. Together with the theory groups we will substantially contribute to a detailed understanding of mechanistic aspects of switching and storage processes.