Molecular mechanisms of energy storage and release in MOST systems

点击翻译按钮获取中文摘要

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.