A-Nor: New Concepts for the Norbornadiene/Quadricyclane (NBD/QC) Interconversion

对于未来MOST体系的设计和优化，精确的化学微调以及对光化学异构化机理的全面了解是非常重要的。因此，合成新的降冰片二烯/四环烷(NBD/QC)衍生物，开发高效、史无前例的催化触发能量释放过程成为人们关注的焦点。基于NBD/QC相互转化耦合以及生色团-生色团杂化结构，我们的目标是优化分子结构和系统性质，以便接近大多数竞争应用，同时对潜在的光异构化和能量释放过程的基本机制产生新的见解。为此，我们的提案将包括三个工作方案。工作包1的主旨是生成一个新的NBD/QC对及其相关杂环类似物的库，这些杂环类似物在桥中含有例如氧或氮。因此，重点是对NBD/QC对进行量身定制的功能化，以获得优化的光物理性质，这是未来应用所必需的。工作包2的任务是合成新型的亚甲基降冰片二烯杂化结构作为完全光开关体系的模型化合物。这将有助于揭示基本的开关过程，并对潜在的光物理机制产生全面的理解，从而允许精确的化学调节NBD/QC对的相关性质。在工作包3中，将研究从NBD到QC的[2+2]光环化反应和双层膜中逐壳功能化纳米粒子及其受限空间内的催化后向转化。因此，定制的功能化纳米颗粒将被用作a)准均相催化剂，b)提供可调节的受限空间反应场景的平台，以及c)允许例如在水溶液中操作的相转移介体。通过认真处理拟议的工作包，将调查三个主要研究问题：(I)如何设计和优化NBD/QC对，使其适合大多数低合成工作量和高效反应程序的系统？(2)我们如何实施基本的机械理解，以解开限制最相关属性的关键因素，如储能密度？(3)我们如何最大限度地提高由量身定制的纳米颗粒催化剂触发的催化能量释放的效率，将这种系统用于实际应用的主要挑战是什么？作为MOST的重要组成部分，我们的项目将通过提供一系列基于降冰片二烯的新型储能系统、用于基本机理研究的模型化合物和基于纳米粒子的催化剂来触发能量释放反应，从而推动未来的MOST技术。

For the design and optimization of future MOST systems, precise chemical fine-tuning as well as comprehensive understanding of the photochemical isomerization mechanism is of major importance. Therefore, the syntheses of new norbornadiene/quadricyclane (NBD/QC) derivatives and the development of efficient and unprecedented catalytically triggered energy release processes is targeted. Based on the NBD/QC interconversion couple, as well as chromophore-mostophore hybrid structures, our goal is to optimize the molecular architectures and system properties in order to approach competitive MOST applications while simultaneously generating new insights into the fundamental mechanistics of the underlying photoisomerization and energy release processes. For this purpose, our proposal will consist of three work-packages. The thrust of work-package 1 is to generate a library of new NBD/QC couples and their related heterocyclic analogues containing e.g. oxygen or nitrogen in the bridge. Consequently, the focus is to perform tailored functionalization of NBD/QC couples to obtain optimized photophysical properties, which are necessary for future applications. The synthesis of novel rylene-norbornadiene hybride structures as model compounds for fully photo-switchable systems is the task of work package 2. This will help to unravel the fundamental switching process and generate comprehensive understanding of the underlying photophysical mechanism, thus allowing for precise chemical tuning of the related properties of NBD/QC couples. In work-package 3, both the [2+2] photocyclization from NBD to QC and the catalytic back-conversion within shell-by-shell functionalized nanoparticles and their confined space in the bilayer, will be investigated. Therefore, tailor-made functionalized nanoparticles will be used as a) quasi-homogeneous catalysts, b) platforms providing a tunable confined space reaction scenario and c) as phase-transfer mediators allowing for example to operate in aqueous solutions. Through the conscientious processing of the proposed work-packages, three main research questions will be investigated: (i) How can we design and optimize NBD/QC couples as suitable MOST systems with low synthetic effort and efficient reaction procedures? (ii) How do we implement the fundamental mechanistic understanding to unravel the key factors limiting the relevant MOST properties such as energy storage density? (iii) How can we maximize the efficiency of the catalytic energy release trigged by tailor-made nanoparticle-based catalysts and what are the main challenges by using such systems for practical applications? As essential part within FOR MOST, our project will push forward the future MOST technology by providing a series of novel norbornadiene-based energy storage systems, model compounds for the investigation of fundamental mechanistics and nanoparticle-based catalysts to trigger the energy release reaction.