Characterization of Novel Polyhalogen Monoanions

本提案旨在提供各种实验光谱工具，并通过最先进的量子化学计算来指导新型多卤阴离子的制备，这些多卤阴离子具有挑战性，但对于在基质隔离条件下进行研究具有指导意义，并且有望建立非共价网络。关于所有这些非共价相互作用有许多重要的问题，例如它们有多强，主要贡献是什么，它们如何随构象变化，以及这些如何受到晶体堆积效应的影响等，最后，这些知识如何用于设计新的结构和应用。一个主要的目标是在基质分离条件下制备这种新的弱结合体系，该条件允许在非常低的温度（<20 K）下对有效分离的分子体系（伪气相条件）进行严格的时间无关的光谱表征。从足够简单但具有高度挑战性的系统，如[F5]-，[Cl 5]-，和类似的interhalide对应物，如[F（Cl 2）2]-，[Cl（Br 2）2]-，[F（Br 2）2]-获得的实验结果将发展我们对这些富电子系统中非共价相互作用的理解，并将用于验证最先进的量子化学计算。除了有效分离的分子物种的光谱学，我们还打算大量制备新的多卤基单阴离子，如[Cln]-; n= 5，7，9和新的卤间单阴离子如[F（Br 2）2]-或[Cl（Br 2）2]-。这个子项目将阐明从孤立的分子种类到溶液中的大量物质，以及固态中的扩展网络的转变。新物种的制备将由各种可用的光谱技术，如低温IR，UV/维斯和原位拉曼光谱，以及单晶X射线结构测定指导，其潜在的应用将结合高层次的量子化学研究进行探索。

The present proposal aims at providing a variety of experimental spectroscopic tools comple-mented by state-of-the-art quantumchemical calculations guiding the preparation of novel polyhalogen anions which are challenging but instructive to study undermatrixisolation conditions and which are expected to build up noncovalent networks. There is a number of important questions regarding all these non-covalent interactions, such as how strong they are and what are the main contributions, how these change with the conformation, and how these are affected by crystal packing effects etc, and finally, how can this knowledge be used to design novel structures and applications. A primary goal is the preparation of such novel weakly bound systems under matrixisolation conditions which allows a rigorous time independent spectroscopic characterization of effectively isolated molecular systems (pseudo-gas-phase conditions) at very low temperatures (<20 K). The experimental results obtained from sufficiently simple but highly challenging systems such as [F5]-, [Cl5]-, and analogous interhalide counterparts such as [F(Cl2)2]-, [Cl(Br2)2]-, [F(Br2)2]- will develop our understanding of noncovalent interaction in these electron-rich systems and will be used to validate state-of-the-art quantum chemical calculations. Beside spectroscopy on effectively isolated molecular species we intend to prepare novel polyhalogene monoanions also in bulk quantities, such as [Cln]-; n=5,7,9 and new interhalogen monoanions like [F(Br2)2]- or [Cl(Br2)2]-. This subproject will elucidate the transition from isolated molecular species to bulk quantities in solution, and to extended networks in the solid state. The preparation of novel species will be guided by a variety of available spectroscopic techniques such as low-temperature IR, UV/VIS, and in situ Raman spectroscopy, as well as single crystal x-ray structure determination, and their potential applications will be explored in combination with high-level quantum chemical studies.