Four-membered heterocyclic Biradicaloids: Reagents for Bond Activation and Ligands for 3d Transition-metals

均相催化是现代化学的一个重要研究领域，具有广阔的应用前景.贵金属如钯、铂和铑的分子络合物主要用作催化剂。不幸的是，由于它们的丰度低，它们对供应波动敏感，并且贵金属及其络合物的成本通常非常高。此外，复杂的采矿过程也对环境产生影响。因此，人们一直有兴趣用较轻的同系物取代这些金属，或使用主族化合物作为催化剂，而不是拟议的项目涉及一类有前途的化合物，这两种方法，即四元杂环双自由基。这些化合物构成开壳单态物质的亚组，其通常显示出高反应性。Schulz和Grützmacher小组的初步工作包括活化二氢、氨和多重键系统。该项目的目的是进一步探索这类有趣的化合物。因此，最终目标是将所研究的反应性并入催化循环中。为了实现这一目标，将进一步研究已知系统的反应性，并且将合成基于硅和砷的新的biradicaloid系统。此外，杂环biradicaloid将被用作3d过渡金属的氧化还原活性夹心配体，以模拟催化反应中的贵金属行为。

Homogeneous catalysis is a main research area in modern chemistry due to its enourmos application potential. Molecular complexes of precious metals like palladium, platinum and rhodium are predominantly used as catalysts. Unfortunately, because of their low abundance, they are sensitive towards supply fluctuations and the cost of the precious metals and complexes thereof are usually very high. In addition, environmental implications are associated with their complex mining processes. Therefore, there is an ongoing interest to replace those metals by their lighter congeners or to use main-group compounds as catalysts instead.The proposed project deals with a promising class of compounds for both approaches, namely four-membered heterocyclic biradicaloids. These compounds constitute a subgroup of open-shell singlet species which usually show a high reactivity. Preliminary work by the groups of Schulz and Grützmacher include the activation of dihydrogen, ammonia and multiple-bond systems. The aim of this project is the further exploration of this intriguing class of compounds. Thereby, the ultimate goal is the incorporation of the studied reactivity into catalytic cycles. To achieve this goal, the reactivity of known systems is going to be studied further and also, new biradicaloid systems based on silicon and arsenic will be synthesised. Additionally, the heterocyclic biradicaloids will be utilised as redox-active sandwich ligands for 3d transition-metals in order to mimic precious-metal behaviour in catalytic reactions.