Untersuchung hochreaktiver Organonickel-Komplexe mit Bedeutung für Nickel-katalysierte C-C-Kupplungsreaktionen

前两个项目启动的基于镍催化剂的单电子转移诱导C-C偶联反应的机理研究将被延长/延长。新的单核和双核有机镍模型化合物将被合成，并对其光谱和电化学(包括光谱电化学)进行了深入的研究。其中一个重点将放在研究还原的镍物种[(N^N)Ni(R)]·产生[(N^N)Ni(R)2]和[(N^N)Ni]的假定歧化-跨金属反应，最终导致不必要的同位偶合。另一个重点将放在有机卤化物R‘X与还原物种[(N^N)Ni(R)]·(包括环金属[(N^N^R)Nix]和“不对称”[(N^N’)Ni(R)X]衍生物)的氧化加成反应上，得到正式的Ni(III)配合物[(N^N)Ni(R)(R‘)X]·。用光谱电化学(EPR和UV-VIS-NIR光谱)和量子化学计算相结合的方法研究了两种自由基络合物(形式为Ni(I)和Ni(III))中的自旋离域。

The mechanistical investigation on single electron transfer induced C-C coupling reaction based on nickel catalysts started in two previous project will be extended/ prolonged. New mono- and binuclear organonickel model complexes carrying bi- or tridentate diimine (diazene) ligands) will be synthesised and their spectroscopy and electrochemistry (including spectroelectrochemistry) thoroughly investigated. one focus will be put on the investigation of the supposed disproportionation-transmetallation reaction of the reduced nickel species [(N^N)Ni(R)]• yielding [(N^N)Ni(R)2] and [(N^N)Ni] which finally leads to unwanted homo coupling. The other focus will be put on the oxidative addition reaction of organohalides R’X with the reduced species [(N^N)Ni(R)]• (including cyclometallated [(N^N^R)NiX] and „unsymmetrical“ [(N^N’)Ni(R)X] derivatives) yielding formal Ni(III) complexes [(N^N)Ni(R)(R‘)X]•. The spin delocalisation in both types of radical complexes {formally Ni(I) and Ni(III)} between chelate ligands, organo coligands and the metal will be studied using a combination of spectroelectrochemistry (EPR- and UV-Vis-NIR spectroscopy) and quantum chemical calculations.