Gold-2-Go

除了极少数不发达的例子外，可分离的单核金(II)络合物的制备是不发达的。单核金(II)配合物的光谱和化学性质基本上是未知的。因此，该项目的目标是真正的单核金(II)络合物。具有理想化的方形平面和T型配位构型的金(II)配合物将通过使用四齿大环配体或三齿空间要求的螯合配体来动力学稳定，这将使光谱、磁性和结构表征成为可能。“真正的”电子性质(金属对配体为中心的自由基)将被阐明。光谱确认的金(II)络合物将通过预期的一阶和二阶Jahn-Teller扭曲的结构分析来研究。首次系统地探讨了这类不发达的复杂化合物的反应性(二聚化、歧化、氧化还原反应、自由基与底物的反应)。具体地说，具有配位数三和四的金(II)络合物是目标。在前一种情况下，通过Au-Au sigma键进行的二聚反应将被XY平面上的四个配体给体原子所阻止，而在第二种情况下，则被自由配位的空间保护所阻止。大环和三齿配体的计算机辅助筛选将使用量子化学方法进行。我们将利用先进的量子化学技术，使用大的基组来验证实验上可获得的金(II)络合物的电子结构。该项目将为开发金(II)络合物在催化、氧化还原催化以及可能的光氧化还原催化方面的潜力奠定基础。

The preparation of isolable mononuclear gold(II) complexes is apart from very few examples poorly developed. Spectroscopic and chemical properties of mononuclear gold(II) complexes are essentially unknown. Consequently, this project targets true mononuclear gold(II) complexes. Gold(II) complexes with idealized square-planar and T-shaped coordination geometry will be kinetically stabilized by using tetradentate macrocyclic ligands or tridentate sterically demanding chelate ligands which shall enable spectroscopic, magnetic and structural characterization. The “true” electronic nature (metal vs. ligand centered radical) will be elucidated. Spectroscopically confirmed gold(II) complexes will be studied by structural analyses with respect to expected first and second order Jahn-Teller distortions. The reactivity (dimerization, disproportionation, redox reactions, radical reactions with substrates) of this underdeveloped complex class will be systematically probed for the first time. Specifically, gold(II) complexes with coordination numbers three and four are targeted. Dimerization via Au-Au sigma bonds will be blocked by four ligand donor atoms in the xy plane in the former case and by steric protection of the free coordination site in the second case. Computer-aided screening of macrocylic and tridentate ligands will be performed using quantum chemical methods. The electronic structure of experimentally accessible gold(II) complexes will be verified employing advanced quantum chemical techniques using large basis sets. The project will lay the foundation to exploit the potential of gold(II) complexes in catalysis, redox catalysis and possibly photoredox catalysis.