Versatile Coordination of Azocarboxamides: Redox‐Triggered Change of the Chelating Binding Pocket in Ruthenium Complexes
| Autor: | Julia Beerhues, Janez Košmrlj, Martin Gazvoda, Johannes Klein, David Schweinfurth, Margarethe van der Meer, Goutam Kumar Lahiri, Biprajit Sarkar |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010405 organic chemistry
Ligand Organic Chemistry chemistry.chemical_element General Chemistry Nuclear magnetic resonance spectroscopy 010402 general chemistry 01 natural sciences Combinatorial chemistry Redox Catalysis 0104 chemical sciences Ruthenium law.invention Metal chemistry.chemical_compound chemistry law visual_art Amide visual_art.visual_art_medium Chelation Electron paramagnetic resonance |
| Zdroj: | Chemistry – A European Journal. 24:18020-18031 |
| ISSN: | 1521-3765 0947-6539 |
| Popis: | Azocarboxamides occupy a special place among azo ligands owing to their versatility for metal coordination. Herein ruthenium complexes with two different azocarboxamide ligands that differ in the presence (or not) of a coordinating pyridyl heterocycle are presented. By making full use of the O,N(amide), N(azo), and N(pyridyl) coordinating sites, the first diruthenium complex that is bridged by an azo ligand containing two different binding pockets was obtained. Moreover, it was conclusively proven that, in the mononuclear complexes, oxidation at the ruthenium center leads to a complete change of coordination at the chelating binding pocket. The complexes were characterized by NMR spectroscopy, mass spectrometry, and single-crystal X-ray diffraction. Additionally, the mechanism of the aforementioned redox-triggered change in the chelating binding pocket and the electronic structures of all the complexes were investigated by a combination of electrochemistry, UV/Vis/NIR/EPR spectroelectrochemistry, and DFT calculations. This is first instance in which a redox-driven change in the complete chelating binding pocket has been observed in a ruthenium complex as well as with azo-based ligands. These results thus show the potential of these versatile azocarboxamide ligands to act as redox-driven switches with possible relevance to electrocatalysis. |
| Databáze: | OpenAIRE |
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