Homo‐ and heterobinuclear Cu and Pd complexes with a bridging redox‐active bisguanidino‐substituted dioxolene ligand

• Verfasst von: Schrempp, David [VerfasserIn]
• Verfasst von: Schneider, Elisa [VerfasserIn]
• Verfasst von: Kaifer, Elisabeth [VerfasserIn]
• Verfasst von: Wadepohl, Hubert [VerfasserIn]
• Verfasst von: Himmel, Hans-Jörg [VerfasserIn]
• Titel: Homo‐ and heterobinuclear Cu and Pd complexes with a bridging redox‐active bisguanidino‐substituted dioxolene ligand
• Titelzusatz: electronic structure and metal-ligand electron‐transfer
• Verf.angabe: David Fridolin Schrempp, Elisa Schneider, Elisabeth Kaifer, Hubert Wadepohl, and Hans-Jörg Himmel
• Umfang: 13 S.
• Fussnoten: Gesehen am 05.04.2018
• Titel Quelle: Enthalten in: Chemistry - a European journal
• Jahr Quelle: 2017
• Band/Heft Quelle: 23(2017), 48, S. 11636-11648
• ISSN Quelle: 1521-3765
• DOI: doi:10.1002/chem.201702053
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1571753672

Abstract

Abstract A new redox?active 4,5?bisguanidino?substituted o?benzoquinone ligand?L is synthesized, which allows rational access to heterobinuclear complexes through the sequential coordination of two metals. In the examples discussed in this work, mononuclear Cu and Pd complexes are prepared in a first coordination step, and these complexes are then used as precursors to homobinuclear [CuII?L0?CuII] and heterobinuclear [PdII?L0?CuII] complexes. In the heterobinuclear complex, the PdII is coordinated by the softer bisguanidine side of L and the CuII by the harder dioxolene side (in line with the HSAB concept). The heterobinuclear complex is in a temperature?dependent equilibrium with its dimer, with two unsymmetrical Cu?Cl?Cu bridges. The redox?chemistry of the [CuII?L?CuII] and [PdII?L?CuII] complexes is studied. One?electron oxidation of both complexes was found to be quasi?reversible in CV experiments, and chemical one?electron oxidation was achieved with NO+(SbF6?). In the case of the homobinuclear complex [L(CuCl2)2]+, intramolecular ligand?metal electron?transfer, triggered by coordination of a CH3CN solvent molecule, leads to a temperature?dependent equilibrium between the form [CuII?L0?CuIII] at low temperatures (with CH3CN coordinated to the CuIII atom) and [CuII?L?+?CuII] at higher temperatures (without CH3CN).