Polypyridine Iridium(III) and Ruthenium(II) Complexes for Homogeneous and Graphene‐Supported Photoredox Catalysis. Issue 5 (9th February 2023)

• Record Type: Journal Article
• Authors: Jacques, Alexandre; Devaux, Alexandre; Rubay, Christophe; Pennetreau, Florence; Desmecht, Antonin; Robeyns, Koen; Hermans, Sophie; Elias, Benjamin
• Is Part Of: ChemCatChem. Volume 15:Issue 5(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-02-09
• Subjects: graphene -- iridium -- photocatalysis -- photochemistry -- supported catalysts; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.202201672
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: Iridium(III) and ruthenium(II) polypyridyl based photocatalysts have been prepared and their structure determined using 1 H NMR, HR‐MS and single crystal XRD. Their spectroscopic and electrochemical properties have been studied by UV‐vis absorption, emission spectroscopy and cyclic voltammetry. These complexes have been used as photoredox homogeneous catalysts in an intramolecular cyclization model reaction in which they show high activity. They have been covalently anchored on graphene oxide (GO) via an esterification reaction and non‐covalently fixed on reduced graphene oxide (rGO) via pyrene moieties. Heterogenized complexes exhibit good photocatalytic activities and, interestingly, the use of a pyrene‐derivatized Ir(III) terpyridine‐based complex highlights an unexpected "on/off" effect of the photocatalytic activity triggered by the presence or absence of rGO. Abstract : New polypyridyl Ir(III) and Ru(II) complexes have been synthesized and used as photoredox catalysts for the radical cyclisation of malonates. In particular, a complex possessing a pyrene‐bearing terpyridine ligand displays an "on/off" catalytic activity. In homogenous phase, the complex is completely inactive but, adsorbed on reduced graphene oxide, it smoothly catalyses the cyclization reaction.