title: Redox-active ligand-induced homolytic bond activation.
abstract: Coordination of the novel redox-active phosphine-appended aminophenol pincer ligand (PNO(H2) ) to Pd(II) generates a paramagnetic complex with a persistent ligand-centered radical. The complex undergoes fully reversible single-electron oxidation and reduction. Homolytic bond activation of diphenyldisulfide by the single-electron reduced species leads to a ligand-based mixed-valent dinuclear palladium complex with a single bridging thiolate ligand. Mechanistic investigations support an unprecedented intramolecular ligand-to-disulfide single-electron transfer process to induce homolytic SS cleavage, thereby releasing a thiyl (sulfanyl) radical. This could be a new strategy for small-molecule bond activation.
authors.affiliation: Homogeneous, Bioinspired & Supramolecular Catalysis van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (The Netherlands).
authors.forename: Daniël L J
authors.initials: DL
authors.lastname: Broere
authors.forename: Lotte L
authors.initials: LL
authors.lastname: Metz
authors.forename: Bas
authors.initials: B
authors.lastname: de Bruin
authors.forename: Joost N H
authors.initials: JN
authors.lastname: Reek
authors.forename: Maxime A
authors.initials: MA
authors.lastname: Siegler
authors.forename: Jarl Ivar
authors.initials: JI
authors.lastname: van der Vlugt
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004220:Disulfides / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D008024:Ligands; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D004220:Disulfides; D008024:Ligands; D010165:Palladium
keywords: bond activation; mixed valency; palladium; phosphane ligands; redox-active ligands