title: Bis-semiquinone (bi-radical) formation by photoinduced proton coupled electron transfer in covalently linked catechol-quinone systems: Aviram's hemiquinones revisited.
abstract: The structure and reactivity of a covalently linked catechol-ortho-benzoquinone (hemiquinone) is studied by UV-Vis and IR absorption spectroscopy. Nanosecond transient absorption spectroscopy of the hemiquinone reveals the formation of bi-radical state consisting of two semiquinone units. It is a long-lived state resulting from proton coupled electron transfer (PCET).
authors.affiliation: Molecular Photonics Group, van't Hoff Institute for Molecular Sciences (HIMS), Faculty of Science, Universiteit van Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Nguyên
authors.initials: N
authors.lastname: Vân Anh
authors.forename: René M
authors.initials: RM
authors.lastname: Williams
mesh_terms: D016227:Benzoquinones / Q000737:chemistry*; D002384:Catalysis; D002396:Catechols / Q000737:chemistry*; D004579:Electron Transport; D006860:Hydrogen Bonding; D011522:Protons; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D016227:Benzoquinones; D002396:Catechols; D011522:Protons; C004532:quinone; C034221:catechol