title: Disproportionation of a 2,2-diphenyl-1-picrylhydrazyl radical as a model of reactive oxygen species catalysed by Lewis and/or Brønsted acids.
abstract: Electron-transfer disproportionation of a 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) occurred in the presence of Sc(3+) acting as a strong Lewis acid in deaerated acetonitrile. In contrast, in the case of weaker Lewis acids than Sc(3+), such as Mg(2+) and Li(+), external protons from acetic acid were required for the disproportionation of DPPH˙ to occur.
authors.affiliation: Research Center for Charged Particle Therapy, National Institute of Radiological Sciences (NIRS), Inage-ku, Chiba 263-8555, Japan. nakanis@nirs.go.jp.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Nakanishi
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kawashima
authors.forename: Kei
authors.initials: K
authors.lastname: Ohkubo
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Waki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Uto
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kamada
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ozawa
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Shunichi
authors.initials: S
authors.lastname: Fukuzumi
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry*; D002384:Catalysis; D058116:Lewis Acids / Q000737:chemistry; D017616:Magnesium Compounds / Q000737:chemistry; D008698:Mesylates / Q000737:chemistry*; D010472:Perchlorates / Q000737:chemistry; D010851:Picrates / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000737:chemistry*; D012538:Scandium / Q000737:chemistry*
chemical_list: D000097:Acetonitriles; D001713:Biphenyl Compounds; D058116:Lewis Acids; D017616:Magnesium Compounds; D008698:Mesylates; D010472:Perchlorates; D010851:Picrates; D017382:Reactive Oxygen Species; C436603:scandium triflate; C016547:magnesium perchlorate; C004931:1,1-diphenyl-2-picrylhydrazyl; D019342:Acetic Acid; D012538:Scandium; C032159:acetonitrile