title: Aromatic Monochlorination Photosensitized by DDQ with Hydrogen Chloride under Visible-Light Irradiation.
abstract: Photochlorination of aromatic substrates by hydrogen chloride with 2,3-dichloro-5,6-cyano-p-benzoquinone (DDQ) occurs efficiently to produce the corresponding monochlorinated products selectively under visible-light irradiation. The yields for the chlorination of phenol were 70 % and 18 % for p- and o-chlorophenol, respectively, without formation of further chlorinated products. The photoinduced chlorination is initiated by electron transfer from Cl(-) to the triplet excited state of DDQ. The radical intermediates involved in the photochemical reaction have been detected by time-resolved transient absorption measurements.
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University and ALCA and SENTAN, Japan Science and Technology Agency (JST), Suita, Osaka, 565-0871, Japan. ookubo@chem.eng.osaka-u.ac.jp.|Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 120-750, Korea. ookubo@chem.eng.osaka-u.ac.jp.|Faculty of Science and Technology, Meijo University, ALCA and SENTAN, Japan, Science and Technology Agency (JST), Nagoya, Aichi, 468-8502, Japan. ookubo@chem.eng.osaka-u.ac.jp.
authors.forename: Kei
authors.identifier: http://orcid.org/0000-0001-8328-9249
authors.initials: K
authors.lastname: Ohkubo
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University and ALCA and SENTAN, Japan Science and Technology Agency (JST), Suita, Osaka, 565-0871, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fujimoto
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 120-750, Korea. fukuzumi@chem.eng.osaka-u.ac.jp.|Faculty of Science and Technology, Meijo University, ALCA and SENTAN, Japan, Science and Technology Agency (JST), Nagoya, Aichi, 468-8502, Japan. fukuzumi@chem.eng.osaka-u.ac.jp.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Fukuzumi
keywords: chlorination; laser flash photolysis; photoinduced electron transfer; quinone; radical