- Paired electrosynthesis at the femtoliter scale: Formation of 9,10-anthracenedione from the oxidation of anthracene and reduction of dioxygen
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A system is described in which the unique properties of a pair of microband electrodes are exploited both to initiate and to probe the products of a paired electrosynthesis using short-lived species. In particular, the oxidation of anthracene is coupled with the simultaneous reduction of dioxygen in acetonitrile to yield the anthracene radical cation and the superoxide anion. These latter react within a femtoliter scale volume to form initially 9,10-dihydro-9,10-epidioxyanthracene, which rearranges into 9,10-anthracenedione and, presumably, dihydrogen via an electron transfer catalyzed process.
- Amatore, Christian,Brown, Alan R.
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- Photochemical reaction of anthracene with dioxygen catalyzed by platinum(II) porphyrin
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Visible light irradiation of anthracene in the presence of platinum(II) porphyrin (PtPor) and dioxygen affords anthraquinone as the main product. This reaction involves two steps: the [4+2]cycloaddition of anthracene with singlet oxygen to afford anthracene-9,10-endoperoxide and the degradation of endoperoxide. PtPor catalyzes both reactions.
- Yamashita, Ken-ichi,Sugiura, Ken-ichi
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- Photochemistry of anthracene in water
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Photolysis of anthracene (350 nm) in aerated water yields endoperoxide and 9,10-anthraquinone as the major primary photoproducts. Photolysis of anthracene in oxygen-deficient aqueous solutions yields the three isomers of 10,10'-dihydroxy-9,9',10,10'-tetrahydro-9,9'-bianthryl as the primary photoproduct. Involvement of a cation radical mechanism is suggested.
- Sigman,Zingg,Pagni,Burns
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- Substrate-Selectivity in Catalytic Photooxygenation Processes Using a Quinine-BODIPY System
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Substrate selectivity by means of synthetic catalysts remains a challenging topic in chemistry. Here, a catalytic system combining an iodo-BODIPY photosensitizer and quinine was evaluated in the competitive photooxygenation of non-hydrogen and hydrogen-bond-donor substrates. The ability of quinine to activate hydrogen-bond-donor substrates towards photooxygenation was reported and the results were benchmarked with photooxygenation experiments in the absence of quinine.
- Coeffard, Vincent,Fischer, Jér?me,Nun, Pierrick,Serier-Brault, Hélène
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supporting information
p. 463 - 468
(2020/03/13)
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- Meso-disubstituted anthracenes with fluorine-containing groups: Synthesis, light-emitting characteristics, and photostability
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(Chemical Equation Presented) Synthesis, photophysical properties, and photostability of 9,10-disubstituted anthracenes with fluorine-containing groups (FCG) are described. The values of Φf and λem greatly go up by the meso-substitution with FCG, and a nice corelationship between Φf and Aπ (magnitude of π conjugation length in the excited single state) is observed. The C6F5 group at the meso positions exhibits an excellent ability in the photostability as well as in the emission efficiency.
- Matsubara, Yoshio,Kimura, Atsushi,Yamaguchi, Yoshihiro,Yoshida, Zen-ichi
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supporting information; experimental part
p. 5541 - 5544
(2009/05/30)
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- Photocatalytic oxygenation of anthracenes and olefins with dioxygen via selective radical coupling using 9-mesityl-10-methylacridinium ion as an effective electron-transfer photocatalyst
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Visible light irradiation of the absorption band of 9-mesityl-10- methylacridinium ion (Acr+-Mes) in an O2-saturated acetonitrile (MeCN) solution containing 9,10-dimethylanthracene results in formation of oxygenation product, i.e., dimethylepidioxyanthracene (Me 2An-O2). Anthracene and 9-methylanthracene also undergo photocatalytic oxygenation with Acr+-Mes to afford the corresponding epidioxyanthracenes under the photoirradiation. In the case of anthracene, the further photoirradiation results in formation of anthraquinone as the final six-electron oxidation product, via 10-hydroxyanthrone, accompanied by generation of H2O2. When anthracene is replaced by olefins (tetraphenylethylene and tetramethylethylene), the photocatalytic oxygenation of olefins affords the corresponding dioxetane, in which the O-O bond is cleaved to yield the corresponding ketones. The photocatalytic oxygenation of anthracenes and olefins is initiated by photoexcitation of Acr+-Mes, which results in formation of the electron-transfer state: Acr?- Mes?+, followed by electron transfer from anthracenes and olefins to the Mes?+ moiety together with electron transfer from the Acr? moiety to O2. The resulting anthracene and olefin radical cations undergo the radical coupling reactions with O 2?- to produce the epidioxyanthracene (An-O 2) and dioxetane, respectively.
- Kotani, Hiroaki,Ohkubo, Kei,Fukuzumi, Shunichi
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p. 15999 - 16006
(2007/10/03)
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