101544-53-0Relevant articles and documents
Photooxygenation od 1,ω-Bis(diarylethenyl)alkanes via Photoinduced Electron-Transfer: Formation of 1,4-Radical Cations and Its Trapping by Molecular Dioxygen
Mizuno, Kazuhiko,Tamai, Toshiyuki,Hashida, Isao,Otsuji, Yoshio,Kuriyama, Yasunao,Tokumaru, Katsumi
, p. 7329 - 7334 (1994)
The 9,10-dicyanoanthracene (DCA)-sensitized photooxygenation of 1,ω-bis(diarylethenyl)alkanes (Ar2C=CH(CH2)nCH=Ar2) was studied.The photooxygenation of the alkadienes in acetonitrile afforded bicyclic peroxides when Ar = 4-CH3OC6H4, n = 3 and 4.When Ar = 4-CH3OC6H4, n = 2, 5, 8 or Ar = C6H5, n = 3, the photooxygenation did not afford bicyclic peroxides, but gave diaryl ketones.Laser flash photolysis studies indicated that the photooxygenation is initiated by a one-electron transfer from the alkadienes to 1DCA* and proceeds via 1,4-radical cations that are generated by an intramolecular cyclization between an ethenyl moiety and a radical cation of another ethenyl moiety.
Photooxygenation of 1,ω-Bis(diarylethenyl)alkanes via Photoinduced Electron Transfer: Formation of Bicyclic Peroxides
Tamai, Toshiyuki,Mizuno, Kazuhiko,Hashida, Isao,Otsuji, Yoshio
, p. 2641 - 2644 (1993)
The 9,10-dicyanoanthracene (DCA)-sensitized photooxygenation of Ar2C=CH(CH2)nCH=CAr2 in acetonitrile was studied.When Ar = 4-CH3OC6H4, n = 3 and 4, bicyclic peroxides were obtained via 1,4 radical cations that are generated by intramolecular interaction between two ethenyl moieties of the alkadienes.
Enantioselective protonation of radical anion intermediates in photoallylation and photoreduction reactions of 3,3-diaryl-1,1-dicyano-2-methylprop-1-ene with allyltrimethylsilane
Maeda, Hajime,Iida, Masayuki,Ogawa, Daisuke,Mizuno, Kazuhiko
, (2019/08/01)
Photoreactions of acetonitrile solutions of 3,3-diaryl-1,1-dicyano-2-methylprop-1-enes (1a–c) with allyltrimethylsilane (2) in the presence of phenanthrene as a photoredox catalyst and acetic acid as a proton source formed photoallylation (3) and photored
Activation conditions play a key role in the activity of zeolite CaY: NMR and product studies of Bronsted acidity
Kao, Hsien-Ming,Grey, Clare P.,Pitchumani, Kasi,Lakshminarasimhan,Ramamurthy
, p. 5627 - 5638 (2007/10/03)
CaY, activated under different conditions, was characterized with 1H, 31P, and 1H/27A] double resonance MAS NMR. The 1H MAS NMR spectra of CaY, calcined in an oven at 500 °C, shows resonances from H2O (bound to Ca2+ and the zeolite framework), CaOH+, aluminum hydroxides, silanols, and Bronsted acid sites. No evidence for Lewis acidity is observed on adsorption of trimethylphosphine, and an estimate of ≈16 Bronsted acid sites per unit cell is obtained for this sample. CaY activated in an oven at higher temperatures contains less water, but all the other species are still present. In contrast, CaY activated by slow ramping of the temperature under vacuum to 500 or 600 °C shows a much lower concentration of Bronsted acid sites (1/unit cell). Again, no evidence for Lewis acidity was observed. These NMR results have been utilized to understand the very different product distributions that are observed for reactions of 1,1- and 1,2-diarylethylenes in zeolite CaY activated in an oven (in air) and under vacuum. Samples with high concentrations of Bronsted acid sites react stoichiometrically with these sites, yielding diarylalkanes. At low concentrations, the Bronsted acid sites can act catalytically resulting in isomerization reactions.