Premium
PHOTOOXYGENATION OF BIPHENYL AND ITS DERIVATIVES via PHOTOINDUCED ELECTRON TRANSFER: EFFECT OF Mg(CIO 4 ) 2 ON PHOTOOXYGENATION
Author(s) -
Tamai Toshiyuki,
Mizuno Kazuhiko,
Hashida Isao,
Otsuji Yoshio
Publication year - 1991
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1991.tb01980.x
Subject(s) - photooxygenation , chemistry , benzoic acid , biphenyl , benzene , photochemistry , acetonitrile , medicinal chemistry , electron transfer , singlet state , naphthalene , organic chemistry , excited state , singlet oxygen , oxygen , physics , nuclear physics
The 9,10‐dicyanoanthracene (DCA)‐sensitized photooxygenation of biphenyl derivatives in the presence of Mg(CIO 4 ) 2 in acetonitrile produces benzoic acid and its derivatives in high yields. In the absence of Mg(CIO 4 ) 2 , the rates for the consumption of biphenyl derivatives decrease by a factor of 0.5‐0.8, compared with those in the presence of Mg(CIO 4 ) 2 . In these cases, however, both biphenyls and DCA are oxygenated to give benzoic acids and anthraquinone, respectively, indicating that the addition of Mg(CIO 4 ) 2 retards the photooxygenation of DCA. With 4‐methylbiphenyl, the photooxygenation proceeds efficiently without added Mg(CIO 4 ) 2 , and benzene rings and methyl groups are competitively oxygenated to give benzoic acid, 4‐methylbenzoic acid, 4‐phenylbenzoic acid, and 4‐phenylbenzaldehyde. The addition of Mg(CIO 4 ) 2 facilitates the oxidation of benzene rings, giving benzoic acid and 4‐methylbenzoic acid as major products. These photooxygenations are initiated by a one‐electron transfer from biphenyls to the excited singlet DCA and proceed via the radical cations of biphenyls and the radical anion of DCA.