- Polar Radicals. 16. Comments on a Recently Published Mechanistic Study of Photobromination Using Bromotrichloromethane
-
The mechanism of the photobromination reactions of a series of 10-substituted 9-methylanthracenes with bromotrichloromethane was reexamined.It was shown, contrary to the previous report, that the reaction proceeded by a mixed chain involving abstraction by both the bromine atom and the trichloromethyl radical.The kinetic results obtained from these reactions were shown to be dominated by reversible hydrogen transfer of the radicals formed in the reaction with the small amounts of hydrogen bromide produced from bromine atom abstraction.When the reactions were carried out in the presence of a hydrogen bromide scavenger, either ethylene oxide or powdered potassium carbonate, the kinetc results of photobromination were found to be almost insensitive to the effects of the changes in substituents.The reactivities of fluorene relative to the 10-substituted 9-methylanthracenes were found to be anomalously high, as was previously reported; however, when the reactions were carried out in the presence of ethylene oxide, the relative reactivities were shown to be predictably almost the same as those obtained when tert-butoxy radicals were the abstracting species.
- Tanner, Dennis D.,Blackburn, Edward V.,Reed, Darwin W.,Setiloane, B.P.
-
-
Read Online
- Photobase generator
-
The object of the present invention is to provide a photobase generator capable of efficiently generating amines (tertiary amines and amidine) high in catalytic activity by sensing light with a wavelength of from 350 to 500 nm (especially, from 400 to 500 nm). The present invention is a photobase generator characterized in being represented by general formula (1) or (2). Y+ is a quaternary ammonio group of general formula (3) to (5), and X? is a counter anion selected from among a borate anion, a phenolate anion, and a carboxylate anion.
- -
-
Page/Page column 34-35
(2013/02/27)
-