Mathematical description of pH-stat kinetic traces measured during photochemical quinone decomposition

作者:Kiss Virag; Lehoczki Gabor; Osz Katalin*
来源:Photochemical and Photobiological Sciences, 2017, 16(4): 519-526.
DOI:10.1039/c6pp00333h

摘要

Substituted 1,4-benzoquinone (QR) derivatives are photosensitive in aqueous solution and form hydroquinones (QR-H-2) and hydroxy-quinones (QR-OH), two weak acids in their photoreaction. For this reason, the kinetics of the photoreaction can be conveniently followed by the pH-stat titration technique. The mathematical description of the kinetic traces measured provides the two main parameters of the photoreaction: the differential quantum yield of the reaction (F) and the ratio of the two photo-products, i.e. the fraction of QR that is converted to QR-OH (a). These values are described in this paper for 2,5-dichloro-1,4-benzoquinone at different pH values, together with the detailed mathematical evaluation of the application limits of the pH-stat method for such reactions.

  • 出版日期2017-4-1