The phenoxy radical: UV spectrum and kinetics of gas-phase reactions with itself and with oxygen

Study on the mechanism of photo-degradation of p-nitrophenol exposed to 254nm UV light

“…6(c) is obtained with the forming of a long-living intermediate with a strong absorption ranged from 330 to 420 nm. The transient species could be assigned to the peroxide radical of p-NP from reaction of p-NP • with molecular oxygen, which has been reported in gas phase [20]. It is also briefly reported by Feitelson et al, etc, that oxygen could accelerate the degradation of p-NP in UV photolysis [21].…”

Phenols from pyrolysis and co-pyrolysis of tobacco biomass components

“…For instance, phenol affects liver enzymes, lungs, kidneys, and the cardiovascular system, while m-cresol attacks the nervous systems (Talhout et al, 2011). Phenoxy radicals produced from further degradation of phenol (Khachatryan et al, 2008), on the other hand can combine to form dibenzo-p-dioxin/dibenzofuran (DD/F) which is one of the most toxic environmental pollutants (Berho and Lesclaux, 1997;Wiater et al, 2000;Khachatryan et al, 2003;Evans and Dellinger, 2005). The p-hydroxyl phenoxy radical known in literature as neutral semi-quinone radical has been reported in cigarette smoke and shown to be highly active in generation of reactive oxygen species (ROS) in biological systems (Pryor et al, 1998;Dellinger et al, 2000).…”

UV absorption cross-sections of phenol and naphthalene at temperatures up to 500 °C

“…Comparison of available literature data (green -[12]; blue -[13]; orange squares -[11]) and data obtained in this paper (red) between 200 nm and 310 nm (a) and a close-up between 264 nm and 271 nm (b). (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this article.…”

“…The studies of Breho and Lesclaux [11] from 1997 covers almost the full range but only shows the absorption cross-sections in very coarse steps of 2-20 nm, while Trost et al [12] and Etzkorn et al [13] investigated only the characteristic bands between 240 and 290 nm. These papers used a setup of a UV lamp (either a deuterium lamp [11,12] or a xenon high pressure lamp [13]) with a bandpass for the lower UV ranges, a monochromator (e.g., Czerny-Turner spectrograph) and a detector (either a photomultiplier [11] or a photodiode array detector [12,13] Three datasets of absorption cross-sections at room temperature are available for naphthalene in the spectral range investigated in this study. All experiments were obtained by absorption measurements with a grating spectrometer in a gas cell of different length and light sources.…”