Modeling the photochemical transformation of nitrobenzene under conditions relevant to sunlit surface waters: Reaction pathways and formation of intermediates


Vione D., De Laurentiis E., berto S., MINERO C., Hatipoglu A. , CINAR Z.

CHEMOSPHERE, vol.145, pp.277-283, 2016 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 145
  • Publication Date: 2016
  • Doi Number: 10.1016/j.chemosphere.2015.11.039
  • Title of Journal : CHEMOSPHERE
  • Page Numbers: pp.277-283
  • Keywords: Nitrobenzene, Hydroxyl radical, Photo-oxidative degradation, DFT calculation, COSMO, LABORATORY MEASURES, TITANIUM-DIOXIDE, SOLAR LIGHT, DEGRADATION, OXIDATION, POLLUTANTS, MATTER, FATE

Abstract

Nitrobenzene (NB) would undergo photodegradation in sunlit surface waters, mainly by direct photolysis and triplet-sensitized oxidation, with a secondary role of the (OH)-O-center dot reaction. Its photochemical half-life time would range from a few days to a couple of months under fair-weather summertime irradiation, depending on water chemistry and depth, NB phototransformation gives phenol and the three nitro phenol isomers, in different yields depending on the considered pathway. The minor (OH)-O-center dot role in degradation would make NB unsuitable as (OH)-O-center dot probe in irradiated natural water samples, but the selectivity towards (OH)-O-center dot could be increased by monitoring the formation of phenol from NB+(OH)-O-center dot. The relevant reaction would proceed through ipso-addition of (OH)-O-center dot on the carbon atom bearing the nitro group, forming a pre-reactive complex that would evolve into a transition state (and then into a radical addition intermediate) with very low activation energy barrier. (C) 2015 Elsevier Ltd. All rights reserved.