Quinoxaline ozonation in aqueous solution

Journal Article · · Ozone: Science and Engineering (The Journal of the International Ozone Association); (United States)

DOI:https://doi.org/10.1080/01919519008552200· OSTI ID:5641618

Andreozzi, R; Caprio, V; D'Amore, M G; Insola, A ^[1]

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1. Universita di Napoli (Italy)

The oxidation of quinoxaline by ozone in aqueous solution is investigated. The chemical and kinetic evolution of the oxidation process at varying pH are followed by means of semi-batch and batch ozonation experiments. Results indicate that quinoxaline ozonation can develop according to both radical and ionic mechanisms whose relative occurrence can be varied by means of addition to the reacting system of radical scavengers or ozone decomposition promoters. It is shown that each mechanism involves an initial attack of ozone to both the homocyclic and heterocyclic rings of quinoxaline. Pyrazinedicarboxylic acid is formed as a stable final product in ionic ozonation, whereas it appears as an intermediate still reactive towards ozone in radical ozonation. Despite this, the radical ozonation of quinoxaline appears to be more selective than ionic ozonation with respect to production of pyrazinedicarboxylic acid. Reaction schemes are proposed to account for the observed kinetic behaviors and product formations. Oxidation experiments have also been extended to pyrazine, and its sensitivity to only radical ozonation is shown.

• OSTI ID: 5641618
• Journal Information: Ozone: Science and Engineering (The Journal of the International Ozone Association); (United States), Journal Name: Ozone: Science and Engineering (The Journal of the International Ozone Association); (United States) Vol. 12:3; ISSN OZSED; ISSN 0191-9512
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AQUEOUS SOLUTIONS
AZINES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DISPERSIONS
HETEROCYCLIC COMPOUNDS
KINETICS
MIXTURES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
OZONIZATION
PH VALUE
PYRAZINES
REACTION KINETICS
SOLUTIONS