Investigation on the photoreactions of nitrate and nitrite ions with selected azaarenes in water

Abstract:

:The photoreactions of selected azaarenes with nitrate and nitrite ions were investigated under irradiation at lambda = 313 nm. The excitation of both anions leads to several photochemical reactions forming mainly hydroxyl radicals and nitrogen oxides. The purification capability of natural waters i.e. the oxidation of inorganic and organic substances results from the formation of hydroxyl radicals. Nitrated isomers of azaarenes were found among the main products of the investigated photoreactions. The nitrogen oxides were responsible for the production of nitrated derivatives which possess a high toxic potential. Their formation was explained by the parallel occurance of two mechanism, a molecular and a radical one. The molecular mechanism became more important with increasing ionisation potentials of the azaarenes. The spectrum of oxidized products corresponded to the one got in the photoreactions of azaarenes with hydrogen peroxide. The formation of several oxidation and nitration products of the pyridine ring with its low electron density was explained by the reaction of excited states of azaarenes. The photoreactions with nitrite ions only led to the formation of oxidized and nitrated products. Nitroso products were not formed. The reactivity of nitrogen monoxide is too low for its reaction with the azaarenes.

journal_name

Chemosphere

journal_title

Chemosphere

authors

Beitz T,Bechmann W,Mitzner R

doi

10.1016/s0045-6535(98)00188-x

subject

Has Abstract

pub_date

1999-01-01 00:00:00

pages

351-61

issue

2

eissn

0045-6535

issn

1879-1298

pii

S004565359800188X

journal_volume

38

pub_type

杂志文章