Quenching of an Aniline Radical Cation by Dissolved Organic Matter and Phenols: A Laser Flash Photolysis Study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F20%3A00114580" target="_blank" >RIV/00216224:14310/20:00114580 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1021/acs.est.0c05230" target="_blank" >https://doi.org/10.1021/acs.est.0c05230</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.est.0c05230" target="_blank" >10.1021/acs.est.0c05230</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quenching of an Aniline Radical Cation by Dissolved Organic Matter and Phenols: A Laser Flash Photolysis Study

Popis výsledku v původním jazyce

Aromatic amines are relevant aquatic organic contaminants whose photochemical transformation is affected by dissolved organic matter (DOM). The goal of this study is to elucidate the underlying mechanism of the inhibitory effect of DOM on such reactions. The selected model aromatic amine, 4-(dimethylamino)benzonitrile (DMABN), was subjected to laser flash photolysis in the presence and absence of various model photosensitizers. The produced radical cation (DMABN(.+)) was observed to react with several phenols and different types of DOM on a time scale of similar to 100 mu s. The determined second-order rate constants for the quenching of DMABN(.+) by phenols were in the range of (1.4-26) X 10(8) M-1 s(-1) and increased with increasing electron donor character of the aromatic ring substituent. For DOM, quenching rate constants increased with the phenolic content of the DOM. These results indicate the reduction of DMABN(.+) to re-form its parent compound as the basic reaction governing the inhibitory effect. In addition, the photosensitized oxidation of the sulfonamide antibiotic sulfadiazine (SDZ) was studied. The observed radical intermediate of SDZ was quenched by 4-methoxyphenol less effectively than DMABN(.+), which was attributed to the lower reduction potential of the SDZ-derived radical compared to DMABN(.+).

Název v anglickém jazyce

Quenching of an Aniline Radical Cation by Dissolved Organic Matter and Phenols: A Laser Flash Photolysis Study

Popis výsledku anglicky

Aromatic amines are relevant aquatic organic contaminants whose photochemical transformation is affected by dissolved organic matter (DOM). The goal of this study is to elucidate the underlying mechanism of the inhibitory effect of DOM on such reactions. The selected model aromatic amine, 4-(dimethylamino)benzonitrile (DMABN), was subjected to laser flash photolysis in the presence and absence of various model photosensitizers. The produced radical cation (DMABN(.+)) was observed to react with several phenols and different types of DOM on a time scale of similar to 100 mu s. The determined second-order rate constants for the quenching of DMABN(.+) by phenols were in the range of (1.4-26) X 10(8) M-1 s(-1) and increased with increasing electron donor character of the aromatic ring substituent. For DOM, quenching rate constants increased with the phenolic content of the DOM. These results indicate the reduction of DMABN(.+) to re-form its parent compound as the basic reaction governing the inhibitory effect. In addition, the photosensitized oxidation of the sulfonamide antibiotic sulfadiazine (SDZ) was studied. The observed radical intermediate of SDZ was quenched by 4-methoxyphenol less effectively than DMABN(.+), which was attributed to the lower reduction potential of the SDZ-derived radical compared to DMABN(.+).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA19-08239S" target="_blank" >GA19-08239S: Spektroskopie a mikroskopie chemických látek v ledu pro environmentální a farmaceutické účely</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Environmental Science and Technology

ISSN

0013-936X

e-ISSN

1520-5851

Svazek periodika

54

Číslo periodika v rámci svazku

23

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

15057-15065

Kód UT WoS článku

000596728600032

EID výsledku v databázi Scopus

2-s2.0-85096560900