Laser flash photolysis study of the photoinduced oxidation of 4-(dimethylamino)benzonitrile (DMABN)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F19%3A00109353" target="_blank" >RIV/00216224:14310/19:00109353 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2019/PP/C8PP00519B#!divAbstract" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2019/PP/C8PP00519B#!divAbstract</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c8pp00519b" target="_blank" >10.1039/c8pp00519b</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Laser flash photolysis study of the photoinduced oxidation of 4-(dimethylamino)benzonitrile (DMABN)

Popis výsledku v původním jazyce

Aromatic amines are aquatic contaminants for which phototransformation in surface waters can be induced by excited triplet states of dissolved organic matter ((DOM)-D-3*). The first reaction step is assumed to consist of a one-electron oxidation process of the amine to produce its radical cation. In this paper, we present laser flash photolysis investigations aimed at characterizing the photoinduced, aqueous phase one-electron oxidation of 4-(dimethylamino) benzonitrile (DMABN) as a representative of this contaminant class. The production of the radical cation of DMABN (DMABN(center dot+)) after direct photoexcitation of DMABN at 266 nm was confirmed in accord with previous experimental results. Moreover, DMABN(center dot+) was shown to be produced from the reactions of several excited triplet photosensitizers (carbonyl compounds) with DMABN. Second-order rate constants for the quenching of the excited triplet states by DMABN were determined to fall in the range of 3 x 10(7)-5 x 10(9) M-1 s(-1), and their variation was interpreted in terms of electron transfer theory using a Rehm-Weller relationship. The decay kinetics of DMABN(-+) in the presence of oxygen was dominated by a second-order component attributed to its reaction with the superoxide radical anion (O-2(center dot-)). The first-order rate constant for the transformation of DMABN(center dot+) leading to photodegradation of DMABN was estimated not to exceed approximate to 5 x 10(3) s(-1).

Název v anglickém jazyce

Laser flash photolysis study of the photoinduced oxidation of 4-(dimethylamino)benzonitrile (DMABN)

Popis výsledku anglicky

Aromatic amines are aquatic contaminants for which phototransformation in surface waters can be induced by excited triplet states of dissolved organic matter ((DOM)-D-3*). The first reaction step is assumed to consist of a one-electron oxidation process of the amine to produce its radical cation. In this paper, we present laser flash photolysis investigations aimed at characterizing the photoinduced, aqueous phase one-electron oxidation of 4-(dimethylamino) benzonitrile (DMABN) as a representative of this contaminant class. The production of the radical cation of DMABN (DMABN(center dot+)) after direct photoexcitation of DMABN at 266 nm was confirmed in accord with previous experimental results. Moreover, DMABN(center dot+) was shown to be produced from the reactions of several excited triplet photosensitizers (carbonyl compounds) with DMABN. Second-order rate constants for the quenching of the excited triplet states by DMABN were determined to fall in the range of 3 x 10(7)-5 x 10(9) M-1 s(-1), and their variation was interpreted in terms of electron transfer theory using a Rehm-Weller relationship. The decay kinetics of DMABN(-+) in the presence of oxygen was dominated by a second-order component attributed to its reaction with the superoxide radical anion (O-2(center dot-)). The first-order rate constant for the transformation of DMABN(center dot+) leading to photodegradation of DMABN was estimated not to exceed approximate to 5 x 10(3) s(-1).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES

ISSN

1474-905X

e-ISSN

1474-9092

Svazek periodika

18

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

534-545

Kód UT WoS článku

000458569100026

EID výsledku v databázi Scopus

2-s2.0-85061394130