TY - JOUR

T1 - Primary photoprocesses for Fe(III) complexes with citric and glycolic acids in aqueous solutions

AU - Pozdnyakov, Ivan P.

AU - Tyutereva, Yuliya E.

AU - Mikheilis, Alexander V.

AU - Grivin, Vyacheslav P.

AU - Plyusnin, Victor F.

N1 - Funding Information: The financial support of the Russian Science Foundation (Grant RSF-NSFC № 21-43-00004 ) is gratefully acknowledged. Publisher Copyright: © 2022 Elsevier B.V.

PY - 2023/1/1

Y1 - 2023/1/1

N2 - The mechanism of UV photolysis of Fe(III) complexes with citric ([FeCit] and [Fe(OH)Cit]−) and glycolic ([FeGlyc]+) acids was revealed. The excitation of the complexes leads to the predominant formation of corresponding long-lived radical complexes exhibiting a low-intensity absorption band in the visible region (λmax = 600, 550 and 660 nm for ([FeCit], [Fe(OH)Cit]− and [FeGlyc]+ complexes, accordingly). The primary quantum yields of photolysis at 355 nm are 0.17, 0.28 and 0.12 for these complexes, accordingly. The decomposition of radical complexes leads to the appearance of corresponding organic radicals in solution, which are further oxidized in competitive processes by the initial complexes and dissolved oxygen. This enhances quantum yields of generation of ferrous ions in steady-state conditions and can also lead to a good yield of hydroxyl radicals in subsequent Fenton-like reactions in the presence of dissolved oxygen. The further study of the efficiency of [rad]OH radical generation upon excitation of these systems are urgently needed in order to estimate their role in environmental aqueous chemistry and to assess their potential use in advanced oxidation processes.

AB - The mechanism of UV photolysis of Fe(III) complexes with citric ([FeCit] and [Fe(OH)Cit]−) and glycolic ([FeGlyc]+) acids was revealed. The excitation of the complexes leads to the predominant formation of corresponding long-lived radical complexes exhibiting a low-intensity absorption band in the visible region (λmax = 600, 550 and 660 nm for ([FeCit], [Fe(OH)Cit]− and [FeGlyc]+ complexes, accordingly). The primary quantum yields of photolysis at 355 nm are 0.17, 0.28 and 0.12 for these complexes, accordingly. The decomposition of radical complexes leads to the appearance of corresponding organic radicals in solution, which are further oxidized in competitive processes by the initial complexes and dissolved oxygen. This enhances quantum yields of generation of ferrous ions in steady-state conditions and can also lead to a good yield of hydroxyl radicals in subsequent Fenton-like reactions in the presence of dissolved oxygen. The further study of the efficiency of [rad]OH radical generation upon excitation of these systems are urgently needed in order to estimate their role in environmental aqueous chemistry and to assess their potential use in advanced oxidation processes.

UR - http://www.scopus.com/inward/record.url?scp=85138029089&partnerID=8YFLogxK

U2 - 10.1016/j.jphotochem.2022.114274

DO - 10.1016/j.jphotochem.2022.114274

M3 - Article

AN - SCOPUS:85138029089

VL - 434

JO - Journal of Photochemistry and Photobiology A: Chemistry

JF - Journal of Photochemistry and Photobiology A: Chemistry

SN - 1010-6030

M1 - 114274

ER -