2022
The complex photochemistry of coumarin-3-carboxylic acid in acetonitrile and methanol
YANG, Qiuyun, Jiri VANA a Petr KLÁNZákladní údaje
Originální název
The complex photochemistry of coumarin-3-carboxylic acid in acetonitrile and methanol
Autoři
YANG, Qiuyun (156 Čína, domácí), Jiri VANA a Petr KLÁN (203 Česká republika, garant, domácí)
Vydání
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES, CAMBRIDGE, ROYAL SOC CHEMISTRY, 2022, 1474-905X
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10403 Physical chemistry
Stát vydavatele
Velká Británie a Severní Irsko
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 3.100
Kód RIV
RIV/00216224:14310/22:00126427
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000796316200001
Klíčová slova anglicky
Photochemistry; Coumarin; Photooxidation; Singlet oxygen
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 15. 3. 2023 22:52, Mgr. Michaela Hylsová, Ph.D.
Anotace
V originále
Irradiation of coumarin-3-carboxylic acid in acetonitrile and methanol solutions at 355 nm results in complex multistep photochemical transformations, strongly dependent on the solvent properties and oxygen content. A number of reaction intermediates, which themselves undergo further (photo)chemical reactions, were identified by steady-state and transient absorption spectroscopy, mass spectrometry, and NMR and product analyses. The triplet excited compound in acetonitrile undergoes decarboxylation to give a 3-coumarinyl radical that traps molecular oxygen to form 3-hydroxycoumarin as the major but chemically reactive intermediate. This compound is oxygenated by singlet oxygen, produced by coumarin-3-carboxylic acid sensitization, followed by a pyrone ring-opening reaction to give an oxalic acid derivative. The subsequent steps lead to the production of salicylaldehyde, carbon monoxide, and carbon dioxide as the final products. When 3-coumarinyl radical is not trapped by oxygen in degassed acetonitrile, it abstracts hydrogen from the solvent and undergoes triplet-sensitized [2 + 2] cycloaddition. The reaction of 3-coumarinyl radical with oxygen is largely suppressed in aerated methanol as a better H-atom donor, and coumarin is obtained as the primary product in good yields. Because coumarin derivatives are used in many photophysical and photochemical applications, this work provides detailed and sometimes surprising insights into their complex phototransformations.
Návaznosti
EF17_043/0009632, projekt VaV |
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GA21-01799S, projekt VaV |
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LM2018121, projekt VaV |
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857560, interní kód MU (Kód CEP: EF17_043/0009632) |
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