A 1-Hydroxy-1H-imidazole ESIPT Emitter Demonstrating anti-Kasha Fluorescence and Direct Excitation of a Tautomeric Form

A 1-Hydroxy-1H-imidazole ESIPT Emitter Demonstrating anti-Kasha Fluorescence and Direct Excitation of a Tautomeric Form Full article

Journal

ChemPlusChem
ISSN: 2192-6506

Output data

Year: 2021, Volume: 86, Number: 10, Pages: 1436-1441 Pages count : 6 DOI: 10.1002/cplu.202100370

Tags

computational chemistry; heterocycles; hydrogen bonds; photochemistry; tautomerism

Authors

Shekhovtsov Nikita A. ¹ , Nikolaenkova Elena B. ² , Berezin Alexey S. ¹ , Plyusnin Victor F. ³ , Vinogradova Katerina A. ¹ , Naumov Dmitry Yu. ¹ , Pervukhina Natalia V. ¹ , Tikhonov Alexsei Ya. ² , Bushuev Mark B. ¹

Affiliations

1	Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Akad. Lavrentiev Ave., Novosibirsk, 630090, Russian Federation
2	N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, 9, Akad. Lavrentiev Ave., Novosibirsk, 630090, Russian Federation
3	Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, 3, Institutskaya str., Novosibirsk, 630090, Russian Federation

The ability of 1-hydroxy-1H-imidazoles to exist in the form of two prototropic tautomers, the N-hydroxy and the N-oxide forms, can be utilized in the design of new types of ESIPT-fluorophores (ESIPT=excited state intramolecular proton transfer). Here we report the first example of 1-hydroxy-1H-imidazole-based ESIPT-fluorophores, 1-hydroxy-5-methyl-2,4-di(pyridin-2-yl)-1H-imidazole (HL), featuring a short intramolecular hydrogen bond O−H⋅⋅⋅N (O⋅⋅⋅N 2.56 Å) as a pre-requisite for ESIPT. The emission of HL originates from the anti-Kasha S2→S0 fluorescence in the N-oxide form as a result of a large S2–S1 energy gap slowing down the S2→S1 internal conversion. Due to an energy barrier between the N-hydroxy and N-oxide forms in the ground state, the HL molecules can be trapped and photoexcited in the N-oxide form leading to the Stokes shift of ca. 60 nm which is the smallest among known ESIPT-fluorophores. © 2021 Wiley-VCH GmbH

Shekhovtsov N.A. , Nikolaenkova E.B. , Berezin A.S. , Plyusnin V.F. , Vinogradova K.A. , Naumov D.Y. , Pervukhina N.V. , Tikhonov A.Y. , Bushuev M.B.
A 1-Hydroxy-1H-imidazole ESIPT Emitter Demonstrating anti-Kasha Fluorescence and Direct Excitation of a Tautomeric Form
ChemPlusChem. 2021. V.86. N10. P.1436-1441. DOI: 10.1002/cplu.202100370 WOS Scopus РИНЦ

Web of science	WOS:000711464800013
Scopus	2-s2.0-85118221307
Elibrary	47518646
OpenAlex	W3203303395