Реферат: Chromones represent a class of molecular switches that convert into fluorescent products upon UV irradiation. To investigate their switching properties, we synthesized new 2‑furyl‑3‑acylchromones bearing different paramagnetic groups—2‑imidazoline‑3‑oxide‑1‑oxyl, 2‑imidazoline‑1‑oxyl, or piperidine‑N‑oxyl—in the acyl moiety of the molecules. The structures of the paramagnetic derivatives were determined by x‑ray diffraction. This analysis revealed that the benzoyl moiety adopts a conformation nearly perpendicular to the chromone plane. None of the studied spin‑labeled chromone derivatives exhibited luminescence in their native state. However, upon UV irradiation, they underwent a transformation accompanied by the appearance of a luminescence band with a maximum in the 491–514 nm range. Theoretical studies showed that the weak long‑wavelength bands in the electronic spectra of the spin‑labeled chromones correspond to combinations of α‑electron transitions: SOMO→LUMO and HOMO→SUMO. In contrast, the most intense band primarily arises from HOMO→LUMO electron transfers within the chromone moiety. This excitation leads to a transfer of electron density from the furan ring to the chromone moiety, facilitating a nucleophilic attack of the carbonyl oxygen on the furan C atom. Subsequent rearrangement yields furo[3,4‑b]chromones. Notably, this process is quenched by paramagnetic substituents located in the furan ring, but not by those in the acyl moiety.

Библиографическая ссылка: Agliulin K.V. , Stepanov A.V. , Nasyrova D.I. , Ilyushenkova V.V. , Yarovenko V.N. , Krayushkin M.M. , Ayt A.O. , Tretyakov E.V.
Chromones Functionalized With Nitroxide Radicals: Synthesis, Structural Characterization, and Photoinduced Luminescence Switching
Asian Journal of Organic Chemistry. 2026. V.15. N6. e70454 . DOI: 10.1002/ajoc.70454 WOS Scopus OpenAlex

Даты:

Поступила в редакцию:	15 февр. 2026 г.
Опубликована online:	30 мая 2026 г.

Идентификаторы БД:

≡ Web of science:	WOS:001779272500001
≡ Scopus:	2-s2.0-105040506456
≡ OpenAlex:	W7162857182

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