The Effect of the N-Oxide Oxygen Atom on the Crystalline and Photophysical Properties of [1,2,5]Oxadiazolo[3,4-d]pyridazines

The Effect of the N-Oxide Oxygen Atom on the Crystalline and Photophysical Properties of [1,2,5]Oxadiazolo[3,4-d]pyridazines Full article

Journal

Molecules
ISSN: 1420-3049

Output data

Year: 2025, Volume: 30, Number: 11, Article number : 2374, Pages count : DOI: 10.3390/molecules30112374

Authors

Chmovzh Timofey N. ^1,2 , Tsorieva Alisia V. ³ , Korshunov Vladislav M. ³ , Kotov Egor D. ^1,2,4 , Nasyrova Darina I. ² , Minyaev Mikhail E. ² , Datskevich Nikolay P. ³ , Taydakov Ilya V. ³ , Elinson Michail N. ² , Rakitin Oleg A. ²

Affiliations

1	D. I. Mendeleev University of Chemistry and Technology of Russia, Miusskaya sqr., 9, 125047 Moscow, Russia
2	N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia
3	P. N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia
4	Skoltech Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia

A series of novel fluorescent donor–acceptor–donor (D-A-D) dyes containing [1,2,5]oxadiazolo[3,4-d]pyridazine and its 1-oxide as electron-withdrawing groups has been synthesized and thoroughly investigated using X-ray diffraction and molecular spectroscopy methods. This study showed that the introduction of N-oxide into the 1,2,5-oxadiazole ring in the acceptor fragment leads to a significant decrease in the luminescence intensity and quantum yield of the dyes. A comprehensive comparison of the photophysical properties of the obtained compounds containing the 1,2,5-oxadiazole ring with the previously studied [1,2,5]thia- and 1,2,5-selenadiazolo[3,4-d]pyridazine analogs showed that the oxygen substitution in the acceptor fragment shifts the phosphorescence maximum from the NIR region of 980–1100 nm to the red region of 690–770 nm. In contrast, for oxygen- and sulfur-containing dyes, purely red fluorescence with a maximum in the spectral range of 620–900 nm is observed. The crystal structures of furoxan-containing 3d·½CHCl3 and furazan-containing 4d exhibit a non-planar [1,2,5]oxadiazolo[3,4-d]pyridazine fragment. We have found that short non-covalent interactions of the furoxan system with a lattice chloroform molecule in 3d lead to luminescence quenching. Meanwhile, in the 4d dye, the intermolecular π-π interactions of pyridazine nitrogen atoms with the N-carbazolyl group of the adjacent molecule should facilitate intermolecular charge transfer (ICT) emission. Thus, the luminescence maxima for these dyes can be tuned across a broad range of 700–1100 nm by varying the number of chalcogen atoms, highlighting the potential for tailoring optical properties in optoelectronic applications.

Chmovzh T.N. , Tsorieva A.V. , Korshunov V.M. , Kotov E.D. , Nasyrova D.I. , Minyaev M.E. , Datskevich N.P. , Taydakov I.V. , Elinson M.N. , Rakitin O.A.
The Effect of the N-Oxide Oxygen Atom on the Crystalline and Photophysical Properties of [1,2,5]Oxadiazolo[3,4-d]pyridazines
Molecules. 2025. V.30. N11. 2374 . DOI: 10.3390/molecules30112374 WOS Scopus OpenAlex

Web of science:	WOS:001506034700001
Scopus:	2-s2.0-105007686409
OpenAlex:	W4410874940

DB	Citing
OpenAlex	Нет цитирований
Scopus	Нет цитирований