Investigation of molecular rotation's influence on twisted ICT states in a series of D-A-A1 organic dyes

Investigation of molecular rotation's influence on twisted ICT states in a series of D-A-A1 organic dyes Full article

Journal

Dyes and Pigments
ISSN: 1873-3743 , E-ISSN: 0143-7208

Output data

Year: 2025, Volume: 239, Article number : 112761, Pages count : DOI: 10.1016/j.dyepig.2025.112761

Authors

Korshunov Vladislav M. ^1,2 , Chmovzh Timofey N. ^3,4 , Shlykov Ivan V. ⁵ , Minyaev Mikhail E. ⁴ , Taydakov Ilya V. ^6,2 , Rakitin Oleg A. ⁴

Affiliations

1	Bauman Moscow State Technical University, 5/1 2-ya Baumanskaya Str., 105005 Moscow, Russia
2	P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospect, 119991 Moscow, Russia
3	D. I. Mendeleev University of Chemistry and Technology of Russia, Miusskaya Sqr., 9, Moscow 125047, Russia
4	N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect, 47, Moscow, 119991, Russia
5	M.V. Lomonosov Moscow State University, Chemical Faculty, Leninsky Gory 1 Bldg.3, 119991, Moscow, Russia
6	G. V. Plekhanov Russian University of Economics, Stremyanny per. 36, 117997 Moscow, Russia

The Twisted Intramolecular Charge Transfer (TICT) phenomenon can, in some cases, lead to the formation of highly luminescent molecules. Such emitters require donor and acceptor units to be rotationally displaced in the ground state. However, the impact of molecular rotation in the excited state on the photophysical properties of compounds remains insufficiently understood. To bridge this gap, we synthesized and studied a series of donor-acceptor-acceptor (D-A-A1) organic dyes incorporating various chalcogenadiazole acceptors (A) and a cyanoacrylic acid acceptor (A1). Using spectroscopic analysis and TD-DFT calculations, we examined changes in electronic and geometric structures induced by subtle modifications in the acceptor units. Our findings reveal that compounds featuring an additional nitrogen atom in the ortho-position adopt a planar geometry in the first excited singlet state, leading to a blue shift in the emission spectrum while maintaining a high luminescence quantum yield of up to 63 % in cyclohexane. The results demonstrate that a planar excited-state geometry enhances ICT emission efficiency compared to a twisted configuration. Additionally, we identified a distinct solvatochromic behavior in the studied dyes. These insights contribute to a deeper understanding of the TICT mechanism and provide a new strategy for designing highly luminescent organic dyes.

Korshunov V.M. , Chmovzh T.N. , Shlykov I.V. , Minyaev M.E. , Taydakov I.V. , Rakitin O.A.
Investigation of molecular rotation's influence on twisted ICT states in a series of D-A-A1 organic dyes
Dyes and Pigments. 2025. V.239. 112761 . DOI: 10.1016/j.dyepig.2025.112761 Scopus OpenAlex

Submitted:	Feb 24, 2025
Published online:	Mar 20, 2025

Scopus:	2-s2.0-105000308116
OpenAlex:	W4408475625

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