Organic dyes are a family of compounds of significant industrial interest for both material and biological applications. In this field, the most recent efforts have been focused on emission (absorption and emission). The most sought dyes are those which absorb in the infrared, which have a large quantum yield, a great (photo) stability, etc. In this context, the group has the technology to model both the absorption and emission of these molecules considering the vibronic coupling and solvent effects using refined models developed in-house. The methodology used allows the experimental data to be reproduced and explained. It is therefore possible to predict variations in optical spectra (shapes and positions) during auxochromic substitutions, variations in pH, effects of solvochromism and acidochromism ... and therefore to propose new effective dyes to experimenters.

Numerous varieties of dyes have been studied in this thematic; therefore, only recent subjects are highlighted here. This axis notably includes (i) the study of new fluorescent dyes based on pyrrolopyrroles and alike cores, (ii) understanding and characterizing the reactivity of the derivatives of original cyanine derivatives and (iii) simulating the properties of dyes exhibiting an excited state intramolecular proton transfer (ESIPT). Note that the test bench studies (choice of the functional in DFT, the basis of atomic functions, the solvent model, the method, etc.) making it possible to define a protocol in order to characterize the excited states (vibronic spectra and vertical transitions) are found in the cross-cutting theme about methodological developments.

Selected publications:

(i)    M. Tasior, P. Kowalczyk, M. Przybyl, M. Czichy, P. Janasik, M. H. E. Bousquet, M. Lapkowski,M. Rammo, A. Rebane, D. Jacquemin, D. T. Gryko Chem. Sci. 12 (2021), 15935-15946. Skonieczny, I.            Papadopoulos, D. Thiel, K. Gutkowski, P. Haines, http://doi.org/10.1039/D1SC05007AP. M. McCosker, A. D. Laurent, P. A. Keller, T. Clark, D. Jacquemin, D. M. Guldi, D. T. Gryko Angew. Chem. Int. Ed. 59 (2020) 16104-16113. G. Sanil, M. Krzeszewski, W. Danikiewicz, L. Dobrzycki, I. Knysh, L. Dobrzycki, M. K. Cyrabski, D. Jacquemin, D. T. Gryko Angew. Chem. Int. Ed. 62 (2023) e202311123.

(ii)   B.  Mourot, V. Mazan, M. Elhabiri, R. Sarkar, D. Jacquemin, O. Siri and S. Pascal, Chem. Sci. 15 (2024), 1248-1259. S. Pascal, A. Torres Ruiz, A. E. Baker, D. A. Vander Griend, M. Giorgi, A. Planchat, D. Jacquemin, O. Siri Angew. Chem. Int. Ed. 59 (2025) e202511037. F. Ceugniet, V. Ott, P. Retailleau, Y. Bretonniere, O. Maury, M. H. E. Bousquet, L. Sancey, N. Leclerc, D. Jacquemin and G. Ulrich, Angew. Chem. Int. Ed. 65 (2026) e26011.

(iii)  T. Stoerkler, G. Ulrich, P. Retailleau, A. D. Laurent, D. Jacquemin, J. Massue, Chem. Sci. 15 (2024) 7206-7218. T. Stoerkler, G. Ulrich, A. D. Laurent, D. Jacquemin, J. Massue, Org. Chem. Front. 12 (2025) 6111-6119.

This research axis involves the modeling of photobiological systems involving chromophore or photochrome using complementary approaches combining virtual screening, molecular docking, molecular mechanics, QM/MM hybrid methods and semi-empirical methods in order to characterize their conformational and spectral properties. The objectives of this axis are (i) to employ a multi-scaling computational protocols that are able to (i) explore the embedding effect going from a solvent to a complex environment (protein, cages,…), (ii) to determine or predict the binding site of a chromophore or a photochrome in a protein complex, and (ii) modulate the binding site to explore the conformational changes and the associated optical properties.

Selected publications:

(i)   M. Asad and Adèle D. Laurent Phys.Chem. Chem. Phys. 2022, 24, 3816-3825
(ii)  A. Demeyer, L. Fonteneau, M. Liennard, C. Foyer, P. Weigel, A. D. Laurent, J. Lebreton, F. Fleury, and M. Mathé-Allainmat Bioorg. Med. Chem. Lett. 2023, 87, 129261(1-6).

In order to understand photochemical reactions, experiments resolved in time with a temporal resolution of the order of a femtosecond (1 fs = 10^-15 s) played a major role in probing the movement of the nuclei in real time. Recent advances in attosecond science (1 as = 10^-18 s) open up the possibility of observing and controlling the movement of electrons on their intrinsic time scale. Because of the time-energy uncertainty principle, these extremely short duration pulses have a large spectral width. They can therefore be used to populate several excited electronic states in a coherent manner: this is called an electronic wave packet. Such a wave packet has a new electronic distribution (which is not the simple average of the electronic distributions of the different states). It can therefore be considered as a new type of initial electronic state.

This research axis aims to deepen the understanding of the dynamics induced by coherent electronic wavepackets and to study their application to photochemical reactions. This includes in particular (Figure-i) the theoretical exploration of the impact of electronic coherence on nuclear motion and (Figure-ii) experimental collaborations to obtain signatures of attochemistry.

Reference publications:

(i)    L. Fransén, S. Gómez and M. Vacher, J. Phys. Chem. Lett. 2025, 16, 8745-8751.
(ii)   A. Ferté, D. Austin, A. A. Johnson, F. McGrath, J. P . Malhado, J. P. Marangos and M. Vacher, Phys. Rev. Lett. 2024, 133, 203201.