Article in Angewandte Chemie International Edition (2025)

09 01 2026

A paper, authored by the PhD student Jakub Drapała together with Krzysztof Durka, Katarzyna N. Jarzembska and Radosław Kamiński, was published in the Angewandte Chemie International Edition journal (Wiley-VCH). The investigations published in the article entitled “Reliable determination of photoreaction kinetics and cyclization/cycloreversion quantum yields for dithienylethene switches” were conducted during the realization of the OPUS grant (National Science Centre) within consortium consisting of University of Warsaw (leader) and Warsaw University of Technology (partner). The published article was awarded the issue inside front cover.

Dithienylethenes (DTEs) are among the most distinguished optically-switching compounds, as they undergo rapid and reversible isomerization reactions between open and closed forms by altering ultraviolet or visible light irradiation. The optical properties of these systems can be fine-tuned through a rational molecular design. This approach has been exploited for constructing many complex functional materials of specific properties which are then modulated by the on/off behaviour of the DTE unit. Consequently, DTE photoswitches have been successfully applied in optoelectronics, logic devices, medicine/biology, chemo- and biosensors, and catalysis. Although it was proved that the DTE photoswitches can easily be incorporated into various complex materials, there are still a lot of limitations that need to be overcome to expand their functionality from a model laboratory environment to real-life applications. This should be accompanied by an in-depth understanding of the mechanism underpinning the observed photoswitching behaviour supported by accurate determination of parameters describing the process, i.e., photoreaction quantum yield, photocyclization conversion, or reaction half-life.

In the just published paper, we present a universal and flexible model fully describing photoreaction kinetics in DTE systems is presented. The proposed method enables reliable determination of photocyclization and photocycloreversion quantum yields at various conditions. It is applicable to a broad range of photoswitch concentrations and accounts for competitive reactions, such as annulation of the closed form. By employing both analytical and numerical solutions to the kinetic equations, we achieved consistent results: the numerical method ensures high accuracy in quantum yield determination, while the analytical method allows for the prediction of DTE photoreaction behaviour. The robustness of the model was validated across four distinct DTE photoswitches under varying concentrations, solvents, excitation wavelengths conditions, demonstrating its broad applicability and reliability.

The research was carried out as part of the National Science Centre project (OPUS 2019/33/B/ST4/03144; PI: Radosław Kamiński).

Bibliographic data and link to the article:

J. Drapała, K. Durka, K.N. Jarzembska, R. Kamiński, Angewandte Chemie International Edition 2025, 65, e202514591

https://doi.org/10.1002/anie.202514591