0617042 - ÚOCHB 2026 RIV GB eng J - Článek v odborném periodiku
Demuth, J. - Bednarik, S. - Machan, R. - Mocak, I. - Malinsky, T. - El Dahabova, M. A. - Holčák, J. - Miletín, M. - Labuta, Jan - Nováková, V. - Zimčík, P.
J-dimers of phthalocyanine analogues: structural characterization and their use for determination of association constants between ligands and the central cation.
Inorganic Chemistry Frontiers. Roč. 12, č. 4 (2025), s. 1590-1608. ISSN 2052-1553. E-ISSN 2052-1553
Grant CEP: GA MŠMT(CZ) EH22_008/0004607
Institucionální podpora: RVO:61388963
Klíčová slova: zinc phthalocyanine * photodynamic activity * aggregation
Impakt faktor: 6.1, rok: 2023 ; AIS: 0.941, rok: 2023
Způsob publikování: Open access
Web výsledku:
https://doi.org/10.1039/D4QI02834ADOI: https://doi.org/10.1039/d4qi02834a

The characterization of the stability of self-assembled supramolecular systems is critical for numerous applications that rely on non-covalent interactions between the components. However, in phthalocyanines (Pcs), the coordination of ligands to the central metal is typically not accompanied by significant spectral changes, complicating the determination of association constants (K1). In this study, we developed a reliable and widely applicable method based on fluorescence and absorption spectroscopy that allows straightforward determination of K1 for a broad range of ligands, from heterocyclic to purely aliphatic, with weak (K1 similar to 102 M-1) to strong (K1 similar to 107 M-1) binding affinities. The method benefits from the full characterization of unique J-dimers of Pcs, which are formed via coordination between the peripheral substituent of one molecule and the central metal of another Pc in a series of metal octa(dialkylamino)azaphthalocyanines. These J-dimers exhibit significantly red-shifted absorption bands (up to similar to 710 nm) and retain red fluorescence with significant Stokes shifts (similar to 35-40 nm), making them ideal for spectroscopic analysis. The developed method allowed for the direct determination of dimerization constants (KD) by monitoring temperature-induced J-dimer disassembly. The determined KD values ranged from 108 to 1015 M-1, with the bulkiness of the coordinating substituents being the primary factor affecting the dimerization strength. The insights gained could be instrumental in the rational design of self-coordinating supramolecular systems that are important in, for example, energy and electron transfer processes.
Trvalý link: https://hdl.handle.net/11104/0364055
Vědecká data: Zenodo