0587603 - ÚFCH JH 2025 RIV DE eng J - Článek v odborném periodiku
Vaněčková, Eva - Dahmane, M. - Forté, J. - Cherraben, S. - Pham, X. Q. - Sokolová, Romana - Brémond, É. - Hromadová, Magdaléna - Lainé, P. P.
Are Redox-Active Centers Bridged by Saturated Flexible Linkers Systematically Electrochemically Independent?
Angewandte Chemie - International Edition. Roč. 63, č. 31 (2024), č. článku e202406299. ISSN 1433-7851. E-ISSN 1521-3773
Grant CEP: GA ČR(CZ) GA21-13458S; GA MŠMT(CZ) 8J21FR016; GA MŠMT EH22_008/0004558
Institucionální podpora: RVO:61388955
Klíčová slova: computational chemistry * London dispersion forces * molecular electrochemistry * pyridinium * structure–activity relationship
Obor OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)
Impakt faktor: 16.6, rok: 2022
Způsob publikování: Open access
https://onlinelibrary.wiley.com/doi/10.1002/anie.202406299

The extent to which electrophores covalently bridged by a saturated linker are electrochemically independent was investigated considering the charge/spin duality of the electron and functionality of the electrophore as a spin carrier upon reduction. By combining computational modeling with electrochemical experiments, we investigated the mechanism by which tethered electrophores react together within 4,4′-oligo[n]methylene-bipyridinium assemblies (with n=2 to 5). We show that native dicationic electrophores (redox state Z=+2) are folded prior to electron injection into the system, allowing the emergence of supra-molecular orbitals (supra-MOs) likely to support the process of the reductive σ bond formation giving cyclomers. Indeed, for Z=+2, London Dispersion (LD) forces contribute to flatten the potential energy surface such that all-trans and folded conformers are approximately isoenergetic. Then, upon one-electron injection, for radical cations (Z=+1), LD forces significantly stabilize the folded conformers, except for the ethylene derivative deprived of supra-MOs. For radical cations equipped with supra-MOs, the unpaired electron is delocalized over both heterocycles through space. Cyclomer completion (Z=0) upon the second electron transfer occurs according to the inversion of redox potentials. This mechanism explains why intramolecular reactivity is favored and why pyridinium electrophores are not independent.
Trvalý link: https://hdl.handle.net/11104/0354735