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Vaněčková E, Dahmane M, Forté J, Cherraben S, Pham XQ, Sokolová R, Brémond É, Hromadová M, Lainé PP. Are Redox-Active Centers Bridged by Saturated Flexible Linkers Systematically Electrochemically Independent? Angew Chem Int Ed Engl 2024; 63:e202406299. [PMID: 38772710 DOI: 10.1002/anie.202406299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/17/2024] [Accepted: 05/21/2024] [Indexed: 05/23/2024]
Abstract
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.
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Affiliation(s)
- Eva Vaněčková
- Department of Electrochemistry at the Nanoscale, J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23, Prague, Czech Republic
| | - Mustapha Dahmane
- Université Paris Cité, CNRS, ITODYS, 15 rue J-A de Baïf, F-75013, Paris, France
| | - Jérémy Forté
- Institut Parisien de Chimie Moléculaire, UMR CNRS 8232, Sorbonne Université, 4 place Jussieu, 75005, Paris, France
| | - Sawsen Cherraben
- Université Paris Cité, CNRS, ITODYS, 15 rue J-A de Baïf, F-75013, Paris, France
| | - Xuan-Qui Pham
- Université Paris Cité, CNRS, ITODYS, 15 rue J-A de Baïf, F-75013, Paris, France
| | - Romana Sokolová
- Department of Electrochemistry at the Nanoscale, J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23, Prague, Czech Republic
| | - Éric Brémond
- Université Paris Cité, CNRS, ITODYS, 15 rue J-A de Baïf, F-75013, Paris, France
| | - Magdaléna Hromadová
- Department of Electrochemistry at the Nanoscale, J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23, Prague, Czech Republic
| | - Philippe P Lainé
- Université Paris Cité, CNRS, ITODYS, 15 rue J-A de Baïf, F-75013, Paris, France
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Brémond É, Li H, Pérez-Jiménez ÁJ, Sancho-García JC, Adamo C. Tackling an accurate description of molecular reactivity with double-hybrid density functionals. J Chem Phys 2022; 156:161101. [DOI: 10.1063/5.0087586] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this Communication, we assess a panel of 18 double-hybrid density functionals for the modeling of the thermochemical and kinetic properties of an extended dataset of 449 organic chemistry reactions belonging to the BH9 database. We show that most of DHs provide a statistically robust performance to model barrier height and reaction energies in reaching the “chemical accuracy.” In particular, we show that nonempirical DHs, such as PBE0-DH and PBE-QIDH, or minimally parameterized alternatives, such as ωB2PLYP and B2K-PLYP, succeed to accurately model both properties in a balanced fashion. We demonstrate, however, that parameterized approaches, such as ωB97X-2 or DSD-like DHs, are more biased to only one of both properties.
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Affiliation(s)
- Éric Brémond
- ITODYS, CNRS, Université de Paris, F-75006 Paris, France
| | - Hanwei Li
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Life and Health Sciences (i-CLeHS), F-75005 Paris, France
| | | | | | - Carlo Adamo
- Chimie ParisTech, PSL Research University, CNRS, Institute of Chemistry for Life and Health Sciences (i-CLeHS), F-75005 Paris, France
- Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris, France
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