Tuning the locus of oxidation in ...
Document type :
Article dans une revue scientifique: Article original
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Title :
Tuning the locus of oxidation in Cu-diamido-diphenoxo complexes: From Cu(III) to Cu(II)-phenoxyl radical
Author(s) :
Eckshtain-Levi, Meital [Auteur]
Bar-Ilan University [Israël]
Lavi, Ronit [Auteur]
Bar-Ilan University [Israël]
Arora, Himanshu [Auteur]
Bar-Ilan University [Israël]
Orio, Maylis [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Benisvy, Laurent [Auteur]
Bar-Ilan University [Israël]
Bar-Ilan University [Israël]
Lavi, Ronit [Auteur]
Bar-Ilan University [Israël]
Arora, Himanshu [Auteur]
Bar-Ilan University [Israël]
Orio, Maylis [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Benisvy, Laurent [Auteur]
Bar-Ilan University [Israël]
Journal title :
Inorganica Chimica Acta
Volume number :
481
Pages :
143-150
Publication date :
2018-09
HAL domain(s) :
Chimie/Chimie théorique et/ou physique
English abstract : [en]
While N2O2 tetraanionic ligands containing a strong N-amidate σ-donor are generally assumed to stabilise metal high valence states, we herein have shown that, in dianionic Cu(II)-diamido-diphenoxo complexes, H-bonding and ...
Show more >While N2O2 tetraanionic ligands containing a strong N-amidate σ-donor are generally assumed to stabilise metal high valence states, we herein have shown that, in dianionic Cu(II)-diamido-diphenoxo complexes, H-bonding and electronic effects on the phenolate groups may modulate the electronic structure of their oxidised species from Cu(III) to Cu(II)-phenoxyl radical complexes; and so in the negative potential range. We observe that electron-poor phenolate complexes 22− and 32− oxidise to Cu(III) species, whereas electron rich phenolate complex 12− oxidises to a Cu(II)-phenoxyl radical. Our DFT results suggest that π-electron-rich phenolate rings in 12− are responsible for an increase of the HOMO orbital energy, bringing the HOMO-SOMO gap small enough to favour a ligand-based oxidation process. Further DFT-calculations have also shown that upon changing the o,p-phenol substituent from electron-widthdrawing groups (NO2) to electron-donating ones (OMe), the favoured oxidised state switches from Cu(III) to Cu(II)-radical. These results emphasize the use of the versatile diamido-diphenoxo backbone as a promising way to novel GO-chemical models, as well as molecular switches.Show less >
Show more >While N2O2 tetraanionic ligands containing a strong N-amidate σ-donor are generally assumed to stabilise metal high valence states, we herein have shown that, in dianionic Cu(II)-diamido-diphenoxo complexes, H-bonding and electronic effects on the phenolate groups may modulate the electronic structure of their oxidised species from Cu(III) to Cu(II)-phenoxyl radical complexes; and so in the negative potential range. We observe that electron-poor phenolate complexes 22− and 32− oxidise to Cu(III) species, whereas electron rich phenolate complex 12− oxidises to a Cu(II)-phenoxyl radical. Our DFT results suggest that π-electron-rich phenolate rings in 12− are responsible for an increase of the HOMO orbital energy, bringing the HOMO-SOMO gap small enough to favour a ligand-based oxidation process. Further DFT-calculations have also shown that upon changing the o,p-phenol substituent from electron-widthdrawing groups (NO2) to electron-donating ones (OMe), the favoured oxidised state switches from Cu(III) to Cu(II)-radical. These results emphasize the use of the versatile diamido-diphenoxo backbone as a promising way to novel GO-chemical models, as well as molecular switches.Show less >
Language :
Anglais
Audience :
Internationale
Popular science :
Non
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Submission date :
2021-11-16T08:23:40Z
2024-02-14T09:35:49Z
2024-02-14T09:35:49Z