Redox Properties of Monocyclooctatetraenyl Uranium(IV) and (V) Complexes: Experimental and Relativistic DFT Studies

Abstract : The redox properties of a series of mono(cyclooctatetraenyl) uranium(IV) and (V) complexes [(Cot)(Cp)U(NEt2)2] (1) (Cot = η-C8H8, Cp = η-C5H5) [(Cot)U(OiPr)3] (2), [(Cot)U(NMe2)3] (3), [(Cot)U(N{SiMe3}2)2] (4), [(Cot)U(NEt2)3]– (5), and the cyclopentadienyl compound [(C5Me5)U(NEt2)3] (6) have been investigated using cyclic voltammetry and relativistic density functional theory (DFT). Electrochemical measurements of half-wave potentials in tetrahydrofuran were carried out under strictly anaerobic conditions. The calculations of ionization energies (IE) and electron affinities (EA) of these compounds, related to the UIII/UIV, UIV/UV, and UV/UVI redox systems, revealed a very good linear correlation (r2 = 0.99) between calculated ionization energies at the ZORA/BP86/TZP level and the measured E1/2 half-wave oxidation potentials. A similar good linear correlation between the computed electron affinities and the electrochemical reduction potentials (r2 = 0.98) was obtained. It was found to be crucial to take into account the solvent effect as well as the spin–orbit coupling. The DFT computations permitted the estimation of the oxidation potential of 3 as well as the reduction potential of 5 for which the electrochemical measurement failed. An explanation of the different redox behaviors of the complexes has been given, considering the donating ability of the ligands and the nature of their frontier molecular orbitals (MOs). The molecular orbital analysis underlines the determining role of the metal 5f orbitals, whereas a good correlation is observed between the Nalewajski–Mrozek bond indices and the structural variations related to the redox processes.
Type de document :
Article dans une revue
Organometallics, American Chemical Society, 2017, 36 (19), pp.3841-3853. 〈10.1021/acs.organomet.7b00585〉
Domaine :
Liste complète des métadonnées

Littérature citée [28 références]  Voir  Masquer  Télécharger

https://hal-cea.archives-ouvertes.fr/cea-01593500
Contributeur : Serge Palacin <>
Soumis le : mardi 26 septembre 2017 - 13:30:34
Dernière modification le : vendredi 16 novembre 2018 - 01:36:18
Document(s) archivé(s) le : mercredi 27 décembre 2017 - 13:40:33

Fichier

Berthet_organometallics2017_V0...
Fichiers produits par l'(les) auteur(s)

Identifiants

Citation

Farida Kias, Fatiha Talbi, Aziz Elkechai, Abdou Boucekkine, Didier Hauchard, et al.. Redox Properties of Monocyclooctatetraenyl Uranium(IV) and (V) Complexes: Experimental and Relativistic DFT Studies. Organometallics, American Chemical Society, 2017, 36 (19), pp.3841-3853. 〈10.1021/acs.organomet.7b00585〉. 〈cea-01593500〉

Partager

Métriques

Consultations de la notice

259

Téléchargements de fichiers

137