Redox properties of biscyclopentadienyl uranium(V) imido-halide complexes: a relativistic DFT study

• Published in: Journal of molecular modeling 2014-06, Vol.20 (6), p.2294-2294, Article 2294
• Main Authors: Elkechai, Aziz, Kias, Farida, Talbi, Fazia, Boucekkine, Abdou
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemical Sciences; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Computer Simulation; Electrons; Energy Transfer; Halogens - chemistry; Inorganic chemistry; Linear Models; Models, Biological; Models, Chemical; Molecular Medicine; Molecular Structure; Organometallic Compounds - chemistry; Original Paper; Oxidation-Reduction; Structure-Activity Relationship; Theoretical and Computational Chemistry; Topical Collection QUITEL 2013; Uranium - chemistry
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-014-2294-5

Calculations of ionization energies (IE) and electron affinities (EA) of a series of biscyclopentadienyl imido-halide uranium(V) complexes Cp* 2 U(=N–2,6– i Pr 2 –C 6 H 3 )(X) with X = F, Cl, Br, and I, related to the U IV /U V and U V /U VI redox systems, were carried out, for the first time, using density functional theory (DFT) in the framework of the relativistic zeroth order regular approximation (ZORA) coupled with the conductor-like screening model (COSMO) solvation approach. A very good linear correlation ( R 2  = 0.993) was obtained, between calculated ionization energies at the ZORA/BP86/TZP level, and the experimental half-wave oxidation potentials E 1/2 . A similar linear correlation between the computed electron affinities and the electrochemical reduction U IV /U III potentials ( R 2  = 0.996) is obtained. The importance of solvent effects and of spin-orbit coupling is definitively confirmed. The molecular orbital analysis underlines the crucial role played by the 5f orbitals of the central metal whereas the Nalewajski-Mrozek (N–M) bond indices explain well the bond distances variations following the redox processes. The IE variation of the complexes, i.e. , IE(F)