Assessing Covalency in Cerium and Uranium Hexachlorides: A Correlated Wavefunction and Density Functional Theory Study

Inorganics

Reece Beekmeyer¹  Andrew Kerridge¹  Stephen Mansell² 

[1] Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK; E-Mail:;Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK; E-Mail

关键词: covalency;    cerium;    uranium;    CASSCF;    electron density;    QTAIM;    DFT;   

DOI  :  10.3390/inorganics3040482

来源: mdpi

【 摘 要 】

The electronic structure of a series of uranium and cerium hexachlorides in a variety of oxidation states was evaluated at both the correlated wavefunction and density functional (DFT) levels of theory. Following recent experimental observations of covalency in tetravalent cerium hexachlorides, bonding character was studied using topological and integrated analysis based on the quantum theory of atoms in molecules (QTAIM). This analysis revealed that M–Cl covalency was strongly dependent on oxidation state, with greater covalency found in higher oxidation state complexes. Comparison of M–Cl delocalisation indices revealed a discrepancy between correlated wavefunction and DFT-derived values. Decomposition of these delocalisation indices demonstrated that the origin of this discrepancy lay in ungerade contributions associated with the f-manifold which we suggest is due to self-interaction error inherent to DFT-based methods. By all measures used in this study, extremely similar levels of covalency between complexes of U and Ce in the same oxidation state was found.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.