Issue 8, 2017

Bonding trends across the series of tricarbonato-actinyl anions [(AnO2)(CO3)3]4− (An = U–Cm): the plutonium turn

Abstract

Actinyl-tricarbonato anions [(AnO2)(CO3)3]4− (An = U–Cm) in various environments were investigated using theoretical approaches of quantum-mechanics, molecular-mechanics and cluster-models. Cations and solvent molecules in the 2nd coordination sphere affect the equatorial An←Oeq bonds more than the axial An[triple bond, length as m-dash]Oax bonds. Common actinide contraction is found for calculated and experimental axial bond lengths of 92U to 94Pu, though no longer for 94Pu to 96Cm. The tendency of U to Pu forming actinyl(VI) species dwindles away toward Cm, which already features the preferred AnIII/LnIII oxidation state of the later actinides and all lanthanides. The well known change from d-type to typical U–Pu–Cm type and then to f-type behavior is labeled as the plutonium turn, a phenomenon that is caused by f-orbital energy-decrease and f-orbital localization with increase of both nuclear charge and oxidation state, and a non-linear variation of effective f-electron population across the actinide series. Both orbital and configuration mixing and occupation of antibonding 5f type orbitals increase, weakening the AnOax bonds and reducing the highest possible oxidation states of the later actinides.

Graphical abstract: Bonding trends across the series of tricarbonato-actinyl anions [(AnO2)(CO3)3]4− (An = U–Cm): the plutonium turn

Supplementary files

Article information

Article type
Paper
Submitted
14 Oct 2016
Accepted
18 Jan 2017
First published
26 Jan 2017

Dalton Trans., 2017,46, 2542-2550

Bonding trends across the series of tricarbonato-actinyl anions [(AnO2)(CO3)3]4− (An = U–Cm): the plutonium turn

J. Liu, G. P. Chen, W. Huang, D. L. Clark, W. H. E. Schwarz and J. Li, Dalton Trans., 2017, 46, 2542 DOI: 10.1039/C6DT03953G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements