Issue 47, 2020

The decisive role of 4f-covalency in the structural direction and oxidation state of XPrO compounds (X: group 13 to 17 elements)

Abstract

Lanthanide oxo compounds are of vital importance in lanthanide chemistry, as well as in environmental and materials sciences. Praseodymium, as an exceptional element in lanthanides which can form a +V formal oxidation state (OSf) besides the dominant +III among the 4f-block element, displays the significant participation of the Pr 4f orbitals in bonding interactions which is commonly crucial in stabilizing the high oxidation state of Pr in PrO2+ and NPrO species. Here, we report a systematic theoretical study on the structures and stabilities of a series of XPrO (X: B, Al, C, Si, N, P, As, O, S, F, Cl) compounds along with [XPrO]+ cation (X: O, S) and [X3PrO] complexes (X: F and Cl). This work reveals that Pr is able to achieve the lowest and highest OSf and the OSf exhibits periodic variation from +I in BOPr and AlOPr to +II in SiOPr to +III in CPrO, FPrO, ClPrO and AsPrO to +IV in OPrO and SPrO and even to +V in NPrO, [OPrO]+, [SPrO]+, F3PrO and Cl3PrO. We found that the molecular structures are correlated to the Pr oxidation state due to the highly important 4f orbital in the chemical bonding of the high oxidation state compounds. Thus, not only the electronegativity of the ligand but also the quasi-degenerate Pr valence 4f orbitals, namely energetic covalency, control the oxidation state and play a fundamental role in affecting the electronic structural stability of Pr(V) compounds as well. This work demonstrates the structurally directing role of the f-orbital in the formation of the linear structure and is constructive for achieving the higher oxidation state of a given element by tuning the ligand.

Graphical abstract: The decisive role of 4f-covalency in the structural direction and oxidation state of XPrO compounds (X: group 13 to 17 elements)

Supplementary files

Article information

Article type
Paper
Submitted
06 sep 2020
Accepted
12 nov 2020
First published
13 nov 2020

Phys. Chem. Chem. Phys., 2020,22, 27746-27756

The decisive role of 4f-covalency in the structural direction and oxidation state of XPrO compounds (X: group 13 to 17 elements)

W. Zhang, G. Wang, P. Zhang, W. Zou and S. Hu, Phys. Chem. Chem. Phys., 2020, 22, 27746 DOI: 10.1039/D0CP04700G

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