Evaluating the electronic structure of formal Ln II ions in Ln II (C 5 H 4 SiMe 3 ) 3 1- using XANES spectroscopy and DFT calculations

The isolation of [K(2.2.2-cryptand)][Ln(C H SiMe ) ], formally containing Ln , for all lanthanides (excluding ) was surprising given that +2 oxidation states are typically regarded as inaccessible for most 4f-elements. Herein, X-ray absorption near-edge spectroscopy (XANES), ground-state density fun...

Full description

Saved in:
Bibliographic Details
Published in:Chemical science (Cambridge) 2017-09, Vol.8 (9), p.6076-6091
Main Authors: Fieser, Megan E, Ferrier, Maryline G, Su, Jing, Batista, Enrique, Cary, Samantha K, Engle, Jonathan W, Evans, William J, Lezama Pacheco, Juan S, Kozimor, Stosh A, Olson, Angela C, Ryan, Austin J, Stein, Benjamin W, Wagner, Gregory L, Woen, David H, Vitova, Tonya, Yang, Ping
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The isolation of [K(2.2.2-cryptand)][Ln(C H SiMe ) ], formally containing Ln , for all lanthanides (excluding ) was surprising given that +2 oxidation states are typically regarded as inaccessible for most 4f-elements. Herein, X-ray absorption near-edge spectroscopy (XANES), ground-state density functional theory (DFT), and transition dipole moment calculations are used to investigate the possibility that Ln(C H SiMe ) (Ln = Pr, Nd, Sm, Gd, Tb, Dy, Y, Ho, Er, Tm, Yb and Lu) compounds represented molecular Ln complexes. Results from the ground-state DFT calculations were supported by additional calculations that utilized complete-active-space multi-configuration approach with second-order perturbation theoretical correction (CASPT2). Through comparisons with standards, Ln(C H SiMe ) (Ln = Sm, Tm, Yb, Lu, Y) are determined to contain 4f 5d (Sm ), 4f 5d (Tm ), 4f 5d (Yb ), 4f 5d (Lu ), and 4d (Y ) electronic configurations. Additionally, our results suggest that Ln(C H SiMe ) (Ln = Pr, Nd, Gd, Tb, Dy, Ho, and Er) also contain Ln ions, but with 4f 5d configurations (not 4f 5d ). In these 4f 5d complexes, the -symmetric ligand environment provides a highly shielded 5d-orbital of ' symmetry that made the 4f 5d electronic configurations lower in energy than the more typical 4f 5d configuration.
ISSN:2041-6520
2041-6539
DOI:10.1039/C7SC00825B