Quadratic Spin-Orbit Mechanism of the Electronic G-Tensor

Overview

Journal J Chem Theory Comput

Publisher American Chemical Society

Specialties Biochemistry
Chemistry

Date 2023 Mar 10

PMID 36896579

Authors

Petra Pikulova

Debora Misenkova

Radek Marek

Stanislav Komorovsky

Jan Novotny

Affiliations

Soon will be listed here.

Abstract

Understanding how the electronic g-tensor is linked to the electronic structure is desirable for the correct interpretation of electron paramagnetic resonance spectra. For heavy-element compounds with large spin-orbit (SO) effects, this is still not completely clear. We report our investigation of quadratic SO contributions to the g-shift in heavy transition metal complexes. We implemented third-order perturbation theory in order to analyze the contributions arising from frontier molecular spin orbitals (MSOs). We show that the dominant quadratic SO term─spin-Zeeman (SO/SZ)─generally makes a negative contribution to the g-shift, irrespective of the particular electronic configuration or molecular symmetry. We further analyze how the SO/SZ contribution adds to or subtracts from the linear orbital-Zeeman (SO/OZ) contribution to the individual principal components of the g-tensor. Our study suggests that the SO/SZ mechanism decreases the anisotropy of the g-tensor in early transition metal complexes and increases it in late transition metal complexes. Finally, we apply MSO analysis to the investigation of g-tensor trends in a set of closely related Ir and Rh pincer complexes and evaluate the influence of different chemical factors (the nuclear charge of the central atom and the terminal ligand) on the magnitudes of the g-shifts. We expect our conclusions to aid the understanding of spectra in magnetic resonance investigations of heavy transition metal compounds.

Citing Articles

Paramagnetic Effects in NMR Spectroscopy of Transition-Metal Complexes: Principles and Chemical Concepts.

Novotny J, Komorovsky S, Marek R Acc Chem Res. 2024; 57(10):1467-1477.

PMID: 38687879 PMC: 11112740. DOI: 10.1021/acs.accounts.3c00786.

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