Prediction And Interpretation Of Transition Metal X-ray Spectra Using Real-time Time-dependent Density Functional Theory

Yi, Jun

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https://hdl.handle.net/2142/116553 Copy

Description

Title

Prediction And Interpretation Of Transition Metal X-ray Spectra Using Real-time Time-dependent Density Functional Theory

Author(s)

Yi, Jun

Contributor(s)

• Zhu, Ying
• Lin, Zhou

Issue Date

2022-06-21

Keyword(s)

Mini-symposium: Benchmarking in Spectroscopy

Abstract

\begin{wrapfigure}{l}{0pt} \includegraphics[scale=0.35]{ISMS-6050r.eps} \end{wrapfigure} Many transition metal complexes are popular catalysts for homogeneous organic synthesis. Their instantaneous geometric and electronic configurations and roles in the reaction mechanisms can be directly probed by {\it in-situ} K-edge X-ray absorption near-edge structure (XANES) spectroscopy. First-principles modeling is indispensable to translate the frequencies and lineshapes of K-edge absorptions into orbital and structural configurations. In the present study, we performed real-time time-dependent density functional theory (RT-TDDFT) calculations for (2,6-dimethylphenyl)imino)vanadium(V) trichloride and its methyl-substituted derivatives, and obtained time-dependent electronic densities and transition dipole moments by solving the time-dependent Kohn--Sham equations under an applied electromagnetic field. Compared to traditional linear-response TDDFT (LR-TDDFT), RT-TDDFT allows a significant rearrangement of electronic densities after photoexcitations and provides a broadband spectrum in the frequency domain after the Fourier transform. Based on our RT-TDDFT calculations, we managed to reproduce the pre-edge peaks for these species and assigned them to the dipole-allowed transitions of electrons from $1s$ orbital to the $3d4p$ hybridized orbitals of vanadium. Both characters align with the results from LR-TDDFT. In addition, RT-TDDFT leads to important features from the shoulder peaks, which correspond to the dipole-allowed, density-rearranging transitions of electrons from $1s$ orbital of vanadium to its $4p$ orbitals or the $3p$ orbitals of chlorine. These shoulder peak features have never been provided by LR-TDDFT. From the present study, we provided a proof-of-concept that the next-generation RT-TDDFT approach is a versatile and powerful computational tool for the prediction and interpretation of X-ray spectroscopy of transition metal complexes.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116553

DOI

https://doi.org/10.15278/isms.2022.TB06

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Copyright 2022 held by the authors

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