Understanding 2p core-level excitons of late transition metals by analysis of mixed-valence copper in a metal-organic framework

Han Wang; Gregory M Su; Brandon R Barnett; Walter S Drisdell; Jeffrey R Long; David Prendergast

doi:10.1039/d4cp00662c

Understanding 2p core-level excitons of late transition metals by analysis of mixed-valence copper in a metal-organic framework

Phys Chem Chem Phys. 2024 Apr 17;26(15):11980-11987. doi: 10.1039/d4cp00662c.

Authors

Han Wang^{1

2

3}, Gregory M Su^{3

4}, Brandon R Barnett^{5

6}, Walter S Drisdell³, Jeffrey R Long^{5

6

7}, David Prendergast⁸

Affiliations

¹ School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China. wanghan3@shanghaitech.edu.cn.
² Center for Transformative Science, ShanghaiTech University, Shanghai 201210, China.
³ Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁴ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁵ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁶ Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.
⁷ Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA.
⁸ The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.

PMID: 38573245
DOI: 10.1039/d4cp00662c

Abstract

The L_2,3-edge X-ray absorption spectra of late transition metals such as Cu, Ag, and Au exhibit absorption onsets lower in energy for higher oxidation states, which is at odds with the measured spectra of earlier transition metals. Time-dependent density functional theory calculations for Cu²⁺/Cu⁺ reveal a larger 2p core-exciton binding energy for Cu²⁺, overshadowing shifts in single-particle excitation energies with respect to Cu⁺. We explore this phenomenon in a Cu⁺ metal-organic framework with ∼12% Cu²⁺ defects and find that corrections with self-consistent excited-state total energy differences provide accurate XAS peak alignment.