Plasmon-induced indirect charge transfer and vibronic stabilization in 4-nitrobenzenethiol
Hyoungchul Ham1, Jaeyoung Jeong2, Zee Hwan Kim3
1Department of Chemistry, Sungkyunkwan University, Suwon, Republic of Korea.
Communications Chemistry
|June 4, 2026
Summary
This study reveals a quartet excited anionic state (Q1) accessible via plasmon-driven electron attachment to gold-bound 4-nitrobenzenethiol. This state explains nonthermal vibrational excitation observed in plasmon-driven chemistry.
Area of Science:
- Physical Chemistry
- Computational Chemistry
- Surface Science
Background:
- Plasmon-driven reduction of 4-nitrobenzenethiol (4-NBT) involves transient negative ions and vibrational excitation.
- The precise molecular nature of the excited anionic state in this process is not well understood.
Purpose of the Study:
- To investigate the electronically excited anionic state involved in plasmon-driven 4-NBT reduction.
- To elucidate the coupling between hot-electron injection, excited anionic states, and vibrational motion in the Au5-4-NBT complex.
Main Methods:
- Time-dependent density functional theory (TD-DFT) calculations on the Au5-4-NBT complex.
- Analysis of vertical electron attachment (VEA), natural transition orbitals (NTOs), and vibronically resolved one-photon absorption (OPA) and emission (OPE).
Main Results:
- Identification of a low-lying quartet excited anionic state (Q1) accessible under VEA conditions.
- Q1 exhibits mixed local-excitation and charge-transfer character, influenced by gold coordination.
- The NO2 symmetric stretching coordinate significantly impacts access to and decay from Q1, with low-energy crossing regions identified.
Conclusions:
- A molecular-level framework is provided for understanding the transient anionic state and vibrational excitation in plasmon-driven 4-NBT chemistry.
- The study clarifies the role of a specific excited anionic state and its coupling to vibrational modes.
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