Near-Infrared Spectrum of the First Excited State of Au
| العنوان: | Near-Infrared Spectrum of the First Excited State of Au |
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| المؤلفون: | Marko, Förstel, Kai, Pollow, Taarna, Studemund, Otto, Dopfer |
| المصدر: | Chemistry (Weinheim an Der Bergstrasse, Germany) |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Communication, structure elucidation, Hot Paper, photodissociation, gold, electronic structure, cations, Communications |
| الوصف: | Au2 + is a simple but crucial model system for understanding the diverse catalytic activity of gold. While the Au2 + ground state (X2Σg +) is understood reasonably well from mass spectrometry and computations, no spectroscopic information is available for its first excited state (A2Σu +). Herein, we present the vibrationally resolved electronic spectrum of this state for cold Ar‐tagged Au2 + cations. This exceptionally low‐lying and well isolated A2Σ(u) +←X2Σ(g) + transition occurs in the near‐infrared range. The observed band origin (5738 cm−1, 1742.9 nm, 0.711 eV) and harmonic Au−Au and Au−Ar stretch frequencies (201 and 133 cm−1) agree surprisingly well with those predicted by standard time‐dependent density functional theory calculations. The linearly bonded Ar tag has little impact on either the geometric or electronic structure of Au2 +, because the Au2 +⋅⋅⋅Ar bond (∼0.4 eV) is much weaker than the Au−Au bond (∼2 eV). As a result of 6 s←5d excitation of an electron from the antibonding σu * orbital (HOMO‐1) into the bonding σg orbital (SOMO), the Au−Au bond contracts substantially (by 0.1 Å). The Au2 + cation: The high‐resolution near‐infrared spectrum of the lowest excited electronic state of this simple diatomic cation recorded by Ar‐tagging photodissociation exhibits a surprisingly simple vibronic structure. Analysis by standard TD‐DFT calculations provides the first spectroscopic information about the chemical bond in Au2 + in both the ground and excited electronic states. |
| تدمد: | 1521-3765 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=pmid________::d7228c815a893d8c8fbeefed3afc6331 https://pubmed.ncbi.nlm.nih.gov/34423877 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.pmid..........d7228c815a893d8c8fbeefed3afc6331 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15213765 |
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