Abstract
Metal nanoclusters can be synthesized in various sizes and shapes and are typically protected with ligands to stabilize them. These ligands can also be used to tune the plasmonic properties of the clusters as the absorption spectrum of a protected cluster can be significantly altered compared to the bare cluster. In this paper, we computationally investigate the influence of thiolate ligands on the plasmonic intensity for silver, gold and alloy clusters. Using time-dependent density functional theory with tight-binding approximations, TD-DFT+TB, we show that this level of theory can reproduce the broad experimental spectra of Au144(SR)60 and Ag53Au91(SR)60 (R = CH3) compounds with satisfactory agreement. As TD-DFT+TB does not depend on atom-type parameters we were able to apply this approach on large ligand-protected clusters with various compositions. With these calculations we predict that the effect of ligands on the absorption can be a quenching as well as an enhancement. We furthermore show that it is possible to unambiguously identify the plasmonic peaks by the scaled Coulomb kernel technique and explain the influence of ligands on the intensity (de-)enhancement by analyzing the plasmonic excitations in terms of the dominant orbital contributions.
| Original language | English |
|---|---|
| Pages (from-to) | 17929-17938 |
| Number of pages | 10 |
| Journal | Physical Chemistry Chemical Physics |
| Volume | 23 |
| Issue number | 33 |
| Early online date | 11 Aug 2021 |
| DOIs | |
| Publication status | Published - 7 Sept 2021 |
Bibliographical note
Funding Information:We acknowledge the developer group of Software for Chemistry & Materials (SCM) and computing resources of VU University of Amsterdam. We would like to thank Prof. A. Dass for sharing the experimental data. N. A. acknowledges financial support from Student Affair of Ministry of Science and Technology of Iran. J. P. acknowledges funding by the Austrian Science Fund (FWF):J 4177-N36. Z. J. acknowledges the Holland Research School for Molecular Chemistry for a fellowship.
Publisher Copyright:
© the Owner Societies.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
Funding
We acknowledge the developer group of Software for Chemistry & Materials (SCM) and computing resources of VU University of Amsterdam. We would like to thank Prof. A. Dass for sharing the experimental data. N. A. acknowledges financial support from Student Affair of Ministry of Science and Technology of Iran. J. P. acknowledges funding by the Austrian Science Fund (FWF):J 4177-N36. Z. J. acknowledges the Holland Research School for Molecular Chemistry for a fellowship.
| Funders | Funder number |
|---|---|
| Ministry of Science and Technology, Israel | |
| Holland Research School of Molecular Chemistry | |
| Austrian Science Fund | J 4177, J 4177-N36 |