Theoretical Insights into the Origin of Photoluminescence of Au(SR) Nanoparticles.
Understanding fundamental behavior of luminescent nanomaterials upon photoexcitation is necessary to expand photocatalytic and biological imaging applications. Despite the significant amount of experimental work into the luminescence of Au(SR) clusters, the origin of photoluminescence in these clust...
| Publicado en: | Journal of the American Chemical Society Vol. 138; no. 35; pp. 11202 - 11211 |
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| Autores principales: | , |
| Formato: | Artículo |
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American Chemical Society
9/7/2016
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=118366637&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 118366637 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 9/7/2016 vid: 138 iid: 35 pid: 997 pub: American Chemical Society artinfo: ui: 118366637 10.1021/jacs.6b05293 ppf: 11202 ppct: 9 formats: tig: atl: Theoretical Insights into the Origin of Photoluminescence of Au(SR) Nanoparticles. aug: au: Weerawardene, K. L. Dimuthu M. Aikens, Christine M. affil: Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States su: Nanoparticle synthesis Gold nanoparticle synthesis Photoexcitation Density functional theory Electronic structure Photoluminescence sug: subj: Nanoparticle synthesis Gold nanoparticle synthesis Photoexcitation Density functional theory Electronic structure Photoluminescence ab: Understanding fundamental behavior of luminescent nanomaterials upon photoexcitation is necessary to expand photocatalytic and biological imaging applications. Despite the significant amount of experimental work into the luminescence of Au(SR) clusters, the origin of photoluminescence in these clusters still remains unclear. In this study, the geometric and electronic structural changes of the Au(SR) (R = H, CH, CHCH, CHCHCH) nanoclusters upon photoexcitation are discussed using time-dependent density functional theory (TD-DFT) methods. Geometric relaxations in the optimized excited states of up to 0.33 Å impart remarkable effects on the energy levels of the frontier orbitals of Au(SR) nanoclusters. This gives rise to a Stokes shift of 0.49 eV for Au(SH) in agreement with experiments. Even larger Stokes shifts are predicted for longer ligands. Vibrational frequencies in the 75-80 cm range are calculated for the nuclear motion involved in the excited-state nuclear relaxation; this value is in excellent agreement with vibrational beating observed in time-resolved spectroscopy experiments. Several excited states around 0.8, 1.15, and 1.25 eV are calculated for the Au(SH) nanocluster. Considering the typical underestimation of DFT excitation energies, these states are likely responsible for the emission observed experimentally in the 1.15-1.55 eV range. All excited states arise from core-based orbitals; charge-transfer states or other "semi-ring" or ligand-based states are not implicated. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2016 holdings: @attributes: islocal: N |
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