Ligand Effects on Optical Properties of Small Gold Clusters: A TDDFT Study

    Authors

    S. Goel; K. A. Velizhanin; A. Piryatinski; S. A. Ivanov;S. Tretiak

    Comments

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    Abbreviated Journal Title

    J. Phys. Chem. C

    Keywords

    THEORETICAL CHEMISTRY; VISIBLE LUMINESCENCE; ELECTRONIC STATES; LARGE; MOLECULES; METAL-CLUSTERS; EXCITED-STATES; AB-INITIO; AU2; NANOPARTICLES; EXCHANGE; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, ; Multidisciplinary

    Abstract

    Ligand influence on the excited state structure of small neutral gold clusters (Au-2 and Au-4) has been investigated using Time Dependent Density Functional Theory. We study in detail the absorption profile of bare and ligated small gold clusters in solution modeled with Polarizable Continuum Model. Performance of CAM-B3LYP and TPSS DFT functionals combined with TZVP basis set has been assessed. We found that ligands substantially modify the excited state structure of clusters by eliminating low-lying optically inactive excited states. Depending on the ligand environment, the cluster may gain significant fluorescence efficiency. Our results suggest that small gold clusters ligated with amines will have better fluorescence potential compared to those ligated with phosphine or thiol ligands, in agreement with preliminary experimental data. TPSS fails to describe excited state structure of ligated clusters due to spurious charge-transfer states, thus highlighting the necessity of choosing appropriate quantum-chemistry model for correct excited state description.

    Journal Title

    Journal of Physical Chemistry C

    Volume

    116

    Issue/Number

    5

    Publication Date

    1-1-2012

    Document Type

    Article

    Language

    English

    First Page

    3242

    Last Page

    3249

    WOS Identifier

    WOS:000299985300006

    ISSN

    1932-7447

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