Optical response of silver nanoclusters complexed with aromatic thiol molecules: A time-dependent density functional study

We study the effects of chemical bonding on the optical response of Ag _n (n = 4, 6, 8) clusters complexed with aromatic thiol molecules using time-dependent density functional theory (TDDFT). The UV-visible absorption spectra of benzenethiol-doped silver clusters are calculated in an aqueous solution with a long-range corrected density functional. They are compared to those of pure silver clusters. The adsorption of thiophenolate (C₆H₅S^-) and 4-mercaptophenolate (HOC ₆H₄S^-) ions on metal clusters occurs via the thiolate bond leading to a relatively strong stability.