Modeling the photosensitizing properties of thiolate-protected gold nanoclusters

Abstract

An accurate computational strategy for studying the structural, redox and optical properties of thiolated gold nanoclusters (GNCs) using (Time-Dependent) Density Functional Theory is proposed. The influence of the pseudopotential/basis set, solvent description and the choice of the functional has been investigated to model the structural and electronic properties of the Au₂₅(SR)₁₈⁻ system, with R being an organic ligand. This study aims to describe with a comparable precision both the GNC and the organic ligands and rationalize the effect of coating on different GNC properties. Two differently coated GNCs have been considered: the system with R = CH₂CH₂Ph and the GNC coated with 17 alkyl chains (C₆H₁₃) and functionalized by one fluorophore pyrene derivative (CH₂CH₂(NH)(CO)Py). The computational protocol we propose should then be used to design more efficient metal cluster-sensitized solar cells.