How Adsorption Geometry Dictates Chiroptical Properties: A Computational Study of l-Cysteine on Au(111) Cluster Models

Understanding chirality transfer in metal nanoclusters is crucial for developing advanced materials with tailored optical properties. This study investigates the chiroptical properties of gold clusters functionalized with l-cysteine using time-dependent density functional theory. By exploring different ligand adsorption configurations, molecular orientations, and intermolecular interactions, we systematically analyze their influence on electronic circular dichroism (ECD) spectra. The results reveal that ligand-induced chirality transfer dominates the ECD response, with hydrogen bonding and molecular orientation playing a significant role in modulating the optical activity. In addition, fragment analysis confirms that metal–ligand interactions strongly contribute to the observed chiroptical effects, demonstrating that controlling ligand arrangement on the gold cluster surface is essential for tuning induced circular dichroism.