Symmetry breaking in ligand-protected gold clusters probed by nonlinear optics†
Abstract
The first hyperpolarizabilities of [Au25(SR)18]−1/0 and Au38(SR)24 clusters were determined by Hyper-Rayleigh Scattering. A strong dependence on the molecular symmetry was observed, and we explore two strategies to destroy the center of inversion in [Au25(SR)18]−1/0, protection by chiral ligands and alloying of the cluster with silver. This may open new avenues to applications of Au : SR clusters in second-order nonlinear optics.