Far-infrared spectra of well-defined thiolate-protected gold clusters†
The far infrared spectra of a series of well-defined gold clusters covered with 2-phenylethanethiolate were studied. The spectra of the clusters are different but the differences are subtle. The Au–S stretching vibrations give rise to bands around 300 cm−1 and below. The relative intensity of these bands changes but they shift only slightly for different clusters. A low-frequency band was identified, which is sensitive to the conformation (trans/gauche) of the 2-phenylethanethiolate ligand.