Far-IR Spectra of Small Neutral Gold Clusters in the Gas Phase

Abstract

Abstract Vibrational spectra of small neutral gold clusters containing up to 8 Au atoms are measured in the far-infrared (46–222 cm – 1 ) via photodissociation of their complexes with krypton atoms. Comparisons with calculated IR spectra for bare Au n clusters using density functional theory allow for structural assignment. For these small sizes, all clusters are found to be planar and of comparably high symmetry. For Au 6 no data is available, as this cluster size is not detected in the photoionization mass spectra due to its high ionization energy. The structures assigned are for n = 4: rhombus (D 2 h ); 5: trapezoid (C 2 v ); 7: edge-capped triangle (C s ), 8: 4-fold edge-capped square (D 4 h ).