Reflection absorption infrared spectroscopy and the structure of molecularadsorbates on metal surfaces

Infrared (IR) spectroscopy is widely used to identify molecular adsorbates that form on metals in the course of surface chemical reactions. Because DR spectroscopy is one of the few surface-sensitive probes that provide molec ule-specific information without perturbing the chemisorbed state, there is great interest in extracting as much structural information from the spect ra as possible. The various ways IR spectroscopy is used to determine the s tructure of molecular adsorbates, from strictly qualitative interpretations based on symmetry selection rules to the use of ab initio electronic struc ture calculations to predict the IR spectrum of a chemisorbed molecule, are reviewed.