Determining the bonding orientation of molecular adsorbates on metal surfaces by angle-resolved photoemission

The application of symmetry and selection rules to valence band angle resolved photoemission of molecular adsorbates on surfaces will be reviewed. Determining the bonding orientation by angle resolved photoemission was initially applied to simple molecular adsorbate systems like CO and N-2. The characterization of the preferential bonding orientations of much larger molecular adsorbates has proved to be equally successful. This paper provides demonstrations that these simple rules for photoemission can be applied to increasingly complex adsorbate systems. There exist opportunities to investigate the surface chemistry of large molecules using photoemission - at a time when intellectual investment in technical improvements to photoemission are bearing fruit.