Assembly and electronic structure of octithiophene on Au(1Â 1Â 1)

► Octithiophene adsorbed on Au(1 1 1) forms well-ordered, closed packed films. ► Molecules adopt a tilted geometry with respect to the surface plane permitting intermolecular π-π-interaction. ► Energetic positions of unoccupied molecular states (LUMOs). ► Weak adsorbate/substrate-interaction.