3-Fluoiobenzoic acid adsorbed on Au(1 1 1) Au(1 00) and Au(1 1 0) electrodes has been investigated using in situ IR reflection spectroscopy UV-visible reflectivity measurements and differential capacity measurements As determined by IR reflection spectroscopy the vertically adsorbed 3-fluorobenzoate is the predominant species at positive potentials and the flat-lying type is adsorbed at negative potentials In the UV-visible reflectivity measurements the reflectivity changes for the vertically adsorbed and flat-lying 3-fluorobenzoates on the Au(1 0 0) elect ode were observed at different frequency regions No UV-visible reflectivity signal was observed for the Au(1 1 0) electrode and it was proved that the UV-visible reflectivity change has a strong single crystal surface dependence For the vertical configuration a large contribution between the 5d orbital of Au and the 2p orbital of oxygen in 3-fluorobenzoate was found for the cluster model by OFT calculation (C) 2010 Elsevier Ltd All rights reserved