We have used plane wave density functional theory (DFT) to determine the structure and relative binding energies of ethoxy, rnono-, di-, and tri-fluoroethoxy adsorbed on Cu(111). The FCC site is found to be the most stable binding site for all four adsorbed species. The orientations of ethoxy and tri-fluoroethoxy on the surface are found to be in good agreement with quantitative predictions based on previous FT-IRAS e,experiments. The orientations of mono- and di-fluoroethoxy on Cu(111) are also presented. (C) 2004 Elsevier B.V. All rights reserved.