The adsorption site of methoxy and ethoxy on Cu(1 0 0) as determined by vibrational spectroscopy and first principle calculations

In the present work we determine the adsorption site of two polyatomic molecules, methoxy and ethoxy, on Cu(1 0 0). This is accomplished by comparing experimental intramolecular vibrational modes to the corresponding modes calculated by first principle methods. We explore the three different high symmetry adsorption sites on top, bridge and hollow using several different metal clusters to represent the Cu(1 0 0) surface. The experimental results for both methoxy and ethoxy are best reproduced by the most realistic representation of the hollow position, a Cu₅ cluster.