Empirical equations for the bond energies and vibrational frequencies at chemisorptive bonds on surfaces

Empirical equations derived for bond energies and force constants of gaseous molecules are applied to chemisorptive bonds on surfaces. For two adsorbed atoms from the same family of the periodic table, A and B, the chemisorptive bond energies, E, to the same metal, M, can be approximated by EA-M/EB-M ≈ (EA2/EB2) 1 2, where EA2 and EB2 are the bonds energies of diatomic molecules A2 and B2, respectively The corresponding vibrational frequencies, ν, can be approximated by ν2A-M/ν2B-M ≈ (mB/mA)(FA2/FB2 ) 1 2 · mA and mB are the masses of atoms A and B, respectively;FA2 and FB2 are the force constants of molecules A2 and B2, respectively. These relations are applied to the chemisorption of halogens on metals and showed good agreement with experiment. © 1982.