THE ADSORPTION AND BONDING OF METHANETHIOL ON ALUMINUM

To further establish the nature of thiol adsorbate-species, and of the ir surface-bonding, the adsorption of methanethiol has been investigat ed on polycrystalline aluminium, using UPS, XPS and DELTAphi. The chem isorption proceeds through the loss of the thiol hydrogen, resulting i n the corresponding mercaptide (as shown before also on copper). An as signment of the adsorbate-induced bands is made utilising previously d eveloped techniques - an MO description of the ''precursor'' molecule, and the qualitative surface-molecule model for the adsorbate-substrat e interaction. The latter is thus shown not to be confined just to cop per, but to have general applicability. Comparison is also made of CH3 S and CH3O bonding on Al and Cu, and its possible relationship to cata lysis.