Observation of outermost surface layer of 4-mercaptohydrocynnamic acid self-assembled film on Au 111/ by Penning ionization electron spectroscopy

Penning ionization electron spectroscopy PIES. and ultraviolet photoelectron spectroscopy UPS. were used to characterize the self-assembled SA.film of 4-mercaptohydrocynnamic acid deposited on Au 111.from aqueous solution. The analysis of the relative band intensity of the Penning spectra suggests that the molecules expose the thiophenyl group outside the film surface, and form a bilayer made up of a hydrogen-bonding network of carboxyl groups. q1999 Elsevier Science B.V. All rights reserved.