The relevance of these issues to bond selective chemistry is quite clear. New, molecular state selective, experiments in this area of surface science are badly needed. The excited beam will be made to impinge on the well-characterized surface of a Ni or Fe crystal. A minimum coverage of 0.0001 should be detectable in this way. We have discovered that the chemisorption energy of the thiol functionality on gold decreases by increasing the size of the hydrocarbon residue attached to the sulphur atom likely because of the repulsion between the metal electrons and the hydrocarbon residue.
Most surface chemistry happens in or on monolayers.
Moreover, monolayers are two-dimensional systems with peculiar physical properties which are especially interesting from the point of view of phase transitions and lattice dynamics. Finally, monolayers of long chain compunds provide excellent models for membranes and have important applications in the field of corrosion protection and chemical sensors. A monoenergetic beam of atoms or synchrotron radiation is produces and made to impinge on the surface to be studied. We have also studied the dependence of the order at the surface on the length of the hydrocarbon chain and the symmetry of the crystalline substrate. Finally, we have studied the growth kinetics of these monolayers, discovering that the formation process involves two steps in which the formation of the equilibrium membrane-like phase is preceded by the formation of at least one lower density phase in which the molecules lay down flat on the surface.