Spontaneously Organized Molecular Assemblies. 3. Preparation and Properties of Solution Adsorbed Monolayers of Organic Disulfides on Gold Surfaces

This paper shows that stable, oriented, polyfunctional organic monolayers can be prepared by the spontaneous organization of structurally complex organic disulfides on polycrystalline gold substrates. Chemisorption proceeds to very high coverages, approaching that equivalent to the bulk-phase densities of the adsorbate molecules. The bonding to the surface is also highly specific, inasmuch as the chemisorption of the disulfide moiety is favored greatly over a wide range of other functionality. This latter feature allows the ready preparation of a broad variety of organic surfaces with well-defined microscopic and macroscopic characteristics. Several representative examples of monolayer films are described, their chemical and thermal properties explored, and their structures characterized by several techniques including infrared and photoelectron spectroscopies.