Byproduct-Free Route to Aminosiloxane Monolayers on Silicon/Silicon Dioxide

The chemisorption of N-methyl-aza-2,2,4-trimethylsilacyclopentane from either the solution or the vapor phase produces monolayer films on silicon (oxide) substrates. The formation of a covalent siloxane linkage to the surface by this adsorbate is accompanied by ring opening, which produces no byproduct. The resulting secondary amine reacts with maleic anhydride to produce a carboxylic acid-terminated surface, accompanied by the formation of a stable amide bond. These reactions and their products were characterized by a combination of optical ellipsometry, contact-angle goniometry, and X-ray photoelectron spectroscopy.