Catalytic Amplification of Patterning via Surface-Confined Ring-Opening Metathesis Polymerization on Mixed Primer Layers Formed by Contact Printing

Thin films of polymers synthesized from strained olefins were formed on Si(100) via ring-opening metathesis polymerization (ROMP) initiated by a Ru−alkylidene catalyst bound to the surface by means of the alkylidene ligands. Specifically, a mixture of 7-octenyltrichlorosilane (3) and octyltrichlorosilane (4) was deposited onto Si/SiO2 surfaces via contact printing, and this assembly was subsequently treated with RuCl2(PCy3)2(CHPh) (1). The resulting surface-tethered Ru alkylidene complex reacts with norbornene derivatives to give thin polymer films. The growth of the polymer film, as monitored by ellipsometry, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM), is strongly influenced by the initial concentration of the catalyst at the surface and by the monomer reactivity. The catalyst concentration at the Si/SiO2 surface was controlled by adjusting the relative ratio of 3 and 4 in the “primer” used in the contact-printing step. These studies revealed that the success of the catalyt...