1‐Adamantanethiol as a versatile nanografting tool

Abstract

Strategies to regulate the self-assembly of adsorbates to create surface structures with molecular-scale features and organization are of broad interest to nanoscience, biochemistry, and engineering. One approach utilizes molecules with tailored intermolecular interaction strengths and topologies to direct molecular self-assembly as exemplified by the adsorption of 1-adamantanethiol molecules on Au{111} substrates. 1-Adamantanethiolate self-assembled monolayers exhibit decreased packing densities and weaker intermolecular interaction strengths than n-alkanethiolate self-assembled monolayers, which result in their complete displacement upon exposure to n-alkanethiol molecules. Herein, we explore the capabilities of the atomic force microscopy-based lithographic technique, nanografting, to fabricate chemical patterns comprised of 1-adamantanethiolate monolayers. Positive 1-adamantanethiolate patterns are generated by nanografting 1-adamantanethiol molecules into preexisting n-alkanethiolate self-assembled monolayers, and negative 1-adamantanethiolate patterns are created by nanografting n-alkanethiol molecules into preexisting 1-adamantanethiolate self-assembled monolayers. The patterned 1-adamantanethiolate regions are displaced upon exposure to solutions of n-alkanethiol molecules. This two-step nanografting-displacement strategy minimizes pattern dissolution as 1-adamantanethiol molecules do not intercalate into the preexisting self-assembled monolayer during nanografting. 1-Adamantanethiol can be utilized create high-resolution sacrificial chemical patterns with feature sizes beyond those afforded other 1-adamantanethiol patterning strategies for applications such as resists for metallic and organic structures.