Building Upon Patterned Organic Monolayers Produced via Catalytic Stamp Lithography

Abstract

Soft lithographic sub-100 nm chemical patterning was demonstrated on organic monolayer surfaces using poly(dimethylsiloxane)-based stamps decorated with Pd nanostructures, structures termed "catalytic stamps". Chemically reactive azide or alkene functionalities were incorporated on oxide-capped silicon surfaces and utilized for patterning via Pd-catalyzed hydrogenation or Heck reactions. The catalytic stamps were soft lithographic stamps based on PDMS with embedded nanoscale palladium catalysts, prepared via block copolymer-based templating. Nanoscale chemical patterns were readily generated on the azide or alkene precursor surfaces simply by applying the Pd catalytic stamps and the reactive molecule, the molecular ink, to the surface, thanks to the highly localized catalytic transformations induced by the patterned, immobilized solid Pd catalysts. A series of successful postfunctionalization reactions on the resulting patterned surfaces further demonstrated the utility of this approach to construct novel designs of nanoarchitectures, with potentially unique and innovative properties.