Collective Reactivity of Molecular Chains Self-Assembled on a Surface

摘要

Self-assembly of molecules on surfaces is a route toward not only creating structures, but also engineering chemical reactivity afforded by the intermolecular interactions. Dimethyldisulfide (CH3SSCH3) molecules self- assemble into linear chains on single-crystal gold surfaces. Injecting low- energy electrons into individual molecules in the self-assembled structures with the tip of a scanning tunneling microscope led to a propagating chemical reaction along the molecular chain as sulfur--sulfur bonds were broken and then reformed to produce new CH3SSCH3 molecules. Theoretical and experimental evidence supports a mechanism involving electron attachment followed by dissociation of a CH3SSCH3 molecule and initiation of a chain reaction by one or both of the resulting CH3S intermediates.