Abstract
Self-assembly of molecules on surfaces is a route toward not only creating structures, but
also engineering new chemical reactivity afforded by the intermolecular interactions. 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 S-S
bonds were broken and then reformed to produce new CH3SSCH3 molecules. Theoretical and
experimental evidence support 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.
