Insertion of 1,10-decanedithiol in decanethiolate self-assembled monolayers on Au{111}

Abstract

Decanethiolate self-assembled monolayers (SAMs) on Au{111} have been used as host matrices for the molecular insertion of 1,10-decanedithiol from dilute ethanolic solutions into film defect sites. The inserted 1,10-decanedithiolate molecules were observed as protrusions in topographic scanning tunnelling microscopy (STM) images. With this method, each 1,10-decanedithiolate molecule adopts an orientation with a single Ausurface–thiolate bond with the distal thiol termini protruding from the SAM. Subsequent topographic STM images captured the molecular migration of inserted 1,10-decanedithiolate molecules, and this event is attributed either to molecular movement up or down a gold step edge or reconstruction of a gold vacancy island.