Control of alkanethiolate monolayer structure using vapor-phase annealing.

We describe an annealing procedure for self-assembled monolayers (SAMs) that uses vapor-phase molecules to modify the local domain structure. Existing SAMs of decanethiolate on Au{111} were annealed using vapor-phase dodecanethiol molecules, so that the original and newly introduced molecules could be distinguished using scanning tunneling microscopy (STM). Molecules deposited from the vapor phase inserted at existing monolayer defect sites and domain boundaries, and at substrate step edges forming discrete network-like domains.