Abrupt change in the structure of self-assembled monolayers upon metal evaporation

摘要

We have studied the interaction of vapor-deposited nickel with thiol-terminated self-assembled monolayers (SAMs) of oligophenylthiolates on Au, which can be considered as model systems for molecular electronics. Instead of usually observed disordering of the molecular layer, a drastic decrease in molecular tilt was observed at the initial stage of the deposition. This was attributed to the formation of Ni-thiol complexes at the SAM-ambient interface. The reorientation resulted in the appearance of transient channels for the metal diffusion into the SAM and to the SAM-substrate interface.