Y. Tai

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

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.

Engineering of the electronic structure in an aromatic dithiol monomolecular organic insulator

Cross-linking, leading to an insulating quasi-polymeric material, occurs with the initial irradiation-induced modification in films of the monomolecular insulator (1,1′;4′,1″-terphenyl)-4,4″-dimethanethiol, although this is accompanied by a decrease in the gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital.

Intermolecular Band Dispersion for Self-Assembly Monolayers of A Polyphenyl Thiol

We find evidence of intermolecular interactions for a self-assembled monolayer (SAM) formed from a large molecular adsorbate, [1,1′;4′,1″-terphenyl]-4,4″-dimethanethiol, from the dispersion of the molecular orbitals with changing the wave vector k. Both unoccupied and occupied molecular orbitals hybridize to electronic bands, with significant band dispersion that appears to be dependent on structure. The results demonstrate that Blochs theorem can apply to the wave vector dependence of the electronic band structure for monomolecular films formed from a relatively large polyphenyl-based species.