Chiral Transcription from Chiral Au Nanowires to Self-Assembled Monolayers of Achiral Azobenzene Derivatives

Chiral transcription from chiral inorganic nanoobjects to achiral organic molecules is a fascinating topic. In this study, chiral transcription was demonstrated using helically controlled Au nanowires (NWs) and achiral azobenzene derivatives with thiol moieties as the terminal group. The azobenzene derivatives mAZonSH can form a self-assembled monolayer on helical Au NWs through thiol-Au bonding. UV-Vis spectroscopy revealed that mAZonSH in the self-assembled monolayer forms H-aggregates. The self-assembled monolayers on the right- and left-handed Au NWs showed opposing circular dichroism (CD) signals derived from the azobenzene chromophore. This result indicates that chiral transcription from the helical Au NWs to the azobenzene derivatives was successfully accomplished by the self-assembly of achiral mAZonSH. Furthermore, we demonstrated that the CD responses of mAZonSH are independent of the tail (m) and spacer (n) alkyl lengths.