Bromination-Enhanced Chiral Interactions for Triphenylamine on Au and Ag(111)

Abstract

Controlled intermolecular steric interactions within self-assembled structures of chiral molecules are crucial for developing future spintronics and polarization devices. Here, we present that chiral-ordered assembly of brominated triphenylamine (TBPA) on Au(111) and Ag(111) surfaces is achieved by bromination-enhanced interactions between neighboring molecules, which has been characterized by scanning tunneling microscopy. For TBPA, the propeller-shaped conformation gives rise to two chiral enantiomers. In the self-assembled structures of TBPA formed on both Au(111) and Ag(111), we find that the chiral recognition is attributed to the stereoselective interactions between neighboring molecules, which are enhanced by the attractive bromophenyl–bromophenyl interactions. We also discuss the influence of substrate surfaces on the chiral-ordered assembly of TBPA. This study provides valuable insights into the role of bromo substituents in controlling the steric interactions of chiral molecules.