Polymorphism in self-assembled structures of 9-anthracene carboxylic acid on Ag(111).

ABSTRACT: Surface self-assembly process of 9-anthracene carboxylic acid (AnCA) on Ag(111) was investigated using STM. Depending on the molecular surface density, four spontaneously formed and one annealed AnCA ordered phases were observed, namely a straight belt phase, a zigzag double-belt phase, two simpler dimer phases, and a kagome phase. The two high-density belt phases possess large unit cells on the scale length of 10 nm, which are seldom observed in molecular self-assembled structures. This structural diversity stems from a complicated competition of different interactions of AnCA molecules on metal surface, including intermolecular and molecular-substrate interactions, as well as the steric demand from high molecular surface density.

SUBMITTER: Lu C 

PROVIDER: S-EPMC3397498 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature