Self-assembly of an oligo( p -phenylenevinylene)-based molecule on an HOPG surface: insights from multi-scale simulation and STM observation.

To gain knowledge of the most important weak interactions for supramolecular self-assembly and observe molecular structure for self-assembled architectures, the two-dimensional self-assembly of an oligo( p -phenylenevinylene)-based molecule (AS-OPV) on highly oriented pyrolytic graphite has been investigated. Accurate atomic configuration for the AS-OPV self-assembled pattern has been identified by means of multi-scale simulation combined with scanning tunneling microscopy (STM) experiments. The weak interactions which contribute to the formation of AS-OPV self-assembly are studied by analysis of non-covalent interactions existing in the system and theoretical calculation of their energy values. Investigation of the molecular structure of self-assembly and STM images at a certain temperature range is performed by molecular dynamics and density functional theory simulations. This work paves the way to explore the contribution of weak interactions for the self-assembly system, as well as providing a reference to observe the possible self-assembled structure at temperatures not convenient for direct experimental observation.