Building chessboard-like supramolecular structures on Au(111) surfaces

We investigate an anthracene derivative, 3(5)-(9-anthryl) pyrazole (ANP), self-assembled on the Au(111) surface by means of scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. A chessboard-like network structure composed of ANP molecules is found, covering the whole Au(111) substrate. Our STM results and DFT calculations reveal that the formation of chessboard-like networks originates from a basic unit cell, a tetramer structure, which is formed by four ANP molecules connected through C-H…N hydrogen bonds. The hydrogen bonds inside each tetramer and the molecule-substrate interaction are fundamentally important in providing a driving force for formation of the supramolecular networks.