The study of self-assembly behavior of phthalocyanine-before (PCB) molecules on Au(111) substrate

The PCB molecules have been self-assembled on Au(111) surface and the self-assembly behavior has been studied based on the first principle calculation. The results show that the PCB molecules are antiparallel phase between line and line observed by scanning tunneling microscopy (STM). Moreover, the lattice parameter are matched between the PCB molecules and the Au(111) substrate. Based on the first-principle calculation, it is found that the self-assembly behavior are affected by the molecule–substrate (MS) and molecule–molecule (MM) interactions (cyano coupling force), in which the molecule–substrate (MS) interactions is stronger than that of between the molecules. And the effect of MS interaction plays a dominate role during the PCB molecules self-assembly. This work is helpful to achieve rational design, accurate prediction, and controllable construction of assembled molecular nanostructures.