Two-dimensional self-assembly and co-assembly of two tetracarboxylic acid derivatives investigated by STM.

In this work, the two-dimensional self-assembly and co-assembly behaviors of two tetracarboxylic acid derivatives (H 4 BDETP and H 4 BTB) were investigated by scanning tunneling microscopy (STM). H 4 BDETP molecules self-assembled into linear nanostructures, and H 4 BTB molecules formed lamellar and tetragonal nanostructures. The formation of a H 4 BDETP/H 4 BTB co-assembly nanostructure was closely related to the deposition sequence of H 4 BDETP and H 4 BTB on highly oriented pyrolytic graphite (HOPG). The introduction of H 4 BTB into the self-assembly system of H 4 BDETP resulted in the emergence of the H 4 BDETP/H 4 BTB nanostructure, while the addition of H 4 BDETP had no effect on the self-assembly system of H 4 BTB and a H 4 BDETP/H 4 BTB co-assembly nanostructure was not obtained.