The self-assembly of a low symmetric aromatic carboxylic acid with meta-carboxyl groups regulated by pyridine derivatives

Abstract A new kind of low symmetric aromatic tetra-carboxylic acids H4BCPIA molecules self-assembled and were regulated by two kinds of pyridine derivatives on the heptanoic acid/HOPG interface. H4BCPIA molecule self-assembled into dimers as basic units through meta-carboxyl groups and formed into networks with quadrilateral cavities. With the participation of pyridine derivatives, the dimers were broken by DPE molecules and reformed into zigzag lines. After introducing PEBP-C4 molecules, H4BCPIA dimers formed into honeycomb networks, which PEBP-C4 molecules were trapped in. By observing the influence of the pyridine derivatives on the structures of H4BCPIA dimers, the strength of O–H•••N hydrogen bonds and the meta-dicarboxylic hydrogen bonds were compared. The hydrogen bonding strength of O–H•••N hydrogen bonds formed by DPE and H4BCPIA, O–H•••O dihydrogen bonds formed by meta-carboxyl groups between H4BCPIA, and O–H•••N hydrogen bonds formed by PEBP-C4 and H4BCPIA decreased in order. The investigation of H4BCPIA self-assembly structures had great reference value for the meta-carboxyl groups self-assembly behavior.