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

A new kind of low symmetric aromatic tetra-carboxylic acids H(4)BCPIA molecules self-assembled and were regulated by two kinds of pyridine derivatives on the heptanoic acid/HOPG interface. H(4)BCPIA molecule selfassembled 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, H(4)BCPIA dimers formed into honeycomb networks, which PEBP-C4 molecules were trapped in. By observing the influence of the pyridine derivatives on the structures of H(4)BCPIA dimers, the strength of O-H center dot center dot center dot N hydrogen bonds and the meta-dicarboxylic hydrogen bonds were compared. The hydrogen bonding strength of O-H center dot center dot center dot N hydrogen bonds formed by DPE and H(4)BCPIA, O-H center dot center dot center dot O dihydrogen bonds formed by meta-carboxyl groups between H(4)BCPIA, and O-H center dot center dot center dot N hydrogen bonds formed by PEBP-C4 and H(4)BCPIA decreased in order. The investigation of H(4)BCPIA self-assembly structures had great reference value for the meta-carboxyl groups self-assembly behavior.