Regulation of a Porphyrin Derivative Containing Two Symmetric Benzoic Acids by Different Pyridines

A porphyrin derivative called 5,15-di­(4-carboxyphenyl)­porphyrin (H2DCPp) with carboxyl groups successfully self-assembled on a highly oriented pyrolytic graphite (HOPG) surface and its co-assembly structures with three kinds of pyridine molecules were investigated by scanning tunneling microscopy (STM) with atomic resolution. H2DCPp arranged in a long-range ordered structure, and both 1,4-bis (pyridin-4-ylethynyl) benzene (BisPy), 4,4′-bipyridine (BP) and 1,3,5-tris­(pyridin-4-ylethynyl) benzene (TPYB) molecules successfully regulated the host molecules as guest molecules. The well-organized model optimized by density functional theory (DFT) calculations reveals the detailed behavior of the assembly characteristics and regulation of porphyrin derivatives, which is helpful for the research and development of solar cells and nanodevices.