Prepartion And Characterization Of Organic Binary Cocrystal Based On Pyridine And Carboxylic Acid Compounds

Hydrogen bond has a broad application in supermolecular chemistry, functional materials, lifesciences, medical, communication engineering, and so on since it has a advantage of high orientation,various forms of formation, reversible dynamics, molecular and supramolecular self-assembly andmolecular recognition through the non-covalent bond. The study of hydrogen bonds improves in the humancivilization, and also plays an important role in the development of science. On the other hand,pharmaceutical co-crystal, as a solid form with various, abd wide applicable scope, becomes a hot topic inrecent years. Pharmaceutical co-crystal based on pyridine compounds often has high biological activity,low toxicity and high selectivity, attracting more and more attention in the pharmaceutical chemistry.In this paper, we used pyridine and organic carboxylic acid compounds with different substituents asthe synthons to synthesize co-crystal molecules by solvent evaporation and solvothermal, and furtherdetermined their crystal structure, discussed the formation of hydrogen bonds.1. The crystals structures of11co-crystal compounds were successfully prepared,and the effect of thevarious functional groups (hydroxyl, amino, nitro, sulfonic acid, halogen, methyl group and so on), and thedifferent substitutional site on the hydrogen bonds of the crystal structures was explored.2. The X-ray single crystal diffraction technique is used to determine the structure of co-crystalcompounds. Amongst these compounds, the main hydrogen bond is a classic strong O-H...N, N-H...O andO-H...O hydrogen bond. These hydrogen bonds build new supermolecular hydrogen bond network, andplayed a key role in the formation of crystal.3. The influence of the different synthons and functional groups on the melting point of co-crystalcompounds was analyzed. Infrared spectra were determined to characterize the type and the formation ofhydrogen bonds between the pyridine nitrogen atoms and carboxylic acid.4. Four selected model compounds were optimized using the B3LYP/WB97XD method at the6-311++G(d,p) basis siet, and the stable structures were further analysis using the Atoms in molecules (AIM)theroy, and electrostatic potential map to investigate the weak interactions between two synthons.Conformation of synthon plays a different role in the stability of the crystal structure configuration.