Hydrogen Bonding Assembled 3D Supramolecular Structures Formed by 5-Amino-2,4,6-triiodoisophthalic Acid and N-Heterocyclic Aromatic Ligands

Three salts constructed by 5-amino-2,4,6-triiodoisophthalic acid(ATIPA) with N-heterocycles aromatic coformers such as pyridine tetrazolium, tetramethylpyrazine and cyanuric acid were synthesized by slowing evapora-tion of solvent. X-Ray single crystal analysis shows that hydrogen protons of the carboxyl groups transfer to nitrogen atoms of the N-heterocyclic coformers to form N-H horizontal ellipsis O hydrogen bonds in all the three compounds. A huge amount of H-bonds play significant role in the construction of these compounds and all of them generate 3D structures through strong O-H horizontal ellipsis N, O-H horizontal ellipsis O, N-H horizontal ellipsis O and weak C-H horizontal ellipsis O hydrogen bonds. Moreover, solvent water molecules are indispensable in the formation of compounds 1 and 3, which constitutes different supramolecular synthons to bridge individual molecules and chains to form stable structures. In addition, these crystal structures were further characterized by thermogravimetric analysis and infrared spectroscopy.