Using halogen⋯halogen interactions or C/N–H⋯Cl hydrogen bonding to direct crystal packing in tetrachlorophthalic acid with N-heterocyclic compounds

Abstract

In exploring tetrachlorophthalic acid (H₂-tcpH) with a series of N-heterocyclic compounds, eight different types of supramolecular complexes have been obtained, namely, [(H-1,10-phen)·(H-tcpH)·(H₂-tcpH)·(CH₃OH)] (1), [(H-Hatz)·(H-tcpH)] (2), [(H₂-L5)·(H-tcpH)₂] (3), [(H-Hampym)·(H-tcpH)] (4), [(H₂-edm)·(H-tcpH)₂] (5), [(H-ahmp)₂·(tcpH)·2(H₂O)] (6), [(H₂-L7)·(tcpH)·2(H₂O)] (7), and [(H-Bim)·(H-tcpH)·(H₂O)] (8) (in which 1,10-phen = 1,10-phenanthroline, Hatz = 3-amino-1,2,4-triazole, L5 = 1,4-bis[(2-methylimidazole-1-yl)methyl]benzene, Hampym = 2-aminopyrimidine, edm = ethylenediamine, ahmp = 2-amino-4-hydroxy-6-methylpyrimidine, L7 = 1,2-bis[(2-methylimidazole-1-yl)methyl]benzene, Bim = benzimidazole). These eight complexes displayed amusing structural characteristics and a large amount of hydrogen bonding. Of these, crystals 1–5 generated a 3D supramolecular structure through Cl⋯Cl interactions, whilst C–H⋯Cl and N–H⋯Cl hydrogen bonding exists in the 3D construction of complexes 6–8. In addition, all the complexes were fully characterized by single crystal X-ray diffraction analysis, elemental analysis, infrared spectroscopy (IR), and thermogravimetric analysis (TGA).