Supramolecular assemblies of tetrafluoroterephthalic acid and N-heterocycles via various strong hydrogen bonds and weak CH⋯F interactions: Synthons cooperation, robust motifs and structural diversity

• Eight new multicomponent Hydrogen-bonding organic solids were synthesized.
• The strong and weak hydrogen bonding direct the packing modes of molecular crystals together.
• The F atom of the H2tfBDC participates in multiple CH⋯F hydrogen bonds producing different supramolecular synthons.

A series of organic solid states including three salts, two co-crystals, and three hydrates based on tetrafluoroterephthalic acid (H2tfBDC) and N-bearing ligands (2,4-(1H,3H)-pyrimidine dione (PID), 2,4-dihydroxy-6-methyl pyrimidine (DHMPI), 2-amino-4,6-dimethyl pyrimidine (ADMPI), 2-amino-4,6-dimenthoxy pyrimidine (ADMOPI), 5,6-dimenthyl benzimidazole (DMBI), 2-aminobenzimidazole (ABI), 3,5-dimethyl pyrazole (DMP), and 3-cyanopyridine (3-CNpy)), namely, [(PID)2·(H2tfBDC)] (1), [(DHMPI)2·(H2tfBDC)] (2), [(H-ADMPI+)2·(tfBDC2−)·2(H2O)] (3), [(H-ADMOPI+)2·(tfBDC2−)·(H2O)] (4), [(H-DMBI+)2·(tfBDC2−)·2(H2O)] (5), [(H-ABI+)2·(tfBDC2−)] (6), [(H-DMP+)·(HtfBDC−)] (7), and [(H-3-CNpy+)·(HtfBDC−)] (8), were synthesized by solvent evaporation method. Crystal structures analyses show that the F atom of the H2tfBDC participates in multiple CH⋯F hydrogen bond formations, producing different supramolecular synthons. The weak hydrogen bonding CH⋯F and NH⋯F play an important part in constructing the diversity structures 2–8, except in crystal 1. In complexes 1–3, they present the same synthon R22(8) with different N-heterocyclic compounds, which may show the strategy in constructing the supramolecular. Meanwhile, the complex 3 exhibits a 2D layer, and the independent molecules of water exist in the adjacent layers. In complexes 4 and 5, the water molecules connect the neighboring layers to form 3D network by strong OH⋯O hydrogen bonding. These crystals 1–8 were fully characterized by single-crystal X-ray crystallography, elemental analysis, infrared spectroscopy (IR), and thermogravimetric analysis (TGA).

Hydrogen bonding patterns and the weak hydrogen bonding CH⋯F and NH⋯F in a series of multi-component molecular constructed by tetrafluoroterephthalic acid with N-heterocycles were discussed in the context.Figure optionsDownload as PowerPoint slide