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

A series of organic solid states including three salts, two co-crystals, and three hydrates based on tetrafluoroterephthalic acid (H(2)tfBDC) 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)center dot(H(2)tfBDC)] (1), [(DHMPI)(2)center dot(H(2)tfBDC)] (2), [(H-ADMPI(+))(2)center dot(tfBDC(2-))center dot 2(H2O)] (3), [(H-ADMOPI(+))(2)center dot(tfBDC(2-))center dot(H2O)] (4), [(H-DMBI+)(2)center dot(tfBDC(2-))center dot 2(H2O)] (5), [(H-ABI(+))(2)center dot(tfBDC(2-))] (6), [(H-DMP+)center dot(HtfBDC(-))] (7), and [(H-3-CNpy(+))center dot(HtfBDC(-))] (8), were synthesized by solvent evaporation method. Crystal structures analyses show that the F atom of the H(2)tfBDC participates in multiple C-H center dot center dot center dot F hydrogen bond formations, producing different supramolecular synthons. The weak hydrogen bonding C-H center dot center dot center dot F and N-H center dot center dot center dot 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 R-2(2)(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 O-H center dot center dot center dot 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). (C) 2016 Elsevier B.V. All rights reserved.