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The quantitative visualizations and comparisons between the four pyrazinamide (PZA) polymorphs (α, β, γ and δ) have been investigated by graphical tools based on three-dimensional Hirshfeld surfaces and two-dimensional fingerprint plots. The comparisons were performed in terms of crystal structure, d, Shape index, Curvedness and d surfaces, and fingerprint plots. The results revealed that the α and γ forms featured with 1D chains and the π···π stacking motifs belong to γ-motif, rich in π···π interactions and form infinite face-to-face stacks, β and δ forms featured with dimer unit and the π···π stacking motifs belong to γ- and herringbone-motif, respectively, the herringbone motif of δ form rich in C-H···π and edge-to-face interactions. We also correlated the phase transformation points of α, β, and δ PZA forms with the ratio of the percentage surface coverage of the N-H···O hydrogen bonds over that of the N-H···N hydrogen bonds, and found a negative correlation. [ABSTRACT FROM AUTHOR]

The compound {[Zn(μ-dicyanamide)(pyrazinamide)](pyrazinamide)} has been synthesized and further characterized by elemental analysis, single-crystal X-ray diffraction, and thermogravimetric analysis. Structural analysis revealed that the dicyanamide anion acted as bridging ligand in a μ-1,5 mode, resulting a polymeric 1-D chain structure. The pairwise N3-H3B···N1 and N9-H9B···N7, N3-H3A···O2 and N9-H9A···O1, N3-H3B···N7 and N9-H9B···N1 multiple hydrogen bonding interactions, impart enhanced stability to supramolecular structures. Hirshfeld surfaces and fingerprint plots were applied to arrive at the same conclusion, which is stabilised mainly by H-H, N-H, O-H interactions. DNA binding studies showed that the compound had interacted with DNA. [ABSTRACT FROM AUTHOR]

We here reported a series of co-crystal structure of pyrazinamide (PZA) with m-hydroxybenzoic acid (MHBA), p-hydroxybenzoic acid (PHBA) and 3,4-dihydroxy benzolic acid (3,4-DHBA) and obtained three co-crystals (co-crystal 1- 3, respectively) under the same conditions. These crystal structures were characterized by single-crystal X-ray diffraction, IR spectra, thermogravimetric analyses, differential scanning calorimetry, and Raman spectrum analysis. The images of single crystal diffraction revealed that 1 was a 1:1 (PZA:MHBA) co-crystal, 2 was a 1:1 (PZA:PHBA) co-crystal, and 3 was a 1:1 (PZA:3,4-DHBA). The strong O-H···O, N-H···O hydrogen bonding interactions between PZA and hydroxyl-substituted benzoic acid primarily made the structure of co-crystals stabilized. Hirshfeld surface and fingerprint plots of the three co-crystals showed that the structures were stabilized by H···H, O-H···O, N-H···O C-H···π, and π···π intermolecular interactions. [ABSTRACT FROM AUTHOR]