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The synthesis and crystal structures of the molecular salts of 4-(4-nitrophenyl)piperazine with trifluoroacetate, namely, 4-(4-nitrophenyl)piperazin-1-ium trifluoroacetate, C10H14N3O2 +·C2F3O2 − (I), and with trichloroacetate, namely, 4-(4-nitrophenyl)piperazin-1-ium trichloroacetate, C10H14N3O2 +·C2Cl3O2 −, (II), are reported and compared. A partial positional disorder of the anions was found. In both structures, the piperazine rings adopt a chair conformation, whereas the positions of the nitrophenyl group on the piperazine ring differ from bisectional in (I) to equatorial in (II). In both structures, the supramolecular assemblies are mono-periodic on the basis of the chain-of-rings motifs supported by aromatic π–π interactions. Hirshfeld surface analysis was used to explore the intermolecular close contacts in both crystals. The most dominant contacts of the Hirshfeld surface of the cation–anion pairs of the asymmetric units are O...H/H...O, and those with a contribution of halogen atoms: F...H/H...F in (I) and Cl...H/H...Cl in (II), respectively.

The crystal structures of miconazole {MIC, C18H14Cl4N2O, systematic name (RS)-1-[2-(2,4-dichlorobenzyloxy)-2-(2,4-dichlorophenyl)ethyl]-1H-imidazole}, its ethanol monosolvate (C18H14Cl4N2O·C2H5OH) and its hemihydrate (C18H14Cl4N2O·0.5H2O) were compared. A detailed comparison of the molecular conformation of the miconazole molecules showed a structural similarity of the solvate forms, whereas the unsolvated form is related to the gas-phase structure. This suggests that the molecular conformation of miconazole is influenced by solvent molecules. The crystal architectures of the considered solvatomorphs are differentiated by the intermolecular interactions formed by ethanol and water molecules. The structural studies are enriched by Hirshfeld surface and energy framework analysis. The pairwise model energies of the dominant contacts were estimated to be in the range 20–70 kJ mol−1. It is interesting that the contribution of dispersive forces predominates over the electrostatic forces.