The title compound, C18H17N3O3S·C2H6OS, crystallizes in the monoclinic space group P21 /c. In the crystal, C 1 1(9) chains of C-H⋯O inter-actions are formed, propogating in the c-axis direction. The N-H hydrogen atom forms a strong hydrogen bond with the oxygen atom of a DMSO solvate mol-ecule.

The crystal structures and Hirshfeld surface analyses of three salts of 1-(4-nitrophenyl)piperazine with 2-chlorobenzoic acid, 2-bromobenzoic acid and 2-iodobenzoic acid are reported. The chlorobenzoate salt, C10H14N3O2 +·C7H4ClO2 −, contains whole-ion-disordered cations and anions, which were modeled with two equivalent conformations with occupancies of 0.745 (10)/0.255 (10) and 0.563 (13)/0.437 (13), respectively. The bromobenzoate and iodobenzoate derivatives are isomorphous and crystallize as hemihydrates, viz. C10H14N3O2 +·C7H4BrO2 −·0.5H2O and C10H14N3O2 +·C7H4IO2 −·0.5H2O, respectively [the water molecule is disordered over two locations with occupancies of 0.276 (3)/0.223 (3) for the iodobenzoate derivative]. In the extended structures, all three salts feature an R 4 4(12) loop of two anions and two cations linked by N—H...O hydrogen bonds.

The structures and Hirshfeld surface analysis of three salts of 1-(4-nitrophenyl)piperazine are discussed. In 4-(4-nitrophenyl)piperazin-1-ium salicylate (C10H14N3O2+·C7H5O3−), there are strong hydrogen bonds between cation and anion and the 4-nitrophenyl substituent occupies an equatorial position in the piperazinium ring. The cation and anion are linked together by supramolecular interactions [graph-set notation of hydrogen bonding C_{2}^{2}(6) propagating in the a-axis direction]. Additionally, there is π–π stacking involving the salicylate anion and the piperazinium cation in adjacent asymmetric units as well as a C—H...π interaction between a hydrogen atom on the piperazine ring and the phenyl ring within the salicyclate anion. In bis[4-(4-nitrophenyl)piperazin-1-ium] bis(4-fluorobenzoate) trihydrate (2C10H14N3O2+·2C7H4FO2−·3H2O), there are two cations, two anions, and three water molecules of solvation in the asymmetric unit, all linked by hydrogen bonds [graph-set notation of hydrogen bonding R22(20) between adjacent cations and R33(9) between a cation and its adjacent anion]. In the anion, the 4-nitrophenyl ring occupies an axial substitution position in the piperazinium ring, which is relatively rare. Within the asymmetric unit, the phenyl groups in the cations show an offset π–π interaction. Additionally, there is a C—H...π interaction between a hydrogen atom on the phenyl ring within a cation and the phenyl ring within an anion. In 4-(4-nitrophenyl)piperazin-1-ium 3,5-dinitrobenzoate (C10H14N3O2+·C7H4N2O6−), there is a strong N—H...O hydrogen bond linking the cation and anion and the 4-nitrophenyl ring occupies an axial substitution position in the piperazinium ring, as seen in the previous structure. In the crystal, the cation and the anion form a complex three-dimensional hydrogen-bonded array involving R22(8), R44(12) and R44(20) rings propogating in the a-axis direction. The nitrophenyl group is disordered with occupancies of 0.806 (10) and 0.194 (10).

In the title compound, C28H22FN3OS, four rings are almost coplanar, with the fluorophenyl ring substantially twisted. In the extended structure, aromatic π-π stacking inter-actions between the pyrazole ring and the tolyl ring link the mol-ecules into centrosymmetric dimers.

In the title compound, C 18 H 16 N 2 O 2 , the phenyl and pyrazole rings subtend a dihedral angle of 22.68 (8)°. The packing of the title compound features aromatic π–π stacking and weak C—H...π interactions.

The title compound, C29H25N3O3S, crystallizes in the monoclinic space group P21/n. The molecule contains a central four-ring system in which all of the rings are almost coplanar. Both the 4-methoxyphenyl ring and the prop-2-ynyloxy substituent are disordered over two equivalent conformations with occupancy ratios of 0.903 (2):0.097 (2) and 0.776 (5):0.224 (5), respectively. In the crystal, π–π interactions [centroid–centroid distance = 3.7327 (11) Å] between the dihydropyrazole ring and the 4-methoxyphenyl ring link the molecules into centrosymmetric dimers. In addition, there are weak C—H...S, C—H...N and C—H...O interactions, which link the molecules into a complex three-dimensional array.

The title compound, C29H25N3O3S, crystallizes in the monoclinic space group P21/n. The mol­ecule contains a central four-ring system in which all of the rings are almost coplanar. Both the 4-meth­oxy­phenyl ring and the prop-2-yn­yloxy substituent are disordered over two equivalent conformations with occupancy ratios of 0.903 (2):0.097 (2) and 0.776 (5):0.224 (5), respectively. In the crystal, π–π inter­actions [centroid–centroid distance = 3.7327 (11) Å] between the di­hydro­pyrazole ring and the 4-meth­oxy­phenyl ring link the mol­ecules into centrosymmetric dimers. In addition, there are weak C—H⋯S, C—H⋯N and C—H⋯O inter­actions, which link the mol­ecules into a complex three-dimensional array.Unlabelled Image

In the title compound, C28H22FN3OS, four rings are almost coplanar, with the fluorophenyl ring substantially twisted. In the extended structure, aromatic π–π stacking inter­actions between the pyrazole ring and the tolyl ring link the mol­ecules into centrosymmetric dimers.Unlabelled Image

The structure of the title compound, C18H13NO4, shows that the whole molecule is almost planar but with a dihedral angle between the two phenyl rings of 19.22 (5)°. The molecules are linked by C—H...O interactions, forming sheets in the (21\overline{1}) plane.