In the title sydnone compound [systematic name: 3-(4-meth­oxy­phen­yl)-1,2,3-oxadiazol-3-ium-5-olate], C9H8N2O3, the essentially planar oxadiazole ring [maximum deviation = 0.005 (1) Å] is inclined at a dihedral angle of 30.32 (8)° with respect to the benzene ring. In the crystal, adjacent mol­ecules are inter­connected by inter­molecular C—H⋯O hydrogen bonds into sheets lying parallel to (100). Weak inter­molecular π–π inter­actions [centroid–centroid distance = 3.5812 (8) Å] further stabilize the crystal packing.

In the title compound, C14H8F2N2O, the amide plane is inclined at dihedral angles of 28.12 (12) and 32.89 (12)° with respect to the two benzene rings; the dihedral angle between the two rings is 5.58 (5)°. In the crystal, inter­molecular N—H⋯O and C—H⋯F hydrogen bonds link adjacent mol­ecules into a double-chain structure along the b axis.

In the title compound, C16H14N2O3, the essentially planar 1,3,4-oxadiazole ring [maximum deviation = 0.0021 (11) Å] is inclined at dihedral angles of 8.06 (6) and 11.21 (6)° with respect to the two benzene rings; the dihedral angle between the latter rings is 11.66 (5)°. In the crystal, short inter­molecular C⋯O inter­actions [2.9968 (15) Å] connect adjacent mol­ecules into chains propagating in [203]. The crystal structure is further stabilized by weak inter­molecular C—H⋯π inter­actions.

In the title triazolothia­diazin compound, C24H24N6O3S (systematic name: 4-{3-[(2-isopropyl-5-methyl­phen­oxy)meth­yl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl}-3-(4-methyl­phen­yl)-1,2,3-oxadiazol-3-ium-5-olate), an intra­molecular C—H⋯O hydrogen bond generates an S(6) ring motif. The two terminal methyl groups of the isopropyl unit are disordered over two sets of positions in a 0.715 (4):0.285 (4) ratio. The mean planes formed through the major and minor disordered isopropyl units are inclined at inter­planar angles of 73.1 (4) and 86.6 (8)°, respectively, with the attached phenyl ring. The 3,6-dihydro-1,3,4-thia­diazine ring adopts a twist-boat conformation. The inter­planar angle formed between 1,2,3-oxadiazole and 1,2,4-triazole rings is 18.80 (11)°. In the crystal, neighbouring mol­ecules are linked into sheets lying parallel to the bc plane by C—H⋯N hydrogen bonds. Weak inter­molecular π–π inter­actions [centroid–centroid distances = 3.2935 (11) and 3.5590 (12) Å] further stabilize the crystal structure.

In the title triazolothia­diazine derivative, C20H16N6O3S {systematic name: 3-(4-methyl­phen­yl)-4-[3-(phen­oxy­meth­yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl]-1,2,3-oxadiazol-3-ium-5-olate}, an S(6) ring motif is generated by an intra­molecular C—H⋯O hydrogen bond. The 3,6-dihydro-1,3,4-thia­diazine ring adopts a twist-boat conformation. The dihedral angle between the 1,2,3-oxadiazole and 1,2,4-triazole rings is 46.45 (14)°. The 1,2,3-oxadiazole ring is inclined at dihedral angle of 59.49 (13)° with respect to the benzene ring attached to it. In the crystal structure, inter­molecular C—H⋯O and C—H⋯N hydrogen bonds link neighbouring mol­ecules into two-mol­ecule-thick arrays parallel to the bc plane. A short S⋯O inter­action [2.9565 (19) Å] also occurs.

In the title compound (systematic name: 3-phenyl-4-{3-[(p-tol­yloxy)meth­yl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl}-1,2,3-oxadiazol-3-ium-5-olate), C20H16N6O3S, an intra­molecular C—H⋯O hydrogen bond generates an S(6) ring motif. The 3,6-dihydro-1,3,4-thia­diazine ring adopts a twist-boat conformation. The 1,2,3-oxadiazole and 1,2,4-triazole rings are inclined to each other at an inter­planar angle of 44.13 (13)°. The phenyl ring makes an inter­planar angle of 67.40 (13)° with the attached 1,2,3-oxadiazole ring. In the crystal structure, adjacent mol­ecules are inter­connected into two-mol­ecule-thick arrays parallel to (100) via C—H⋯O and C—H⋯N hydrogen bonds. A short S⋯O contact [2.9512 (18) Å] is observed.

In the title compound, C16H13N3OS, the thio­morpholine ring exists in a screw boat conformation. The angle between the benzimidazole ring system and the benzene ring fused to the thia­zine ring is 67.22 (6)°. In the crystal, mol­ecules form infinite chains along the a axis via inter­molecular N—H⋯N inter­actions. C—H⋯π inter­actions also contribute to the stability of the crystal structure.

In the title sydnone compound, C24H18N6O3S {systematic name: 4-[3-(1-naphthyl­oxymeth­yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazin-6-yl]-3-p-tolyl-4,5-dihydro-1,2,3-oxadiazol-3-ium-5-olate} an intra­molecular C—H⋯O hydrogen bond generates an S(6) ring motif. The 3,6-dihydro-1,3,4-thia­diazine ring adopts a twist-boat conformation. The essentially planar 1,2,3-oxadiazole and 1,2,4-triazole rings [maximum deviations of 0.006 (1) and 0.008 (1) Å, respectively] are inclined to one another at inter­planar angle of 44.11 (4)°. The naphthalene unit forms an inter­planar angle of 66.40 (4)° with the 1,2,4-triazole ring. In the crystal packing, pairs of inter­molecular C—H⋯O hydrogen bonds link adjacent mol­ecules into dimers incorporating R 2 2(12) ring motifs. Further stabilization is provided by weak C—H⋯π inter­actions.

In the title sydnone compound [systematic name: 3-(2,3-dimethyl-5-oxo-1-phenyl-2,5-dihydro-1H-pyrazol-4-yl)-1,2,3-oxadiazol-3-ium-5-olate], C13H12N4O3, the oxadiazole and pyrazole rings are essentially planar [maximum deviations = 0.006 (1) and 0.019 (1) Å, respectively] and are inclined at inter­planar angles of 37.84 (4) and 46.60 (4)°, respectively, with respect to the benzene ring. In the crystal, adjacent mol­ecules are inter­connected into a three-dimensional supra­molecular network via inter­molecular C—H⋯O hydrogen bonds. Weak inter­molecular π–π aromatic stacking inter­actions [centroid–centroid distance = 3.5251 (5) Å] further stabilize the crystal packing.

In the title compound, C10H8N2O3, the oxadiazole ring is essentially planar, with a maximum deviation of 0.006 (1) Å for the two-connected N atom. The mean planes through the aldehyde unit and the methyl-substituted phenyl ring make inter­planar angles of 13.60 (9) and 59.69 (4)°, respectively, with the oxadiazole ring. In the crystal structure, adjacent mol­ecules are inter­connected into a two-dimensional array parallel to (100) by inter­molecular C—H⋯O hydrogen bonds.

In the title pyrazole compound, C20H13N3O4, an intra­molecular C—H⋯O hydrogen bond generates a seven-membered ring, producing an S(7) ring motif. The essentially planar furan and pyrazole rings [maximum deviations of 0.002 (1) and 0.007 (1) Å, respectively] are coplanar with each other, forming a dihedral angle of 3.06 (10)°. The pyrazole ring forms dihedral angles of 8.51 (9) and 56.81 (9)° with the two benzene rings. The nitro group is coplanar with the attached furan ring, as indicated by the dihedral angle of 2.5 (3)°. In the crystal packing, inter­molecular C—H⋯O hydrogen bonds link adjacent mol­ecules into two-mol­ecule-wide chains along the a axis. The crystal packing is further stabilized by weak inter­molecular C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.4441 (10) Å].

The title sydnone derivative [systematic name: 2-bromo-1-(5-oxido-3-phenyl-1,2,3-oxadiazo­lium-4-yl)-3-phenyl­prop-2-en-1-one], C17H11BrN2O3, exists in a Z configuration with respect to the acyclic C=C bond. An intra­molecular C—H⋯Br hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The 1,2,3-oxadiazole ring in the sydnone unit is essentially planar [maximum deviation = 0.011 (2) Å] and forms dihedral angles of 55.39 (13) and 57.12 (12)° with the two benzene rings. In the crystal structure, inter­molecular C—H⋯O hydrogen bonds link mol­ecules into two-mol­ecule-thick arrays parallel to the bc plane. The crystal structure also features a short inter­molecular N⋯C contacts [3.030 (3) Å] as well as C—H⋯π and π–π inter­actions [centroid–centroid distances = 3.3798 (11) and 3.2403 (12) Å].

In the title compound, C26H32FN5OS·0.5CH4O, the methyl group of the methanol solvent mol­ecule is disordered over two sites with equal occupancies and the solvent is further disordered about a crystallographic twofold rotation axis. The organic mol­ecule exists in a trans configuration with respect to the acyclic C=N bond. An intra­molecular C—H⋯S hydrogen bond generates an S(6) ring motif. The morpholine ring adopts a chair conformation. The essentially planar 1,2,4-triazole ring [maximum deviation = 0.013 (2) Å] forms dihedral angles of 11.21 (10) and 67.53 (11)°, respectively, with the fluoro­phenyl unit and the isobutyl-substituted benzene ring. The crystal structure is stabilized by a weak inter­molecular C—H⋯π inter­action.

In the title compound, C21H14ClN3O5, an intra­molecular C—H⋯O hydrogen bond generates an S(7) ring motif and the furan and pyrazole rings are almost coplanar, making a dihedral angle of 1.98 (5)°. The pyrazole ring is inclined at dihedral angles of 47.59 (4) and 7.27 (4)° to the chloro­phenyl and methoxy­phenyl groups, respectively. The nitro group is almost coplanar to its attached furan ring [dihedral angle = 2.03 (12)°]. In the crystal, inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network. The crystal structure also features short inter­molecular O⋯N [2.8546 (12) Å] and Cl⋯O [3.0844 (9) Å] contacts as well as aromatic π–π stacking inter­actions [centroid–centroid distance = 3.4367 (6) Å].

Structural studies of the title compound [systematic name: 2,2′-(disulfanedi­yl)dianiline], C12H12N2S2, were previously performed at room temperature [Gomes de Mesquita (1967 ▶). Acta Cryst. 23, 671; Lee & Bryant (1970 ▶). Acta Cryst. B26, 1729; Ribar et al. (1975 ▶). Bull. Yugoslav. Crystallogr. Centre, A10, 68]. The results of the current redetermination allow a clarification of the nature of the intra- and inter­molecular N—H⋯S hydrogen bonding described in the literature for this compound. On cooling to 100 K, the unit cell contracts most in the c axis, and it changes rather less in the directions involving the strongly hydrogen-bonded chains, which are the a and b axes. In the crystal structure, N—H⋯N hydrogen bonds link neighbouring mol­ecules into two-dimensional frameworks parallel to the ab plane. An additional inter­molecular N—H⋯S hydrogen bond has also been established, based on freely refined H-atom positions. Inter­molecular C—H⋯π inter­actions further stabilize the crystal structure.

The title 1,2,4-triazole compound, C34H34FN5S, exists in a trans configuration with respect to the acyclic C=N bond. An intra­molecular C—H⋯S contact generates a six-membered ring, producing an S(6) ring motif. The essentially planar 1,2,4-triazole ring [maximum deviation 0.008 (1) Å] is inclined at 21.43 (5) and 83.03 (6)°, respectively, with respect to the flurophenyl unit and the isobutyl-substituted benzene ring. The diphenyl­amino unit is not planar, as indicated by the dihedral angle between two phenyl rings of 76.95 (6)°. The crystal structure is stabilized by C—H⋯π and π–π [centroid–centroid distance = 3.6169 (6) Å] inter­actions; mol­ecules are stacked along the b axis.

The asymmetric unit of the title compound, C22H26N4O2S, contains two crystallographically independent mol­ecules (A and B). The isobutyl unit of mol­ecule B is disordered over two orientations with refined occupancies of 0.785 (6) and 0.215 (6). In each mol­ecule, intra­molecular C—H⋯S hydrogen bonds generate S(6) ring motifs. The essentially planar 1,2,4-triazole rings [r.m.s. deviations of 0.004 (2) and 0.011 (2) Å, in A and B respectively] form dihedral angles of 85.86 (12), 8.38 (10)°, respectively, with the isobutyl-substituted phenyl ring and the 2-methoxy­phenol substituent in mol­ecule A [89.26 (13) and 2.46 (10)°, respectively, in B]. In the crystal structure, inter­molecular N—H⋯N and N—H⋯S hydrogen bonds link neighbouring mol­ecules, generating R 2 2(7) ring motifs. These molecules are further inter­connected into extended chains along [20] by inter­molecular O—H⋯O hydrogen bonds. The crystal structure is further stabilized by π–π [centroid-centroid distance = 3.6299 (13) Å] and C—H⋯π inter­actions. A short O⋯O contact of 2.781 (2) Å is also observed.

The title hydrazide compound, C20H24N2O2, exists in a trans configuration with respect to the acyclic C=N bond and an intra­molecular O—H⋯N hydrogen bond generates an S(6) ring motif. The mean plane through the formohydrazide unit is essentially planar [maximum deviation = 0.025 (2) Å], and forms dihedral angles of 24.45 (16) and 87.14 (16)° with the two benzene rings. In the crystal structure, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds link neighbouring mol­ecules into extended chains along the c axis, which incorporate R 2 2(16) ring motifs. An inter­molecular C—H⋯π inter­action is also observed.

The title 1,2,4-triazole compound, C13H11N5OS·C3H7NO, crystallizes as a 1:1 dimethyl­formamide (DMF) solvate. The main mol­ecule exists in a trans configuration with respect to the acyclic C=N bond. An intra­molecular C—H⋯S hydrogen bond generates an S(6) ring motif. In the synthesis, a proton is transferred from the O atom of a hydr­oxy group to the quinoline group N atom. The essentially planar triazole ring and quinoline ring system [maximum deviations of 0.001 (2) and 0.013 (2) Å, respectively] form a dihedral angle of 5.86 (9)°. In the crystal structure, mol­ecules of (E)-4-[(2-hydroxy-3-­quinolyl)methyl­eneamino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione are linked into R 2 2(8) centrosymmteric dimers via N—H⋯O hydrogen bonds. These dimers are further linked into an extended three-dimensional structure by the DMF solvent mol­ecules via inter­molecular N—H⋯O and C—H⋯O hydrogen bonds. The crystal structure is consolidated by two different inter­molecular π–π inter­actions [centroid–centroid distances = 3.6593 (12) and 3.6892 (12) Å].

In the title pyrazoline compound, C19H14BrN5O2, the essentially planar pyrazoline and pyrimidine rings [maximum deviations = 0.013 (1) and 0.009 (1) Å, respectively] are inclined slightly to one another, making a dihedral angle of 10.81 (10)°. The nitro­benzene unit is almost perpendicular to the attached pyrazoline ring, as indicated by the dihedral angle of 84.61 (8)°. In the crystal structure, inter­molecular C—H⋯N contacts link the mol­ecules into dimers in an anti­parallel manner. These dimers are further linked into one-dimensional chains along the b axis via C—H⋯O contacts. The crystal structure is consolidated by three different inter­molecular π–π inter­actions [range of centroid–centroid distances = 3.5160 (11)–3.6912 (11) Å].

In the title pyrazole compound, C22H17N3O4, an intra­molecular C—H⋯O contact generates a seven-membered ring, producing an S(7) ring motif. The furan and pyrazole rings are essentially planar [maximum deviations = 0.004 (1) and 0.004 (2) Å, respectively] and are almost coplanar, making a dihedral angle of 3.75 (10)°. One of the methyl­phenyl groups is inclined to the pyrazole ring, as indicated by the dihedral angle of 48.41 (9)°. In the crystal structure, mol­ecules are linked into chains along [10] by C—H⋯O contacts. The crystal structure is further stabilized by π–π inter­actions [centroid–centroid distance = 3.4437 (10) Å].

In the title pyrazole compound, C21H15N3O4, an intra­molecular C—H⋯O hydrogen bond generates an S(7) ring motif. The essentially planar furan and pyrazole rings [maximum atomic deviations of 0.011 (2) and 0.006 (2) Å, respectively] make a dihedral angle of 9.21 (11)°. The nitro group is approximately coplanar with the attached furan ring, as indicated by the dihedral angle of 4.5 (2)°. In the crystal structure, inter­molecular C—H⋯O inter­actions form bifurcated hydrogen bonds, generating R 1 2(7) ring motifs. These hydrogen bonds link the mol­ecules into infinite chains along the a axis. The crystal structure is further stabilized by weak inter­molecular π–π inter­actions [centroid–centroid distance = 3.4118 (10) Å].

The asymmetric unit of the title compound, C5H4Cl2N2O, contains one half-mol­ecule: all the non-H atoms lie on a crystallographic mirror plane. In the crystal structure, mol­ecules are linked into chains along the c axis by weak inter­molecular C—H⋯O hydrogen bonds.

In the title compound, C10H9NO3S·H2O, the thio­morpholine ring exists in a conformation inter­mediate between twist-boat and half-chair. An inter­molecular O—H⋯O hydrogen bond links the acid and water mol­ecules together. In the crystal packing, inter­molecular O—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network.

In the title compound, C21H23FN4S, the benzene rings of the isobutyl­phenyl and fluoro­benzene units form dihedral angles of 75.89 (7) and 13.26 (7)°, respectively, with the triazole ring. An intra­molecular C—H⋯S hydrogen-bonding contact generates an S(6) ring motif. In the crystal packing, pairs of N—H⋯S hydrogen bonds link neighbouring mol­ecules into inversion dimers, forming R 2 2(8) ring motifs. The crystal structure is further stabilized by C—H⋯π inter­actions.