2,3-Diamino-pyridinium sorbate-sorbic acid (1/1).

In the title mol-ecular salt-adduct, C(5)H(8)N(3) (+)·C(6)H(7)O(2) (-)·C(6)H(8)O(2), the 2,3-diamino-pyridinium cation is essentially planar, with a maximum deviation of 0.013 (2) Å, and is protanated at its pyridine N atom. The sorbate anion and sorbic acid mol-ecules exist in extended conformations. In the crystal, the protonated N atom and one of the two amino-group H atoms are hydrogen bonded to the sorbate anion through a pair of N-H⋯O hydrogen bonds, forming an R(1) (2)(6) ring motif. The carboxyl groups of the sorbic acid mol-ecules and the carboxyl-ate groups of the sorbate anions are connected via O-H⋯O hydrogen bonds. Furthermore, the ion pairs and neutral mol-ecules are connected via inter-molecular N-H⋯O hydrogen bonds, forming sheets lying parallel to (100).

Bis(2,3-diamino-pyridinium) phthalate dihydrate.

The complete anion of the title hydrated mol-ecular salt, 2C(5)H(8)N(3) (+)·C(8)H(4)O(4) (-)·2H(2)O, is generated by a crystallographic twofold axis. In the crystal, the cations, anions and water mol-ecules are connected by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, forming a three-dimensional network. The crystal structure also features C-H⋯π inter-actions.

2,3-Diamino-pyridinium 3-chloro-benzo-ate-3-chloro-benzoic acid (1/1).

The asymmetric unit of the title compound, C(5)H(8)N(3) (+)·C(7)H(4)ClO(2) (-)·C(7)H(5)ClO(2), contains an ion pair and a 3-chloro-benzoic acid mol-ecule. In the cation, the pyridine N atom is protonated. In the crystal, the components are connected via N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, thereby forming sheets lying parallel to (100).

2,3-Diamino-pyridinium 2-hy-droxy-benzoate.

In the title mol-ecular salt, C(5)H(8)N(3) (+)·C(7)H(5)O(3) (-), the 2,3-diamino-pyridinium cation is essentially planar, with a maximum deviation of 0.006 (2) Å. In the crystal, adjacent cations and anions are linked by pairs of N-H⋯O hydrogen bonds, generating R(2) (2)(8) loops. These dimers are linked by further N-H⋯O hydrogen bonds and C-H⋯O inter-actions to form sheets lying parallel to (001). A typical intra-molecular O-H⋯O hydrogen bond is also observed in the salicylate (2-hy-droxy-benzoate) anion, which generates an S(6) ring. The crystal structure also features π-π stacking inter-actions between the pyridinium rings of the cations, with a centroid-centroid distance of 3.5896 (15) Å.

2,3-Diamino-pyridinium 3-carb-oxy-4-hy-droxy-benzene-sulfonate monohydrate.

In the title hydrated mol-ecular salt, C(5)H(8)N(3) (+)·C(7)H(5)O(6)S(-)·H(2)O, the ion pairs and water mol-ecules are connected by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, thereby forming a three-dimensional network. There is an intra-molecular O-H⋯O hydrogen bond in the 3-carb-oxy-4-hy-droxy-benzene-sulfonate anion, which generates an S(6) ring motif.

2,3-Diamino-pyridinium 4-carb-oxy-butano-ate.

In the title mol-ecular salt, C(5)H(8)N(3) (+)·C(5)H(7)O(4) (-), the 2,3-diamino-pyridine mol-ecule is protonated at the pyridine N atom. The cation is essentially planar, with a maximum deviation of 0.015 (2) Å, and the anion adopts an extended conformation. In the crystal, the hydrogen glutarate (4-carb-oxy-butano-ate) anions are self-assembled through O-H⋯O hydrogen bonds, forming chains. The cations are connected to the anion chains via N-H⋯O hydrogen bonds, forming a three-dimensional network. The crystal structure also features aromatic π-π inter-actions between the pyridinium cations, with a centroid-centroid distance of 3.4464 (10) Å.

Bis(2,1,3-benzoselenadiazole-κN)dibromidocopper(II).

In the title complex, [CuBr(2)(C(6)H(4)N(2)Se)(2)], the Cu(II) ion is tetra-coordinated by two bromide anions and two N atoms in a distorted square-planar geometry. The two essentially planar 2,1,3-benzoselenadiazole ligands [maximum deviations = 0.012 (2) and 0.030 (2) Å] are approximately coplanar [dihedral angle = 6.14 (6)°]. In the crystal, short inter-molecular Se⋯Br, Se⋯N and N⋯N inter-actions are observed. These short inter-actions and inter-molecular C-H⋯Br hydrogen bonds link the complex mol-ecules into two-dimensional arrays parallel to the ac plane.

(Z)-1,2-Dichloro-1,2-bis-(3-chloro-quinoxalin-2-yl)ethene.

The title compound, C(18)H(8)Cl(4)N(4), exists in a cis configuration with respect to the bridging C=C bond. The two essentially planar quinoxaline ring systems [maximum deviations = 0.012 (1) and 0.022 (1) Å] are inclined at an angle of 59.84 (3). In the crystal, adjacent mol-ecules are linked into chains propagating along [001] via inter-molecular C-H⋯N hydrogen bonds. Weak inter-molecular π-π [centroid-centroid distance = 3.6029 (7)°] and C-H⋯π inter-actions are also observed.

Adeninium perchlorate.

IN THE TITLE SALT (SYSTEMATIC NAME: 6-amino-9H-purin-1-ium perchlorate), C(5)H(6)N(5) (+)·ClO(4) (-), the adeninium cation is essentially planar, with a maximum deviation of 0.038 (1) Å. The whole of the perchlorate anion is disordered over two sets of sites with an occupancy ratio of 0.589 (13):0.411 (13). In the crystal, the adeninium cations are linked by pairs of N-H⋯N hydrogen bond into inversion dimers. The dimers and the anions are further inter-connected into a three-dimensional supra-molecular structure via inter-molecular N-H⋯O, C-H⋯O and C-H⋯N hydrogen bonds.

2-Bromo-3-phenyl-1-(3-phenyl-sydnon-4-yl)prop-2-en-1-one.

THE TITLE SYDNONE DERIVATIVE [SYSTEMATIC NAME: 2-bromo-1-(5-oxido-3-phenyl-1,2,3-oxadiazo-lium-4-yl)-3-phenyl-prop-2-en-1-one], C(17)H(11)BrN(2)O(3), exists in a Z configuration with respect to the acyclic C=C bond. An intra-molecular 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, inter-molecular C-H⋯O hydrogen bonds link mol-ecules into two-mol-ecule-thick arrays parallel to the bc plane. The crystal structure also features a short inter-molecular N⋯C contacts [3.030 (3) Å] as well as C-H⋯π and π-π inter-actions [centroid-centroid distances = 3.3798 (11) and 3.2403 (12) Å].

3-(2,3-Dimethyl-5-oxo-1-phenyl-2,5-di-hydro-1H-pyrazol-4-yl)sydnone.

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], C(13)H(12)N(4)O(3), the oxadiazole and pyrazole rings are essentially planar [maximum deviations = 0.006 (1) and 0.019 (1) Å, respectively] and are inclined at inter-planar angles of 37.84 (4) and 46.60 (4)°, respectively, with respect to the benzene ring. In the crystal, adjacent mol-ecules are inter-connected into a three-dimensional supra-molecular network via inter-molecular C-H⋯O hydrogen bonds. Weak inter-molecular π-π aromatic stacking inter-actions [centroid-centroid distance = 3.5251 (5) Å] further stabilize the crystal packing.

4-Formyl-3-p-tolyl-sydnone.

In the title compound, C(10)H(8)N(2)O(3), the oxadiazole ring is essentially planar, with a maximum deviation of 0.006 (1) Šfor the two-connected N atom. The mean planes through the aldehyde unit and the methyl-substituted phenyl ring make inter-planar angles of 13.60 (9) and 59.69 (4)°, respectively, with the oxadiazole ring. In the crystal structure, adjacent mol-ecules are inter-connected into a two-dimensional array parallel to (100) by inter-molecular C-H⋯O hydrogen bonds.

4-[3-(1-Naphthyl-oxymeth-yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazin-6-yl]-3-p-tolyl-sydnone.

In the title sydnone compound, C(24)H(18)N(6)O(3)S {systematic name: 4-[3-(1-naphthyl-oxymeth-yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazin-6-yl]-3-p-tolyl-4,5-dihydro-1,2,3-oxadiazol-3-ium-5-olate} an intra-molecular C-H⋯O hydrogen bond generates an S(6) ring motif. The 3,6-dihydro-1,3,4-thia-diazine 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 inter-planar angle of 44.11 (4)°. The naphthalene unit forms an inter-planar angle of 66.40 (4)° with the 1,2,4-triazole ring. In the crystal packing, pairs of inter-molecular C-H⋯O hydrogen bonds link adjacent mol-ecules into dimers incorporating R(2) (2)(12) ring motifs. Further stabilization is provided by weak C-H⋯π inter-actions.

3-Phenyl-4-{3-[(p-tol-yloxy)meth-yl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazin-6-yl}sydnone.

IN THE TITLE COMPOUND (SYSTEMATIC NAME: 3-phenyl-4-{3-[(p-tol-yloxy)meth-yl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazin-6-yl}-1,2,3-oxadiazol-3-ium-5-olate), C(20)H(16)N(6)O(3)S, an intra-molecular C-H⋯O hydrogen bond generates an S(6) ring motif. The 3,6-dihydro-1,3,4-thia-diazine ring adopts a twist-boat conformation. The 1,2,3-oxadiazole and 1,2,4-triazole rings are inclined to each other at an inter-planar angle of 44.13 (13)°. The phenyl ring makes an inter-planar angle of 67.40 (13)° with the attached 1,2,3-oxadiazole ring. In the crystal structure, adjacent mol-ecules are inter-connected into two-mol-ecule-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.

4-[3-(Phen-oxy-meth-yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazin-6-yl]-3-(p-tol-yl)sydnone.

In the title triazolothia-diazine derivative, C(20)H(16)N(6)O(3)S {systematic name: 3-(4-methyl-phen-yl)-4-[3-(phen-oxy-meth-yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazin-6-yl]-1,2,3-oxadiazol-3-ium-5-olate}, an S(6) ring motif is generated by an intra-molecular C-H⋯O hydrogen bond. The 3,6-dihydro-1,3,4-thia-diazine 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, inter-molecular C-H⋯O and C-H⋯N hydrogen bonds link neighbouring mol-ecules into two-mol-ecule-thick arrays parallel to the bc plane. A short S⋯O inter-action [2.9565 (19) Å] also occurs.

4-{3-[(2-Isopropyl-5-methyl-phen-oxy)meth-yl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazin-6-yl}-3-(p-tol-yl)sydnone.

In the title triazolothia-diazin compound, C(24)H(24)N(6)O(3)S (systematic name: 4-{3-[(2-isopropyl-5-methyl-phen-oxy)meth-yl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thia-diazin-6-yl}-3-(4-methyl-phen-yl)-1,2,3-oxadiazol-3-ium-5-olate), an intra-molecular 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 inter-planar angles of 73.1 (4) and 86.6 (8)°, respectively, with the attached phenyl ring. The 3,6-dihydro-1,3,4-thia-diazine ring adopts a twist-boat conformation. The inter-planar angle formed between 1,2,3-oxadiazole and 1,2,4-triazole rings is 18.80 (11)°. In the crystal, neighbouring mol-ecules are linked into sheets lying parallel to the bc plane by C-H⋯N hydrogen bonds. Weak inter-molecular π-π inter-actions [centroid-centroid distances = 3.2935 (11) and 3.5590 (12) Å] further stabilize the crystal structure.

2,5-Bis(4-meth-oxy-phen-yl)-1,3,4-oxadiazole.

In the title compound, C(16)H(14)N(2)O(3), 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 inter-molecular C⋯O inter-actions [2.9968 (15) Å] connect adjacent mol-ecules into chains propagating in [203]. The crystal structure is further stabilized by weak inter-molecular C-H⋯π inter-actions.

3-(p-Anis-yl)sydnone.

IN THE TITLE SYDNONE COMPOUND [SYSTEMATIC NAME: 3-(4-meth-oxy-phen-yl)-1,2,3-oxadiazol-3-ium-5-olate], C(9)H(8)N(2)O(3), 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 mol-ecules are inter-connected by inter-molecular C-H⋯O hydrogen bonds into sheets lying parallel to (100). Weak inter-molecular π-π inter-actions [centroid-centroid distance = 3.5812 (8) Å] further stabilize the crystal packing.

2-(tert-Butoxy-carbonyl-amino)-6-(1,3-dioxo-1H-2,3-dihydro-benzo[de]isoquinolin-2-yl)hexa-noic acid.

In the title naphthalimide derivative, C(23)H(26)N(2)O(6), the 1,8-naphthalimide system is essentially planar [maximum deviation = 0.0456 (16) Å]. A characteristic pattern of alternating long and short C-C bond lengths is observed in the 1,8-naphthalimide unit. The mean planes through the methyl carbamate and acetic acid groups form dihedral angles of 42.30 (9) and 61.59 (9)°, respectively, with the 1,8-naphthalimide plane. In the crystal structure, inter-molecular O-H⋯O and C-H⋯O hydrogen bonds link neighbouring mol-ecules, forming R(2) (2)(9) hydrogen-bond ring motifs. These rings are further inter-connected by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds into a three-dimensional supra-molecular network.

Guanidinium chloro-chromate.

In the title compound, guanidinium chloridotrioxidochrom-ate(VI), (CH(6)N(3))[CrClO(3)], both the cation and anion are generated by crystallographic mirror symmetry, with one O and one N atom and the Cr, Cl and C atoms lying on the mirror plane. The bond lengths in the guanidinium cation are inter-mediate between normal C-N and C=N bond lengths, indicating significant delocalization in this species. In the crystal structure, inter-molecular N-H⋯Cl inter-actions generate R(2) (1)(6) ring motifs. These ring motifs are further inter-connected by inter-molecular N-H⋯O hydrogen bonds into infinite chains along [010].