Bis(2-amino-4-methyl­pyrimidin-1-ium) hexa­aqua­cobalt(II) disulfate dihydrate

In the title hydrated mixed-cation salt, (C₅H₈N₃)₂[Co(H₂O)₆](SO₄)₂·2H₂O, the complete octa­hedral hexa­aqua complex cation is generated by crystallographic inversion symmetry. In the crystal, the components are linked by O—H...O and N—H...O hydrogen bonds, the latter, involving pyrimidinium cations and sulfate anions, generating R₂²(8) loops. These, together with π–π inter­actions between centrosymmetrically related pyrimidinium cations [centroid–centroid separation = 3.5460 (8) Å], lead to the formation of a three-dimensional network.

4-Cyano-1-methyl­pyridinium nitrate

The title mol­ecular salt, C₇H₇N₂⁺·NO₃⁻, displays an inter­penetrating sheet structure parallel to a with each sheet containing nearly coplanar cations and anions, each ion being bis­ected by a crystallographic mirror plane. C—H...O hydrogen bonds involving both ring and methyl H atoms in addition to cation–cation C—H...N hydrogen bonds (ring H to cyano N) serve to link the sheets together. In each set of parallel layers, the cations and anions stack with short distances of 3.094 (2) (between aligned nitrate N and pyridine N atoms) and 3.057 (2) Å (between a nitrate O atom and the ring centroid). This motif is strikingly similar to the one that features in the isomeric salt 2-cyano-1-methyl­pyridinium nitrate.

Ethyl 2-(5-meth­oxy-2-methyl-1H-indol-3-yl)acetate

In the title compound, C₁₄H₁₇NO₃, the nine-membered 1H-indole ring system is essentially planar [maximum deviation = 0.019 (1) Å]. In the crystal, mol­ecules are linked via N—H...O hydrogen bonds, forming chains along [001]. These chains are linked via C—H...O hydrogen bonds and C—H...π inter­actions, forming a two-dimensional network lying parallel to the ac plane.

4-Phenyl-1,2,4-tri­aza­spiro­[4.5]dec-1-ene-3-thione

In the title compound, C₁₃H₁₅N₃S, the 4,5-di­hydro-3H-1,2,4-triazole ring is nearly planar [maximum deviation = 0.020 (1) Å], while the cyclo­hexane ring adopts a chair conformation. The dihedral angle between the 4,5-di­hydro-3H-1,2,4-triazole ring and the phenyl ring is 74.68 (7)°. No specific inter­molecular inter­actions are discerned in the crystal packing.

2-Cyano-1-methyl­pyridinium iodide

The cation in the title compound, C₇H₇N₂⁺·I⁻, is planar (r.m.s. deviation for the nine fitted non-H atoms = 0.040 Å). The crystal packing is best described as undulating layers of cations and anions associated via C—H...I inter­actions.

2-Cyano­anilinium iodide

The solid-state structure of the title salt, C₇H₇N₂^+.I⁻, consists of cation–anion sheets lying parallel to (110), with the components linked by N—H...I hydrogen bonds.

(1Z,2E)-1-(3,4-Diphenyl-2,3-di­hydro-1,3-thia­zol-2-yl­idene)-2-(1-p-tolyl­ethyl­idene)hydrazine

In the title compound, C₂₄H₂₁N₃S, the thia­zole ring makes dihedral angles of 52.03 (6), 62.63 (6) and 12.35 (6)°, respectively, with the two phenyl rings and the benzene ring. In the crystal, weak C—H...π inter­actions occur between inversion-related mol­ecules.

Methyl (2Z)-((2Z)-2-{(2E)-[1-(4-methyl­phen­yl)ethyl­idene]hydrazinyl­idene}-4-oxo-3-phenyl-1,3-thia­zolidin-5-yl­idene)ethano­ate

The asymmetric unit of the title compound, C₂₁H₁₉N₃O₃S, contains two independent mol­ecules. In one mol­ecule, the 1,3-thia­zolidine ring forms dihedral angles of 86.19 (8) and 8.37 (8)° with the phenyl and benzene rings, respectively. The corresponding dihedral angles in the other mol­ecule are 69.60 (7) and 14.08 (7)°. The dihedral angle between the phenyl and benzene rings is 84.70 (8)° in one mol­ecule and 69.62 (8)° in the other. In the crystal, mol­ecules pack in layers approximately parallel to (10-2). There are weak C—H...O hydrogen bonds within these layers. Further weak C—H...O hydrogen bonding occurs between the layers to form a three-dimensional network. A weak C—H...π inter­action is also observed.

2-(5-Meth­oxy-2-methyl-1H-indol-3-yl)-N′-[(1E,2E)-3-phenyl­prop-2-en-1-yl­idene]acetohydrazide

The title compound, C₂₁H₂₁N₃O₂, adopts a J-shaped conformation which appears to be at least partially directed by a weak intra­molecular C—H...N hydrogen bond. In the crystal, mol­ecules are linked by N—H...O hydrogen bonds into R₂²(8) and R₂²(14) cyclic dimers, which form a chain running parallel to the b axis.

Methyl 2-((2Z,5Z)-2-{(E)-2-[1-(4-hy­droxy­phen­yl)ethyl­idene]hydrazin-1-yl­idene}-4-oxo-3-phenyl-1,3-thia­zolidin-5-yl­idene)acetate

In the title compound, C₂₀H₁₇N₃O₄S, all non-H atoms, except those of the phenyl ring, are approximately coplanar [maximum deviation = 0.2214 (1) Å], and the dihedral angle between their best plane and the benzene ring is 53.13 (1)°. A short intra­molecular O...S contact of 2.838 (1) Å is formed between the ester carbonyl O atom and the S atom of the thia­zolidine ring. In the crystal, mol­ecules associated via O—H...O, C—H...O and C—H...S hydrogen bonds form layers parallel to (010), with only C—H...O-type short contacts between the mol­ecules in adjacent layers.

(2E)-4-(4-Bromo­phen­yl)-2-{(2Z)-[1-(4-methyl­phen­yl)ethyl­idene]hydrazinyl­idene}-3-phenyl-2,3-di­hydro-1,3-thia­zole

In the title compound, C₂₄H₂₀BrN₃S, the di­hydro­thia­zole ring is approximately planar, with a maximum deviation of 0.008 (2) Å, and is twisted with respect to the 4-bromo­phenyl ring, the phenyl ring and methyl­phenyl ring, making dihedral angles of 47.96 (8), 59.52 (9) and 16.96 (9)°, respectively. In the crystal, weak C—H...π inter­actions link inversion-related mol­ecules into supra­molecular dimers.

N′-[(E)-Benzyl­idene]-2-(6-meth­oxy­naphthalen-2-yl)propano­hydrazide

The title mol­ecule, C₂₁H₂₀N₂O₂, exists in the solid state in the `extended' form. The crystal packing consists of ribbons of mol­ecules extending parallel to c and associated via N—H...O and weak C—H...O hydrogen bonds. C—H...π inter­actions are also present.

N′-[(E)-4-Meth­oxy­benzyl­idene]-2-(5-meth­oxy-2-methyl-1H-indol-3-yl)acetohydrazide

The conformation adopted by the title compound, C₂₀H₂₁N₃O₃, in the crystal is `J'-shaped and appears to be at least partially directed by a weak intra­molecular C—H...N hydrogen bond. In the crystal, mol­ecules are linked by N—H...O hydrogen bonds, forming dimers with R₂²(8) motifs. Furthermore, these dimers connect to each other via C—H...O and N—H...O hydrogen bonds to form a three-dimensional network.

Dimethyl (2Z)-2-[4-((1Z)-1-{2-[(2Z,5Z)-5-(2-meth­oxy-2-oxo­ethyl­idene)-4-oxo-3-phenyl-1,3-thia­zolidin-2-yl­idene]hydra­zin-1-yl­idene}eth­yl)anilino]but-2-ene­dio­ate

The mol­ecule of the title compound, C₂₆H₂₄N₄O₇S, adopts a trans conformation about the central N—N bond, presumably to minimize steric between the substituents on these two atoms. An intra­molecular N—H...O hydrogen bond occurs. The phenyl ring is disordered over two sets of sites, with an occupancy ratio of 0.624 (8):0.376 (8). The azolidine ring is essentially planar [maximum deviation = 0.008 (5) Å] and makes a dihedral angle of 4.3 (2)° with the benzene ring and dihedral angles of 74.1 (3) and 69.1 (5)°, respectively, with the mean planes of the major and minor components of the disordered phenyl ring. The packing in the crystal is aided by the formation of several weak C—H...O and C—H...N inter­actions.

2,2′-[(1,3,4-Thia­diazole-2,5-di­yl)bis­(sulfanedi­yl)]diaceto­nitrile

In the title compound, C₆H₄N₄S₃, the 1,3,4-thia­diazole ring is essentially planar, with an r.m.s. deviation of 0.001 Å. The two N—C—S—C torsion angles in the mol­ecule are −23.41 (15) and 0.62 (14)°. One aceto­nitrile group is above the plane of the 1,3,4-thia­diazole ring and the other is below it, indicating syn and anti orientations. In the crystal, C—H...N hydrogen bonds link the molecules into ribbons along [010].