Anilinium-3-carboxyl­ate 3-carb­oxy­anilinium nitrate

The title compound, C₇H₈NO₂⁺·NO₃⁻·C₇H₇NO₂, exists in the form of a protonated dimer of two anilinium-3-carboxyl­ate mol­ecules related by an inversion center, and a nitrate anion located on a twofold rotation axis. The bridging H atom occupies, with equal probability, the two sites associated with the carboxyl atoms. In addition to the strong O—H...O hydrogen bond, in the crystal, the various units are linked via N—H...O and C—H...O hydrogen bonds forming a three-dimensional structure.

6-Bromo-1-methyl-4-[2-(1-phenyl­ethyl­idene)hydrazinyl­idene]-3,4-dihydro-1H-2λ⁶,1-benzothia­zine-2,2-dione

In the title compound, C₁₇H₁₆BrN₃O₂S, the dihedral angle between the aromatic rings is 1.24 (15)° and the C=N—N=C torsion angle is 167.7 (3)°. The conformation of the thia­zine ring is an envelope, with the S atom displaced by 0.805 (3) Å from the mean plane of the other five atoms (r.m.s. deviation = 0.027 Å). In the crystal, C—H...O inter­actions link the mol­ecules into C(10) [010] chains. A weak C—H...π inter­action is also observed.

3-Chloro-1-methyl-4-[2-(3-phenyl­allyl­idene)hydrazinyl­idene]-3,4-dihydro-1H-2λ⁶,1-benzothia­zine-2,2-dione

In the title compound, C₁₈H₁₆ClN₃O₂S, the dihedral angle between the aromatic rings is 4.81 (2)° and the alkyl chain takes on an extended conformation [N—C—C—C = 179.2 (4)°]. The conformation of the thia­zine ring is an envelope, with the S atom displaced by −0.805 (3) Å from the mean plane of the other five atoms (r.m.s. deviation = 0.046 Å). The Cl atom is an axial conformation and is displaced by 1.761 (4) Å from the thia­zine ring plane. In the crystal, inversion dimers linked by pairs of C—H...O inter­actions generate R₂²(20) loops and further C—H...O hydrogen bonds link the dimers into (001) sheets. Weak aromatic π–π stacking inter­actions [centroid–centroid separations = 3.870 (3) and 3.883 (3) Å] are also observed.

1-Ethyl-4-{2-[1-(4-methyl­phen­yl)ethyl­idene]hydrazinyl­idene}-3,4-dihydro-1H-2λ⁶,1-benzothia­zine-2,2-dione

In the title compound, C₁₉H₂₁N₃O₂S, the dihedral angle between the aromatic rings is 6.7 (2)° and the C=N—N=C torsion angle is 178.0 (2)°. The conformation of the thia­zine ring is an envelope, with the S atom displaced by 0.802 (2) Å from the mean plane of the other five atoms (r.m.s. deviation = 0.022 Å). In the crystal, mol­ecules are linked by C—H...O inter­actions, generating C(5) chains propagating in [010]. A weak C—H...π inter­action is also observed.

Methyl 2,4-dihy­droxy-5-(4-nitro­benzamido)­benzoate

In the title compound, C₁₅H₁₂N₂O₇, the dihedral angle between the aromatic rings is 4.58 (13)° and the nitro group is rotated from its attached ring by 18.07 (17)°. Intra­molecular N—H...O and O—H...O hydrogen bonds generate S(5) and S(6) rings, respectively. In the crystal, mol­ecules are linked by O—H...O hydrogen bonds, generating [001] C(7) chains. The chains are linked by C—H...O inter­actions, forming a three-dimensional network, which incorporates R₂²(7) and R₂²(10) loops.

Ethyl N-(2-benzoyl-3-oxo-3-phenyl­propano­yl)carbamate

In the title compound, C₁₉H₁₇NO₅, the dihedral angle between the phenyl groups is 79.55 (15)°. The terminal eth­oxy group is disordered over two orientations in a 0.873 (6):0.127 (6) ratio. In the crystal, mol­ecules are linked by N—H...O and C—H...O hydrogen bonds into [001] chains which incorporate R₁²(6) loops. A very weak C—H...π contact also occurs.

Methyl 2,4-dihy­droxy-5-(2-methyl­propanamido)­benzoate

In the title compound, C₁₂H₁₅NO₅, the dihedral angle between the benzene ring and the C atoms of the terminal isopropyl group is 83.48 (16)°. Intra­molecular N—H...O and O—H...O hydrogen bonds generate S(5) and S(6) rings, respectively. In the crystal, mol­ecules are linked by O—H...O hydrogen bonds, generating C(7) chains propagating in [001]. Weak aromatic π–π stacking [centroid–centroid separation = 3.604 (3) Å] is also observed.

4-(1-Methyl­eth­yl)-N-((E)-4-{[1-(prop-2-en-1-yl)-1H-1,2,3-triazol-4-yl]meth­oxy}benzyl­idene)aniline

In the title compound, C₂₂H₂₄N₄O, the terminal and central benzene rings make dihedral angles of 52.7 (3) and 43.8 (2)°, respectively, with the triazole ring. The dihedral angle between the benzene rings is 8.9 (2)°. The crystal structure features C—H...π inter­actions. The atoms of the terminal propenyl group are disordered over two sets of sites, with a refined occupancy ratio of 0.714 (14):0.286 (14).

(O-Methyl di­thio­carbonato-κS)tri­phenyl­tin(IV)

In the title compound, [Sn(C₆H₅)₃(C₂H₃OS₂)], the Sn^IV atom adopts a distorted SnC₃S tetra­hedral coordination geometry. A short Sn...O contact [2.988 (4) Å] is also present. The phenyl rings are each disordered over two sets of sites with an occupancy ratio of 0.550 (8):0.450 (8). The crystal studied was found to be a racemic twin with a twin component ratio of 0.57 (18):0.43 (18).

3-Chloro-4-[2-(4-chloro­benzyl­idene)hydrazinyl­idene]-1-methyl-3,4-dihydro-1H-2λ⁶,1-benzothia­zine-2,2-dione

In the title compound, C₁₆H₁₃Cl₂N₃O₂S, the dihedral angle between the aromatic rings is 6.62 (2)° and the C=N—N=C torsion angle is 176.2 (4)°. The thia­zine ring shows an envelope conformation, with the S atom displaced by 0.633 (6) Å from the mean plane of the other five atoms (r.m.s. deviation = 0.037 Å). The Cl atom is an an axial conformation and is displaced by 2.015 (6) Å from the thia­zine ring plane. In the crystal, mol­ecules are linked by C—H...O inter­actions, generating a three-dimensional network. Very weak aromatic π–π stacking inter­actions [centroid–centroid separations = 3.928 (2) Å] are also observed.

2-(3-Chloro­benzo­yl)-3-(3,4-di­chloro­phen­yl)-1-(4-ferrocenylphen­yl)guanidine

In the title compound, [Fe(C₅H₅)(C₂₅H₁₇Cl₃N₃O)], the isolated cyclo­penta­dienyl (Cp) ring is disordered over two set of sites in a 0.577 (8):0.423 (8) ratio. The dihedral angle between the other Cp ring and its attached benzene ring is 13.6 (3)°, and that between the benzene ring and the guanidine group is 64.8 (2)°. One of the N—H groups forms both an intra- and an inter­molecular N—H...O hydrogen bond; the other N—H group does not form any hydrogen bonds. In the crystal, pairs of the inter­molecular N—H...O hydrogen bonds link the mol­ecules into inversion dimers.

4,4,6a,6b,11,12,14b-Heptamethyl-16-oxo-1,2,3,4,4a,5,6,6a,6b,7,8,9,10,11,12,12a,14a,14b-octa­deca­hydro-12b,8a-(epoxy­methano)­picen-3-yl acetate

The title compound, C₃₂H₄₈O₄, which was extracted from the bark of Rhododendron arboreum, consists of five fused rings to which an acetate and seven methyl groups are attached. The A, D and E rings adopt chair conformations, the B ring is in a distorted chair and the C ring is in a half-chair conformation. The five-membered ring formed by the lactone group, which bridges from the A/B to the B/C ring junctions, is an approximate envelope with the C atom of the methyne group as the flap [displacement from the other four atoms = 0.753 (2) Å]. There are no identified directional inter­actions in the crystal structure.

6-[(2,4-Di­methyl­anilino)methyl­idene]-2-hy­droxy­cyclo­hexa-2,4-dienone

In the title compound, C₁₅H₁₅NO₂, the dihedral angle between the aromatic rings is 5.86 (6)°, and an intra­molecular N—H...O hydrogen bond generates an S(6) motif, which helps to stabilize the enamine–keto tautomer. An intra­molecular O—H...O hydrogen bond also occurs. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds generate R₂²(10) loops. A C—H...O inter­action links the dimers into [010] chains and aromatic π–π stacking [centroid–centroid separation = 3.6131 (9) Å] also occurs.

N′-[(E)-4-Bromo­benzyl­idene]pyrazine-2-carbohydrazide

In the title compound, C₁₂H₉BrN₄O, the N′-methyl­idene­pyrazine-2-carbohydrazide and 4-bromobenzene groups are oriented at a dihedral angle of 10.57 (7)°. The hydrazide N—H group is involved in intra­molecular N—H...N inter­action, which generates an S(5) motif. A short C—H...O inter­action is formed between the methyl­idene H atom and the carbonyl O atom. It connects mol­ecules into chains extending along [100]. In addition, mol­ecules are arranged into stacks extending along [010] via π–π inter­actions between pyrazine and benzene rings, with centroid–centroid distances of 3.837 (2) and 3.860 (2) Å.

1,3-Bis[(5-amino­furan-2-yl)meth­yl]-3,4,5,6-tetra­hydro­pyrimidin-1-ium hexa­fluoro­phosphate

The asymmetric unit of the title salt, C₁₆H₂₁N₂O₂⁺·PF₆⁻, contains half of the whole ion pair, which has crystallographic mirror symmetry. Two F atoms related by the mirror plane are disordered over two sites of equal occupancy. The dihedral angle between the central ring and the furan ring is 59.3 ()°. In the crystal, the anions and cations are linked through C—H...F inter­actions, forming a three-dimensional network.

2-(3,5-Dioxo-4-aza­tri­cyclo­[5.2.1.0^2,6]dec-8-en-4-yl)acetic acid

The asymmetric unit of the title compound, C₁₁H₁₁NO₄, contains two mol­ecules, A and B, with different conformations: in mol­ecule A, the norborne and carb­oxy­lic acid groups lie to the same side of the heterocycle, whereas in a mol­ecule B, they lie on opposite sides. In the crystal, the A mol­ecules form R₂²(8) carb­oxy­lic acid inversion dimers, linked by pairs of O—H...O hydrogen bonds. The B mol­ecules link to one of the ketone O atoms of the A mol­ecule by an O—H...O inter­action, resulting in tetra­mers (two A and two B mol­ecules). The tetra­mers are linked by weak C—H...O inter­actions, generating a three-dimensional network.

N′-[(E)-1-(2-Hy­droxy­phen­yl)ethyl­idene]pyrazine-2-carbohydrazide

The title compound, C₁₃H₁₂N₄O₂, crystallized with two independent mol­ecules (A and B) in the asymmetric unit. Mol­ecule B is planar to within 0.044 (3) Å for all non-H atoms, while mol­ecule A is slightly twisted, with a dihedral angle of 6.29 (4)° between the mean planes of the pyrazine-2-carbohydrazide and 1-(2-hy­droxy­phen­yl)ethanone moieties (r.m.s. deviations = 0.0348 and 0.0428 Å, respectively). S(5) and S(6) ring motifs are formed in both mol­ecules due to the presence of intra­molecular O—H...N and N—H...N hydrogen bonds. In the crystal, mol­ecules A and B are linked by a C—H...O hydrogen bond. They stack along the a-axis direction, forming columns with π–π inter­actions involving inversion-related pyrazine and benzene rings [centroid–centroid distances = 3.5489 (13)–3.8513 (16) Å].

N′-[(E)-3-Bromo­benzyl­idene]pyrazine-2-carbohydrazide

In the title compound, C₁₂H₉BrN₄O, the dihedral angle between the aromatic rings is 12.16 (12)°. An intra­molecular N—H...N hydrogen bond closes an S(5) ring. In the crystal, C—H...O hydrogen bonds link the mol­ecules into C(6) chains propagating in [010]. Very weak aromatic π–π stacking [centroid–centroid separations = 3.9189 (15) and 3.9357 (15) Å] is also observed.

Ethyl 2-[1-(3-methyl­but­yl)-4-phenyl-1H-1,2,3-triazol-5-yl]-2-oxo­acetate

In the title compound, C₁₇H₂₁N₃O₃, the non-planar (r.m.s. deviation = 0.212 Å) ethyl (oxo)acetate group is oriented towards the phenyl substituent. The triazole and benzene rings are twisted with respect to each other, making a dihedral angle of 41.69 (6)°. In the crystal, mol­ecules are arranged into centrosymmetric R₂²(10) dimers via pairs of C—H...O inter­actions involving the ethyl (oxo)acetate groups. In addition, the triazole rings show π–π stacking inter­actions, with their centroids at a distance of 3.745 (2) Å.