5-Hy­droxy-2-{(E)-[(3-nitro­phen­yl)iminio]meth­yl}phenolate

The title compound, C₁₃H₁₀N₂O₄, crystallized as the zwitterionic tautomer. As a result, the phenolate C—O⁻ bond [1.296 (2) Å] is shorter than a normal Csp²—O(H) bond, and the azomethine C=N bond [1.314 (2) Å] is longer than a normal C=N double bond. The mol­ecule is nearly planar, the mean plane of the nitro-substituted benzene ring forming dihedral angles of 9.83 (7) and 8.45 (9)° with the other benzene ring and with the nitro group, respectively. The mol­ecular conformation is stabilized by an intra­molecular N—H...O hydrogen bond. In the crystal, strong O—H...O hydrogen bonds link the mol­ecules into double-stranded chains along the b-axis direction. Within the chains there are π–π interactions involving the benzene rings of adjacent molecules [centroid–centroid distance = 3.669 (1) Å]. The chains are linked via C—H...O hydrogen bonds, forming R₂¹(6), R₂¹(7) and R₂²(10) ring motifs.

An ortho­rhom­bic polymorph of 2-(1,3-benzothia­zol-2-yl)-6-eth­oxy­phenol

In the title mol­ecule, C₁₅H₁₃NO₂S, an intra­molecular O—H...N hydrogen bond forms an S(6) ring motif. The benzothia­zole ring system and the benzene ring form a dihedral angle of 8.9 (3) Å. In the crystal, mol­ecules are linked by weak C—H...O hydrogen bonds, forming chains along the b axis. In addition, π–π inter­actions [centroid–centroid distances = 3.772 (4) and 3.879 (4) Å] are observed.

4-Bromo-2-[(E)-(2-{2-[(2-{[(E)-5-bromo-2-hy­droxy­benzyl­idene]amino}­phen­yl)sulfan­yl]ethyl­sulfan­yl}phen­yl)imino­meth­yl]phenol

The asymmetric unit of the title compound, C₂₈H₂₂Br₂N₂O₂S₂, comprises half of a Schiff base ligand, the whole mol­ecule being generated by a crystallographic inversion center located at the mid-point of the C—C bond of the central methyl­ene segment. Intra­molecular O—H...N and O—H...S hydrogen bonds make S(6) and S(5) ring motifs, respectively. In the crystal, there are no significant inter­molecular inter­actions.

2-(6-Meth­oxy­naphthalen-2-yl)-1-(morpholin-4-yl)propan-1-one

In the title compound, C₁₈H₂₁NO₃, the naphthalene group and the basal plane of the morpholine ring (r.m.s. deviations = 0.0177 and 0.0069 Å, respectively) are oriented at a dihedral angle of 44.0 (2)°. In the crystal, mol­ecules are linked by C—H...π inter­actions.

2-(4-Isobutyl­phen­yl)-1-(morpholin-4-yl)propan-1-one

In the title compound, C₁₇H₂₅NO₂, the morpholine ring adopts a chair conformation. The benzene ring makes a dihedral angle of 39.81 (13)° with the basal plane of the morpholine group.

5-(5-Bromo-2-meth­oxy­phen­yl)-2-fluoro­pyridine

In the title compound, C₁₂H₉BrFNO, the dihedral angle between the aromatic rings is 51.39 (5)°; the C atom of the meth­oxy group is close to being coplanar with its attached ring (r.m.s. deviation = 0.0172 Å] and is oriented away from the pyridine ring. In the crystal, mol­ecules inter­act by van der Waals forces.

2-Benzene­sulfonamido-3-methyl­butyric acid

In the crystal structure of the title compound, C₁₁H₁₅NO₄S, two independent mol­ecules are present per asymmetric unit; they are dimerized through O—H...O hydrogen bonds between their carb­oxy groups to generate R₂²(8) loops. An intra­molecular N—H...O link in one of the mol­ecules closes an S(5) ring. The dimers are linked by N—H...O and C—H...O hydrogen bonds to form a three-dimensional network. The C atoms of the isopropyl group of one of the mol­ecules are disordered over two orientations in a 3:1 ratio.

2-[(E)-({4-[(4,6-Dimethyl­pyrimidin-2-yl)sulfamo­yl]phen­yl}iminio)meth­yl]-6-hy­droxy­phenolate

The title compound, C₁₉H₁₈N₄O₄S, exists as a zwitterion in the solid state, with nominal proton transfer from a phenol group to the imine N atom. The 2,3-dihy­droxy­benzaldehyde fragment is oriented at a dihedral angle of 35.51 (11)° to the adajacent aniline group and makes a dihedral angle of 76.99 (6)° with the 4,6-dimethyl­pyrimidin-2-amine group. Intra­molecular O—H...O and N—H...O hydrogen bonds close S(5) and S(6) rings, respectively; the same O atom accepts both bonds. In the crystal, polymeric chains along [001] are formed from mol­ecules joined end-to-end by N—H...O and O—H...N hydrogen bonds; these feature R₂³(6) loops. The polymeric chains are linked by C—H...O inter­actions and there are π–π inter­actions between the pyrimidine rings with a centroid–centroid distance of 3.446 (2) Å.

N-(2,4-Dichloro­phen­yl)-1,3-thia­zol-2-amine

In the title mol­ecule, C₉H₆Cl₂N₂S, the mean planes of the benzene and thia­zole rings make a dihedral angle of 54.18 (8)°. In the crystal, mol­ecules are joined into dimers with an R₂²(8) ring motif by pairs of N—H...N hydrogen bonds. These dimers are linked by C—H...Cl inter­actions into layers parallel to (011). The thia­zole rings form columns along the c-axis direction, with a centroid–centroid separation of 3.8581 (9) Å, indicating π–π inter­actions. An intra­molecular C—H...S contact also occurs.

4-Bromo-2-{(E)-[(3,4-dimethyl­phen­yl)imino]­meth­yl}phenol

In the title compound, C₁₅H₁₄BrNO, the dihedral angle between the aromatic rings is 4.10 (11)° and the mol­ecule is close to planar (r.m.s. deviation for the non-H atoms = 0.053 Å). An intra­molecular O—H...N hydrogen bond closes an S(6) ring. In the crystal, very weak C—H...π inter­actions are observed.

(2Z)-N-(2-Chloro­benz­yl)-2-(2-oxo-2,3-dihydro-1H-indol-3-yl­idene)hydrazinecarbothio­amide

In the title compound, C₁₆H₁₃ClN₄OS, the isatin ring system is oriented at dihedral angles of 10.60 (7) and 72.60 (3)° with respect to the thio­semicarbazide and 2-chloro­benzyl groups, respectively. The near planarity of the isatin and thio­semicarbazide groups [r.m.s. deviations of 0.0420 and 0.0163 Å, respectively] is reinforced by intra­molecular N—H...O and N—H...N hydrogen bonds, which generate S(6) and S(5) rings, respectively. In the crystal, inversion dimers linked by pairs of N—H...O hydrogen bonds generate R₂²(8) loops. Aromatic π–π stacking inter­actions between the centroids of heterocyclic five-membered and benzene rings [distance = 3.6866 (11) Å] are also observed.

2,5-Dichloro-N-(2,3-dimethyl­phen­yl)benzene­sulfonamide

In the title compound, C₁₄H₁₃Cl₂NO₂S, the dihedral angle between the aromatic rings is 62.21 (7)° and the C—S—N—C group adopts a gauche conformation [torsion angle = 60.22 (17)°]. In the crystal, N—H...O hydrogen bonds link the mol­ecules into C(4) chains propagating in [010]. A short inter­molecular Cl...O contact of 3.1115 (17) Å is seen.