The title compound has an E conformation about the azobenzene linkage and the benzene rings are almost coplanar to one another [dihedral angle = 1.36 (7)°]. In the crystal, a combination of O—H⋯O and C—H⋯O hydrogen bonds and C—H⋯π interactions leads to the formation of slabs parallel to (001).
The title compound, C16H14N2O3, has an E conformation about the azobenzene [—N=N– = 1.2481 (16) Å] linkage. The benzene rings are almost coplanar [dihedral angle = 1.36 (7)°]. The O atoms of the carboxylic acid group are disordered over two sets of sites and were refined with an occupancy ratio of 0.5:0.5. The two disordered components of the carboxylic acid group make dihedral angles of 1.5 (14) and 3.8 (12)° with the benzene ring to which they are attached. In the crystal, molecules are linked via pairs of O—H⋯O hydrogen bonds, forming inversion dimers. The dimers are connected via C—H⋯O hydrogen bonds, forming ribbons lying parallel to . These ribbons are linked via C—H⋯π interactions, forming slabs parallel to (001).
crystal structure; azobenzene; benzoic acid; liquid crystal; nematic phase
The asymmetric unit of the title compound, C17H18O3, comprises three independent molecules with similar geometries. In each molecule, the carbonyl group is twisted away from the napthalene ring system, making dihedral angles of 1.0 (2), 1.05 (19)° and 1.5 (2)°. The butene group in all three molecules are disordered over two sets of sites, with a refined occupancy ratio of 0.664 (6):0.336 (6). In the crystal, molecules are oriented with respect to their carbonyl groups, forming head-to-head dimers via O—H⋯O hydrogen bonds. Adjacent dimers are further interconnected by C—H⋯O hydrogen bonds into chains along the a-axis direction. The crystal structure is further stabilized by weak C—H⋯π interactions.
In the title compound, C24H23NO2, a whole molecule is disordered over two sets of sites with occupancies in a ratio of 0.692 (6):0.308 (6). In the major disorder component, the naphthalene ring system forms a dihedral angle of 68.6 (5)° with the benzene ring. The corresponding angle in the minor component is 81.6 (10)°. In the crystal, molecules are linked into chains propagating along the b-axis direction via weak C—H⋯O hydrogen bonds. The crystal packing is further consolidated by weak C—H⋯π interactions.
The title compound, C20H28O3, known as ‘trichodermaerin’ [systematic name: (4E)-4,9,15,16,16-pentamethyl-6-oxatetracyclo[10.3.1.01,10.05,9]hexadec-4-ene-7,13-dione], is a diterpene lactone which was isolated from Trichoderma asperellum. The structure has a tetracycic 6–5–7–5 ring system, with the cyclohexanone ring adopting a twisted half-chair conformation and the cyclopentane ring adopting a half-chair conformation, whereas the cycloheptene and tetrahydrofurananone rings are in chair and envelope (with the methyl-substituted C atom as the flap) conformations, respectively. The three-dimensional architecture is stabilized by C—H⋯O interactions.
The asymmetric unit of the title hydrated salt, C22H25N2
+·C6H4ClO3S−·H2O, comprises two 2-[4-(diethylamino)styryl]-1-methylquinolin-1-ium cations, two 4-chlorobenzenesulfonate anions and two solvent water molecules. One ethyl group of both cations displays disorder over two positions in a 0.659 (2):0.341 (2) ratio in one molecule and in a 0.501 (2):0.499 (2) ratio in the other. The sulfonate group of one anion is also disordered over two positions in a 0.893 (7):0.107 (7) ratio. The dihedral angle between the mean plane of the quinolinium ring system and that of benzene ring is 10.57 (18)° in one cation and 14.4 (2)° in the other. In the crystal, cations, anions and water molecules are linked into chains along the  direction by O—H⋯Osulfonate hydrogen bonds, together with weak C—H⋯Osulfonate and C—H⋯Cl interactions. The cations are stacked by π–π interactions, with centroid–centroid distances in the range 3.675 (2)–4.162 (3) Å.
The title compound crystallizes as a hemihydrate, C18H20N2O5·0.5H2O. The molecule exists in an E conformation with respect to the C=N imine bond. The 4-methoxyphenyl unit is disordered over two sets of sites with a refined occupancy ratio of 0.54 (2):0.46 (2). The dihedral angles between the benzene rings are 29.20 (9) and 26.59 (9)°, respectively, for the major and minor components of the 4-methoxy-substituted ring. All methoxy substituents lie close to the plane of the attached benzene rings [the Cmethyl—O—C—C torsion angles range from −4.0 (12) to 3.9 (2)°]. In the crystal, the components are linked into chains propagating along  via N—H⋯O and O—H⋯O hydrogen bonds and weak C—H⋯O interactions.
There are two independent molecules in the asymmetric unit of the title compound, C16H17NO4, with similar conformations but some differences in their bond angles. Each molecule adopts a trans configuration with respect to the methylidene C=N bond and is twisted with a dihedral angle between the two substituted benzene rings of 80.52 (7)° in one molecule and 83.53 (7)° in the other. All methoxy groups are approximately coplanar with the attached benzene rings, with Cmethyl—O—C—C torsion angles ranging from −6.7 (2) to 5.07 (19)°. In the crystal, independent molecules are linked together by O—H⋯N and O—H⋯O hydrogen bonds and a π–π interaction [centroid–centroid distance of 3.6030 (9) Å], forming a dimer. The dimers are further linked by weak C—H⋯O interactions and another π–π interaction [centroid–centroid distance of 3.9452 (9) Å] into layers lying parallel to the ab plane.
In the structure of the title salt, C20H20NO+·C6H4FO3S−, the 4-(ethoxyphenyl)ethenyl unit is disordered over two positions with a refined site-occupancy ratio of 0.610 (6):0.390 (6). The cation is nearly planar, the dihedral angle between the quinolinium and benzene rings being 6.7 (4) and 1.7 (7)° for the major and minor components, respectively. The ethoxy group is essentially coplanar with the benzene ring [C—O—C—Cmethy = 177.1 (8) and 177.8 (12)° for the major and minor components, respectively]. In the crystal, cations and anions are linked into chains along the b-axis direction by C—H⋯Osulfonyl weak interactions. These chains are further connected into sheets parallel to (001) by C—H⋯Osulfonyl weak interactions. The chains are also stacked along the a axis through π–π interactions involving the quinolinium and benzene rings [centroid–centroid distances = 3.636 (5) Å for the major component and 3.800 (9) Å for the minor component]. C—H⋯π interactions are also present.
In the structure of the title nicotinonitrile derivative, C19H15N3O, the pyridine ring makes dihedral angles of 11.50 (7) and 43.36 (8)° with the 4-aminophenyl and phenyl rings, respectively, and the dihedral angle between the phenyl rings is 36.28°. In the crystal, molecules are linked by N—H⋯N hydrogen bonds into wave-like sheets parallel to (10-2). These sheets are stacked by π–π interactions between the 4-aminophenyl rings of adjacent sheets, with centroid–centroid distances of 3.7499 (9) Å. C—H⋯π interactions are also present.
In the title mixed salt, 2C16H15N2
−, one of the cations shows whole molecule disorder over two sets of sites in a 0.711 (7):0.289 (7) ratio. The 4-chorobenzenesulfonate anion is also disordered over two orientations in a 0.503 (6):0.497 (6) ratio. The cations are close to planar, the dihedral angles between the pyridinium and indole rings being 1.48 (3)° in the ordered cation, and 5.62 (3) and 2.45 (3)°, respectively, for the major and minor components of the disordered cation. In the crystal, the cations are stacked in an antiparallel manner approximately along the a-axis direction and linked with the anions via N—H⋯O hydrogen bonds and C—H⋯O interactions, generating a three-dimensional network. Weak C—H⋯π and π–π interactions [with centroid–centroid distances of 3.561 (2)–3.969 (7) Å] are also observed.
In the title 3-cyanopyridine derivative, C21H19N3O4, the 3-cyano-substituted pyridine ring forms dihedral angles of 2.35 (5) and 41.60 (5)° with the unsubstituted pyridine and 2,4,5-trimethoxy-substituted benzene rings, respectively. The dihedral angle between the unsubstituted pyridine and benzene rings is 39.84 (5)°. The methoxy groups form Cmethyl—O—C—(C,N) torsion angles in the range 0.80 (15)–11.45 (15)°. In the crystal, molecules related by 21 screw axes are linked by weak C—H⋯N hydrogen bonds along . In addition, weak C—H⋯π interactions and π–π stacking interactions between pyridine rings, with a centroid–centroid distance of 3.6448 (6) Å, are observed.
In the title compound, C13H12O5, the mean plane of the 2H-chromene ring system (r.m.s deviation = 0.026 Å) forms a dihedral angle of 81.71 (6)° with the mean plane of ethyl 2-hydroxyacetate moiety (r.m.s deviation = 0.034 Å). In the crystal, C—H⋯O hydrogen bonds result in the formation of zigzag layers parallel to the bc plane.
In the title compound, C14H17N3O2, the mean plane of the 1,8-naphthyridine ring system (r.m.s deviation = 0.020 Å) forms a dihedral angle of 23.4 (1)° with the acetamide moiety (r.m.s deviation = 0.001 Å). The molecular structure is stabilized by an intramolecular O—H⋯N hydrogen bond, which generates an S(5) ring motif. In the crystal, molecules are linked into inversion dimers by pairs of N—H⋯O hydrogen bonds, generating 18-membered R
2(18) ring motifs.
The asymmetric unit of the title compound, C18H18ClN3OS·C2H5OH, comprises a pyrazoline derivative and an ethanol solvent molecule. In the molecule of the pyrazoline derivative, the pyrazole ring adopts an envelope conformation with the C atom bearing the ethoxyphenyl substituent as the flap. The dihedral angle between the benzene rings is 74.22 (7)°. The ethoxy group is coplanar with the attached benzene ring [C—O—C—Cmethyl = 175.50 (11)° and r.m.s. deviation = 0.0459 (1) Å for the nine non-H atoms]. In the crystal, the pyrazoline molecules are linked by N—H⋯Oethoxy hydrogen bonds into chains along the c axis and are further linked with the solvent ethanol molecules by N—H⋯Oethanol and Oethanol—H⋯S hydrogen bonds. C—H⋯π interactions are also present.
In the title hydrated salt, C19H25N2
+·I−·H2O, the 4-(diethylamino)phenyl unit of the cation is disordered over two positions in a 0.847 (3):0.153 (3) ratio. The cation is twisted, with dihedral angles between the pyridinium and benzene rings of 11.25 (13) and 10.7 (8)° for the major and minor components, respectively. In the crystal, the three components are linked into a centrosymmetric 2:2:2 unit by O—H⋯I and C—H⋯O hydrogen bonds. π–π interactions with centroid–centroid distances of 3.5065 (7)–3.790 (9) Å are also present.
The molecule of the title compound, C16H10N2OS, is approximately planar, the dihedral angle between the 1,3-benzothiazolo[3,2-a]imidazol-3(2H)-one and the benzylidene moieties being 4.10 (8)°. A weak intramolecular C—H⋯S interaction generates an S(6) ring. No intermolecular hydrogen bonds are observed in the crystal structure.
The title compound, C21H17NO2, exists in an E conformation with respect to the C=C bond. The pyridine ring forms dihedral angles of 5.57 (7) and 82.30 (9)°, respectively, with the central benzene ring and the terminal phenyl ring. The dihedral angle between the benzene and phenyl rings is 87.69 (8)°. No significant intermolecular interactions are observed.
The asymmetric unit of the title compound, C23H18N2O3S, contains two molecules with comparable geometries. In one molecule, the pyrazole ring forms dihedral angles of 61.65 (11), 47.88 (11) and 63.20 (14)° with the three benzene rings. The corresponding values for the other molecule are 77.19 (11), 43.55 (11) and 63.56 (15)°. In the crystal, both molecules are linked into inversion dimers by pairs of C—H⋯S hydrogen bonds, generating R
2(14) loops in each case.
In the title compound, C8H12N2O, the piperidine ring exhibits a chair conformation and its least-squares plane (all atoms) makes a dihedral angle of 32.88 (12)° with the propanenitrile unit (r.m.s. deviation = 0.001 Å). In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming chains along .
In the title compound, C24H18N2O3S, the benzofuran ring system (r.m.s. deviation = 0.010 Å) forms dihedral angles of 83.13 (17) and 8.92 (14)° with the benzene and thiazole rings, respectively. The dihedral angle between the benzene and thiazole rings is 84.51 (19)°. The molecular structure features an intramolecular C—H⋯O hydrogen bond, which closes an S(6) ring. There are no intermolecular hydrogen bonds observed in this structure.
In the title compound, C20H21N3O2S, the 2,3-dihydro-1H-pyrazole ring is nearly planar (r.m.s. deviation = 0.023 Å) and forms dihedral angles of 16.96 (6) and 38.93 (6)° with the benzene and phenyl rings, respectively. The dihedral angle between the benzene and phenyl rings is 55.54 (6)°. The molecular conformation is consolidated by an intramolecular C—H⋯O hydrogen bond, which forms an S(6) ring. In the crystal, inversion dimers linked by pairs of N—H⋯Op (p = pyrazole) hydrogen bonds generate R
2(10) loops. The dimers are linked by C—H⋯O hydrogen bonds into sheets lying parallel to (100).
In the title compound, C16H16BrNO, the dihedral angle between the benzene rings is 69.8 (2)°. In the crystal, N—H⋯O hydrogen bonds link the molecules into C(4) chains propagating in . Adjacent molecules in the chains are also linked by C—H⋯O interactions which, along with the N—H⋯O hydrogen bonds, generate R
In the title compound, C11H9ClN2OS, the thiazole ring is nearly planar (r.m.s. deviation = 0.003 Å) and forms a dihedral angle of 64.18 (7)° with the bezene ring. In the crystal, inversion dimers linked by pairs of N—H⋯Nt (t = thiazole) hydrogen bonds generate R
The asymmetric unit of the title compound, C16H14ClN3OS, contains two independent molecules (A and B) linked into dimers via N—H⋯N hydrogen bonds. The 1,3-benzothiazol-2-yl ring system and the benzene ring form dihedral angles of 17.08 (8) and 8.63 (7)° in molecules A and B, respectively.
In the title compound, C18H14BrNO, the naphthalene ring system [maximum deviation = 0.015 (3) Å] forms a dihedral angle of 67.70 (10)° with the benzene ring. In the crystal, molecules are linked by N—H⋯O hydrogen bonds into C(4) chains propagating in . A C—H⋯O interaction reinforces the chain connectivity, generating an R