organic compounds
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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—HOsulfonyl weak interactions. These chains are further connected into sheets parallel to (001) by C—HOsulfonyl 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—Hπ interactions are also present.
organic compounds
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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—HN and O—HO 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—HO interactions and another π–π interaction [centroid–centroid distance of 3.9452 (9) Å] into layers lying parallel to the ab plane.
organic compounds
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The molecule of the title hydrazine derivative, C15H14N4O6, is essentially planar, the dihedral angle between the substituted benzene rings being 2.25 (9)°. The ethoxy and hydroxy groups are almost coplanar with their bound benzene ring [r.m.s. deviation = 0.0153 (2) Å for the ten non-H atoms]. Intramolecular N—HO and O—HOethoxy hydrogen bonds generate S(6) and S(5) ring motifs, respectively. In the crystal, molecules are linked by O—HOnitro hydrogen bonds into chains propagating in [010]. Weak aromatic π–π interactions, with centroid–centroid distances of 3.8192 (19) and 4.0491 (19) Å, are also observed.
research communications
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The NiII atom in the title compound shows a square-planar NiN2O2 coordination with the imine N and phenolate O atoms of the two Schiff base ligands. C—HO and C—Hπ interactions result in the formation of sheets of molecules parallel to the ac plane.
organic compounds
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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 [001] via N—HO and O—HO hydrogen bonds and weak C—HO interactions.
organic compounds
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Molecules of the title compound, C16H16N4O7, are not planar with a dihedral angle of 5.50 (11)° between the substituted benzene rings. The two meta-methoxy groups of the 3,4,5-trimethoxybenzene moiety lie in the plane of the attached ring [Cmethyl–O–C–C torsion angles −0.1 (4)° and −3.7 (3)°] while the para-methoxy substituent lies out of the plane [Cmethyl—O—C—C, −86.0 (3)°]. An intramolecular N—HO hydrogen bond involving the 2-nitro substituent generates an S(6) ring motif. In the crystal structure, molecules are linked by weak C—HO interactions into screw chains, that are arranged into a sheet parallel to the bc plane. These sheets are connected by π–π stacking interactions between the nitro and methoxy substituted aromatic rings with a centroid–centroid separation of 3.9420 (13) Å. C—Hπ contacts further stabilize the two-dimensional network.
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In the square-planar [Ni(C14H11FNO)2] complex, weak C—HF and C—Hπ interactions play an important role in the molecular self-assembly, resulting in the formation of 2D molecular sheets which are stacked along the b axis.
metal-organic compounds
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In the title complex, [Pd(C16H16NO2)2]·CHCl3, the PdII cation lies on an inversion center. One Cl atom of the CHCl3 solvent molecule lies on a twofold axis and the C—H group is disordered with equal occupancies about this axis with the other Cl atom in a general position with full occupancy. The PdII cation is four-coordinate and adopts a square-planar geometry via coordination of the imine N and phenolic O atoms of the two bidentate Schiff base anions. The N and O atoms of these ligands are mutually trans. The plane of the benzene ring makes a dihedral angle of 73.52 (10)° with that of the methoxyphenolate ring. In the crystal, molecules of the PdII complex are arranged into sheets parallel to the ac plane, and the chloroform solvent molecules are located in the interstitial areas between the complex molecules. Weak intermolecular C—HO and C—Hπ interactions stabilize the packing.
Keywords: crystal structure.
organic compounds
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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 [010] direction by O—HOsulfonate hydrogen bonds, together with weak C—HOsulfonate and C—HCl interactions. The cations are stacked by π–π interactions, with centroid–centroid distances in the range 3.675 (2)–4.162 (3) Å.
organic compounds
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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—HO interactions.
organic compounds
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The asymmetric unit of the title salt, C36H32N22+·2C6H4ClO3S−, consists of one anion and one half-cation, the other half being generated by inversion symmetry. The dihedral angle between the pyridinium ring and the napthalene ring system in the asymmetric unit is 42.86 (6)°. In the crystal, cations and anions are linked by weak C—HO interactions into chains along [010]. Adjacent chains are further arranged in an antiparallel manner into sheets parallel to the bc plane. π–π interactions are observed involving the cations, with centroid–centroid distances of 3.7664 (8) and 3.8553 (8) Å.
organic compounds
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There are two crystallograpically independent molecules in the asymmetric unit of the title bischalcone derivative, C25H32N2O. Both molecules are twisted with a dihedral angle between the two substituted benzene rings of 11.19 (16)° in one molecule and 14.40 (15)° in the other. The central penta-1,4-dien-3-one fragments make dihedral angles of 8.49 (17) and 4.26 (17)° with the two adjacent benzene rings in one molecule, whereas the corresponding values are 8.42 (16) and 6.18 (16)° in the other. In the crystal, molecules are arranged into chains along the c-axis direction. Adjacent chains are inter-linked by weak intermolecular C—HO interactions. The crystal is further stabilized by C—Hπ interactions.