In the title di-hydro-dioxin, C31H28O5, the dioxane ring has a chair conformation, whereas each of the pyran and dioxine rings has an envelope conformation with methyl-ene and quaternary C atoms, respectively, being the flap atoms. The phenyl rings are cis and form a dihedral angle of 82.11 (10)°. The molecular structure is stabilized by C-H⋯O contacts. In the crystal packing, supra-molecular layers parallel to (101) are sustained by C-H⋯π inter-actions.
3,6,11-trihy-droxy-1,1-dimethyl-2,3-di-hydro-chromeno[2,3-f]chromen-7-one monohydrate), known as pruniflorone N, crystallized as a monohydrate, C18H16O6·H2O. The three ring systems of the xanthone skeleton are approximately coplanar, with an r.m.s. deviation of 0.0270 (1) Å from the plane through the 14 non-H atoms. The O atoms of the two hy-droxy substituents on the benzene rings also lie close to this plane, with deviations of 0.019 (1) and 0.070 (1) Å. The 2'-hy-droxy-4',4'-di-methyl-pyran ring is disordered over two positions with a 0.798 (3):0.202 (3) site-occupancy ratio. An intra-molecular O-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, the xanthone and water mol-ecules are linked into a three-dimensional network by O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions. π-π inter-actions, with centroid-centroid distances of 3.5982 (7), 3.6081 (7) and 3.6456 (7) Å, are also observed.
The asymmetric unit of the title co-crystal, 2C14H13N2 (+)·C10H4O8 (2-)·2C14H12N2·C10H6O8, comprises a 2,9-dimethyl-1,10-phenanthrolin-1-ium cation (Me2PhenH(+)) and a 2,9-dimethyl-1,10-phenanthroline mol-ecule (Me2Phen), each in a general position, and half each of a 2,5-di-carb-oxy-benzene-1,4-di-carboxyl-ate dianion (LH2 (2-)) and a benzene-1,2,4,5-tetra-carb-oxy-lic acid mol-ecule (LH4), each being disposed about a centre of inversion. Small twists are evident in the dianion [the C-C-C-O torsion angles are 168.41 (18) and 16.2 (3)°], whereas a major twist is found for one carb-oxy-lic acid group in the neutral mol-ecule [C-C-C-O = 66.3 (2) and 18.2 (3)°]. The most prominent feature of the crystal packing is the formation of linear supra-molecular chains along  mediated by charge-assisted O-H⋯O(-) hydrogen bonding between alternating LH4 and LH2 (2-). These are connected to the Me2PhenH(+) and Me2Phen species by N-H⋯O and O-H⋯N hydrogen bonds, respectively. A three-dimensional architecture is formed by C-H⋯O and π-π inter-actions [inter-centroid distance = 3.5337 (17) Å].
In the title compound, C16H20O6, the conformation about the C=C double bond [1.344 (2) Å] is Z. With respect to this bond, the ketone is almost coplanar [C-C-C-O torsion angle = -179.60 (10)°] and the ester is almost perpendicular [C-C-C-O = 78.42 (13)°]. The meth-oxy substituents of the central benzene ring are either almost coplanar [C-C-O-C = 3.54 (15) and 177.70 (9)°] or perpendicular [C-C-O-C = 80.08 12)° for the central substituent]. In the crystal, the three-dimensional architecture features C-H⋯O and π-π [inter-centroid distance = 3.6283 (6) Å] inter-actions.
The asymmetric unit of the title co-crystal, C10H6O8·2C8H10N4O2, comprises a centrosymmetric benzene-1,2,4,5-tetra-carb-oxy-lic acid (LH4) mol-ecule and a mol-ecule of caffeine in a general position. LH4 is nonplanar, with the dihedral angles between the ring and pendent carb-oxy-lic acid groups being 44.22 (7) and 49.74 (7)°. By contrast, the caffeine mol-ecule is planar (r.m.s. deviation = 0.040 Å). Supra-molecular layers parallel to (-1-10) are sustained by carb-oxy-lic acid O-H⋯O(carbon-yl) and O-H⋯N(imidazole) hydrogen bonds, as well as by meth-yl-carbonyl C-H⋯O inter-actions. These stack via π-π inter-actions between the benzene and imidazole rings [inter-centroid distance = 3.4503 (10) Å].
Refluxing a mixture of 1,10-phenanthroline, (4-fluoro-phen-yl)thio-urea and cadmium(II) chloride did not produce the expected mixed-ligand complex but formed a co-crystal of the two ligands, C12H8N2·C7H7FN2S. The asymmetric unit consists of two pairs of the co-crystal mol-ecules. In each (4-fluoro-phen-yl)thio-urea mol-ecule, the planes of the N2CS thio-urea units are almost perpendicular to the corresponding fluoro-benzene rings, subtending angles of 76.53 (7) and 85.25 (7)°. In the crystal, N-H⋯N and N-H⋯S hydrogen bonds form inversion dimers from the co-crystal pairs. A weak π-π inter-action between the phenanthroline rings [centroid-centroid distance = 3.7430 (15)Å] is also observed.
The asymmetric unit of title co-crystal, C10H8N2·2C7H7NO2, comprises a centrosymmetric 4,4'-bi-pyridine mol-ecule, and a 2-amino-benzoic acid mol-ecule in a general position. The latter is effectively planar [C-C-C-O torsion angle = 5.0 (3)°] owing to an intra-molecular N-H⋯O(carbon-yl) hydrogen bond. Three-mol-ecule aggregates are formed via O-H⋯N(pyrid-yl) hydrogen bonds and these are connected into supra-molecular layers in the bc plane by N-H⋯O(carbon-yl) hydrogen bonds and π-π inter-actions between pyridyl and benzene rings [inter-centroid distance = 3.634 (2) Å]. Layers are connected along the a axis by weak π-π inter-actions between benzene rings [3.964 (2) Å].
In the title mol-ecule, C15H22O2, there is an intra-molecular hydrogen bond involving the hy-droxy and aldehyde groups and forming an S(6) ring. The mean plane of the non-H atoms of this ring [(H)O-C C-C=O, with a maximum deviation of 0.013 (1) Å] are essentially coplanar with the benzene ring, forming a dihedral angle of 2.29 (8)°.
The title salt crystallized as the monohydrate C15H16NO2 (+)·C6H4BrSO3 (-)·H2O. The cation exists in an E conformation with respect to the ethynyl bond and is essentially planar, with a dihedral angle of 6.52 (14)° between the pyridinium and the benzene rings. The hy-droxy and meth-oxy substituents are coplanar with the benzene ring to which they are attached, with an r.m.s. deviation of 0.0116 (3) Å for the nine non-H atoms [Cmeth-yl-O-C-C torsion angle = -0.8 (4)°]. In the crystal, the cations and anions are stacked by π-π inter-actions, with centroid-centroid distances of 3.7818 (19) and 3.9004 (17) Å. The cations, anions and water mol-ecules are linked by O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions, forming a three-dimensional network.
In the title compound, C20H26N2S, the N-containing six-membered ring adopts a boat conformation and the dihedral angle between the thio-carbamide group and the benzene ring is 49.67 (9)°. An intra-molecular C-H⋯S hydrogen bond generates an S(6) ring motif. The N-H group is sterically hindered and there are no significant inter-molecular inter-actions beyond van der Waals contacts.
In the structure of the title nicotino-nitrile derivative, C19H15N3O, the pyridine ring makes dihedral angles of 11.50 (7) and 43.36 (8)° with the 4-amino-phenyl and phenyl rings, respectively, and the dihedral angle between the phenyl rings is 36.28°. In the crystal, mol-ecules are linked by N-H⋯N hydrogen bonds into wave-like sheets parallel to (10-2). These sheets are stacked by π-π inter-actions between the 4-amino-phenyl rings of adjacent sheets, with centroid-centroid distances of 3.7499 (9) Å. C-H⋯π inter-actions are also present.
The title compound, [CuCl2(C19H16N4O)], contains a Cu(II) atom N,N',O-chelated by a neutral N-phenyl-hy-dra-zine-car-box-amide ligand and additionally coordinated by two Cl atoms, resulting in a distorted square-pyramidal geometry. The ligating atoms in the basal square plane of the complex comprise the azomethine N, the pyridine N, the amide O and one of the Cl atoms, whereas the other Cl atom occupies an apical position. The apical Cl atoms in adjacent layers function as hydrogen-bond acceptors to both NH groups. Intermolecular C-H⋯Cl and C-H⋯O interactions are also observed.
In the title salt, C6H14N(+)·NO3 (-), the cyclo-hexyl ring adopts a chair conformation. The ammonium group occupies an equatorial position and the crystal struture is stabilized by inter-molecular N-H⋯O hydrogen-bonding inter-actions, resulting in a three-dimensional network.
In the cation of the title salt, C11H17N2O(+)·C7H8ClN2O2 (-), the piperazine ring adopts a distorted chair conformation and contains a positively charged N atom with quaternary character. Its mean plane makes a dihedral angle of 42.36 (8)° with the phenyl ring of its 2-meth-oxy-phenyl substituent. The 2,4-dioxopyrimidin-1-ide anion is generated by deprotonation of the N atom at the 1-position of the pyrimidine-dione ring. Intra-molecular C-H⋯O hydrogen bonds generate S(6) ring motifs in both the cation and the anion. In the crystal, N-H⋯O, N-H⋯N and C-H⋯O hydrogen bonds are also observed, resulting in a two-dimensional network parallel to the ab plane. The crystal stability is further consolidated by weak C-H⋯π inter-actions.
In the title compound, C19H17N5S, the dihedral angles between the purine ring system (r.m.s. deviation = 0.009 Å) and the S-bound and methyl-ene-bound phenyl rings are 74.67 (8) and 71.28 (7)°, respectively. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R 2 (2)(8) loops. C-H⋯N inter-actions link the dimers into (100) sheets.
In the title compound, C8H7N3O4 (systematic name: 4-nitro-benzene-1,2-dicarboxamide), each of the substituents is twisted out of the plane of the benzene ring to which it is attached [dihedral angles of 11.36 (2)° for the nitro group, and 60.89 (6) and 34.39 (6)° for the amide groups]. The amide groups are orientated to either side of the least-squares plane through the benzene ring with the amine groups being directed furthest apart. In the crystal, a three-dimensional architecture is established by a network of N-H⋯O hydrogen bonds.
In the title compound, C8H3N3O2 (systematic name: 4-nitro-benzene-1,2-dicarbo-nitrile), the nitro group is twisted out of the plane of the benzene ring to which it is attached [O-N-Cring-Cring torsion angle = 9.80 (13)°]. In the crystal packing, supra-molecular layers with a zigzag topology in the ac plane are sustained by C-H⋯N inter-actions.
The asymmetric unit of the title cyclic thio-urea derivative, C10H12N2S, comprises two mol-ecules, each of which has a twist about the CH2-CH2 bond within the five-membered ring. The major difference between the independent mol-ecules is manifested in the relative orientations of the five- and six-membered rings [dihedral angles between the least-squares planes = 28.03 (11) and 41.54 (11)°]. A network of C-H⋯π inter-actions consolidates the three-dimensional crystal packing.
In the title compound, C12H14Cl2N2O2S, the mol-ecule adopts a cis conformation with respect to the di-chloro-benzoyl group against the thiono group about the C-N bond. However, the di-chloro-benzene group and the thio-urea moiety are twisted by 75.41 (8)°. An intra-molecular N-H⋯O hydrogen bond occurs between the amido H atom and hydroxyl O atom. In the crystal, O-H⋯S and O-H⋯O hydrogen bonds link the molecules, forming chains along the b-axis direction.
In the title compound, C26H37N5OS, the piperazine ring adopts a chair conformation. The triazole ring forms dihedral angles of 67.85 (9) and 59.41 (9)° with the piperazine and benzene rings, respectively, resulting in an approximate V-shaped conformation for the mol-ecule. An intra-molecular C-H⋯O hydrogen bond generates an S(6) ring motif. The crystal structure features C-H⋯π inter-actions, producing a two-dimensional supramolecular architecture.