The title compound, 3,5,7-triaza-1-azoniatricyclo[3.3.1.1(3,7)]decane 2,4-dinitrophenolate monohydrate, C6H13N4+*C6H3N2O5-*H2O, the 1:1 hydrate adduct of hexamethylenetetramine (HMT) and 2,4-dinitrophenol, undergoes a temperature phase transition. In the room-temperature phase, the adduct crystallizes in the monoclinic P2(1)/m space group, whereas in the low-temperature phase, the adduct crystallizes in the triclinic P1 space group. This phase transition is reversible, with the transition temperature at 273 K, and the phase transition is governed by hydrogen bonds and weak interactions. In both these temperature-dependent polymorphs, the crystal structure is alternately layered with sheets of hexamethylenetetramine and sheets of dinitrophenol stacked along the c axis. The hexamethylenetetramine and dinitrophenol moieties are linked by intermolecular hydrogen bonds. The water molecule in the adduct plays an important role, forming O-H...O hydrogen bonds which, together with C-H...O hydrogen bonds, bridge the adducts into molecular ribbons. Extra hydrogen bonds and weak interactions exist for the low-temperature polymorph and these interconnect the molecular ribbons into a three-dimensional packing structure. Also in these two temperature-dependent polymorphs, dinitrophenol acts as a hydrogen-bond acceptor and HMT acts as a hydrogen-bond donor.
Crystals of 1,6-hexanedioic acid (I) undergo a temperature-dependent reversible phase transition from monoclinic P21/c at a temperature higher than the critical temperature (Tc) 130 K to another monoclinic P21/c at temperature lower than Tc. The phase transition is of first order, involving a discontinuity and a tripling of the b-axis at Tc whereas the other unit cell parameters vary continuously. The transition is described by the phenomenological Landau theory. The crystal structure analyses for data collected at 297(2) K and 120.0(1) K show that there is half of a molecule of (I) in the asymmetric unit at 297(2) K whereas there are one and a half molecules of (I) in the asymmetric unit at 120.0(1) K. At both temperatures, 297(2) and 120.0(1) K, intermolecular O-H···O hydrogen bonds link the molecules of I into infinite 1D chains along [101] direction. However there are significantly more O-H···O hydrogen bonds presented in the 120.0(1) K polymorph, thereby indicating this phase transition is negotiated via hydrogen bonds. The relationship of the conformational changes and hydrogen bonding for these two polymorphs are explained in detail.
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 title compound, bis(2,4-dinitrophenolato-kappa2O,O')(1,4,7,10,13,16-hexaoxadecane-kappa6O)barium(II), [Ba(C6H3N2O5)2(C12H24O6)], is a 1:1 complex of barium(II)-2,4-dinitrophenolate and 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6). Its structure is located on a crystallographic inversion centre. The temperature dependence of the crystal structure has been studied. The monoclinic beta angle of the P2(1)/n space group increases with increasing temperature. The packing structure of the complex is stabilized by intermolecular C-H...O interactions.
The title compound, C20H28O3, known as 'trichodermaerin' [systematic name: (4E)-4,9,15,16,16-penta-methyl-6-oxa-tetra-cyclo-[10.3.1.0(1,10).0(5,9)]hexa-dec-4-ene-7,13-dione], is a diterpene lactone which was isolated from Trichoderma asperellum. The structure has a tetra-cycic 6-5-7-5 ring system, with the cyclo-hexa-none ring adopting a twisted half-chair conformation and the cyclo-pentane ring adopting a half-chair conformation, whereas the cyclo-heptene and tetra-hydro-furan-anone 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 inter-actions.
The asymmetric unit of the title hydrated salt, C22H25N2 (+)·C6H4ClO3S(-)·H2O, comprises two 2-[4-(di-ethyl-amino)-styr-yl]-1-methyl-quinolin-1-ium cations, two 4-chloro-benzene-sul-fon-ate anions and two solvent water mol-ecules. One ethyl group of both cations displays disorder over two positions in a 0.659 (2):0.341 (2) ratio in one mol-ecule 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 mol-ecules are linked into chains along the [010] direction by O-H⋯Osulfonate hydrogen bonds, together with weak C-H⋯Osulfonate and C-H⋯Cl inter-actions. The cations are stacked by π-π inter-actions, with centroid-centroid distances in the range 3.675 (2)-4.162 (3) Å.
There are two crystallograpically independent mol-ecules in the asymmetric unit of the title bis-chalcone derivative, C25H32N2O. Both mol-ecules are twisted with a dihedral angle between the two substituted benzene rings of 11.19 (16)° in one mol-ecule 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 mol-ecule, whereas the corresponding values are 8.42 (16) and 6.18 (16)° in the other. In the crystal, mol-ecules are arranged into chains along the c-axis direction. Adjacent chains are inter-linked by weak inter-molecular C-H⋯O inter-actions. The crystal is further stabilized by C-H⋯π inter-actions.
The asymmetric unit of the title salt, C36H32N2 (2+)·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-H⋯O inter-actions into chains along [010]. Adjacent chains are further arranged in an anti-parallel manner into sheets parallel to the bc plane. π-π inter-actions are observed involving the cations, with centroid-centroid distances of 3.7664 (8) and 3.8553 (8) Å.
The title compound crystallizes as a hemihydrate, C18H20N2O5·0.5H2O. The mol-ecule exists in an E conformation with respect to the C=N imine bond. The 4-meth-oxy-phenyl 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-meth-oxy-substituted ring. All meth-oxy substituents lie close to the plane of the attached benzene rings [the Cmeth-yl-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-H⋯O and O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions.
In the structure of the title salt, C20H20NO(+)·C6H4FO3S(-), the 4-(eth-oxy-phen-yl)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 eth-oxy 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⋯Osulfon-yl weak inter-actions. These chains are further connected into sheets parallel to (001) by C-H⋯Osulfon-yl weak inter-actions. The chains are also stacked along the a axis through π-π inter-actions 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 inter-actions are also present.
In the title hydrated salt, C15H16NO2 (+)·C6H4BrO3S(-)·H2O, the cation exists in an E conformation with respect to the ethenyl bond and is almost planar, with a dihedral angle of 2.62 (12)° between the planes of the pyridinium and benzene rings. The meth-oxy substituent deviates slightly from the plane of its attached benzene ring [Cmeth-yl-O-C-C torsion angle = -11.6 (6)°]. In the crystal, the cations, anion and water mol-ecules are linked together into chains along [010] by O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions. There is a short Br⋯O contact [3.029 (2) Å]. The crystal structure also features C-H⋯π inter-actions involving the benzene ring of the anion.
In the title mixed salt, 2C16H15N2 (+)·C6H4ClO3S(-)·NO3 (-), one of the cations shows whole mol-ecule disorder over two sets of sites in a 0.711 (7):0.289 (7) ratio. The 4-chorobenzenesulfon-ate 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 anti-parallel manner approximately along the a-axis direction and linked with the anions via N-H⋯O hydrogen bonds and C-H⋯O inter-actions, generating a three-dimensional network. Weak C-H⋯π and π-π inter-actions [with centroid-centroid distances of 3.561 (2)-3.969 (7) Å] are also observed.
The title compound, C15H15NO4S, was obtained by the condensation of 4-amino-aceto-phenone and 4-meth-oxy-benzene-sulfonyl chloride. The dihedral angle between the benzene rings is 86.56 (9)° and the mol-ecule has an approximate V-shaped conformation. The C atom of the meth-oxy group is roughly coplanar with its attached ring [deviation = 0.177 (3) Å], as is the methyl C atom of the acetyl group with its ring [deviation = 0.065 (2) Å]. An intra-molecular C-H⋯O inter-action generates an S(6) ring. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into [010] chains. Weak C-H⋯π inter-actions are also observed.
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 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.
There are two independent mol-ecules in the asymmetric unit of the title compound, C16H17NO4, with similar conformations but some differences in their bond angles. Each mol-ecule adopts a trans configuration with respect to the methyl-idene C=N bond and is twisted with a dihedral angle between the two substituted benzene rings of 80.52 (7)° in one mol-ecule and 83.53 (7)° in the other. All meth-oxy groups are approximately coplanar with the attached benzene rings, with Cmeth-yl-O-C-C torsion angles ranging from -6.7 (2) to 5.07 (19)°. In the crystal, independent mol-ecules are linked together by O-H⋯N and O-H⋯O hydrogen bonds and a π-π inter-action [centroid-centroid distance of 3.6030 (9) Å], forming a dimer. The dimers are further linked by weak C-H⋯O inter-actions and another π-π inter-action [centroid-centroid distance of 3.9452 (9) Å] into layers lying parallel to the ab plane.
In the title hydrated molecular salt, C22H25N2 (+)·C6H4FO3S(-)·H2O, the cation displays whole mol-ecule disorder over two sets of sites in a 0.780 (5):0.220 (5) ratio. The quinolinium ring system is essentially planar, with r.m.s. deviations of 0.0162 and 0.0381 Å for the major and minor disorder components, respectively. The dihedral angles between the mean plane of the quinolinium ring system and the benzene ring are 5.1 (3) and 7.7 (11)°, respectively, for the major and minor components in the cation. In the crystal, cations, anions and water mol-ecules are linked into chains along [010] by O-H⋯O hydrogen bonds and are further connected into a three-dimensional network by weak C-H⋯O and C-H⋯F inter-actions. In addition, π-π inter-actions with centroid-centroid distances of 3.634 (3), 3.702 (5) and 3.838 (5) Å are observed.
The title compound, C16H16N4O7, is close to being planar, with a dihedral angle of 3.15 (11)° between the benzene rings. The meth-oxy groups at the ortho- and para-positions of the 2,4,5-tri-meth-oxy-phenyl group are almost coplanar with the ring [deviations of the C atoms = 0.017 (2) and -0.025 (2) Å, respectively], whereas the meta-meth-oxy group deviates slightly [C-atom displacement = 0.162 (2) Å]. Both the ortho- and para-nitro groups are close to being coplanar with their attached ring [dihedral angles = 7.81 (12) and 8.56 (11)°, respectively]. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds involving the same H atom as the intra-molecular bond generate R 2 (2)(12) loops. The dimers are linked by weak C-H⋯O inter-actions into sheets parallel to the (10-4) plane and the sheets are stacked by π-π inter-actions, with a centroid-centroid distance of 3.5974 (14) Å.
The asymmetric unit of the title compound, C18H18ClN3OS·C2H5OH, comprises a pyrazoline derivative and an ethanol solvent mol-ecule. In the mol-ecule of the pyrazoline derivative, the pyrazole ring adopts an envelope conformation with the C atom bearing the eth-oxy-phenyl substituent as the flap. The dihedral angle between the benzene rings is 74.22 (7)°. The eth-oxy group is coplanar with the attached benzene ring [C-O-C-Cmeth-yl = 175.50 (11)° and r.m.s. deviation = 0.0459 (1) Å for the nine non-H atoms]. In the crystal, the pyrazoline mol-ecules are linked by N-H⋯Oeth-oxy hydrogen bonds into chains along the c axis and are further linked with the solvent ethanol mol-ecules by N-H⋯Oethanol and Oethanol-H⋯S hydrogen bonds. C-H⋯π inter-actions are also present.
The triclinic cell of the title compound contains 2C(12)H(24)N(+) x 2C(6)H(5)O(2)S(-) ion pairs that are linked by four hydrogen bonds [N...O = 2.728 (3) and 2.758 (3) A] across a centre of inversion.