In the title compound, C14H8N4O6, the benzoxazin-4-one fused-ring system (r.m.s. deviation = 0.018 Å) is coplanar with the attached benzene ring [dihedral angle = 0.81 (4)°], there being an intra-molecular N-H⋯N hydrogen bond between them. Each nitro group is twisted out of the plane of the attached benzene ring [O-N-C-C torsion angles = 167.94 (11) and 170.38 (11)°]. In the crystal, amine-nitro N-H⋯O hydrogen bonds lead to centrosymmetric dimeric aggregates that are connected into a three-dimensional architecture by oxazin-yl-nitro C-H⋯O and π-π inter-actions [inter-centroid distance between the oxazinyl and terminal benzene rings = 3.5069 (7) Å].
The crystal and mol-ecular structures of the title mol-ecular salts, C4H12NO+·C7H5N2O4 -, (I), C6H16NO+·C7H5N2O4 -, (II), and C4H12NO3 +·C7H5N2O4 -, (III), are described. The common feature of these salts is the presence of the 2-amino-4-nitro-benzoate anion, which exhibit non-chemically significant variations in the conformational relationships between the carboxyl-ate and nitro groups, and between these and the benzene rings they are connected to. The number of ammonium-N-H H atoms in the cations increases from one to three in (I) to (III), respectively, and this variation significantly influences the supra-molecular aggregation patterns in the respective crystals. Thus, a linear supra-molecular chain along [100] sustained by charge-assisted tertiary-ammonium-N-H⋯O(carboxyl-ate), hy-droxy-O-H⋯O(carboxyl-ate) and amino-N-H⋯O(carboxyl-ate) hydrogen-bonds is apparent in the crystal of (I). Chains are connected into a three-dimensional architecture by methyl-C-H⋯O(hy-droxy) and π-π inter-actions, the latter between benzene rings [inter-centroid separation = 3.5796 (10) Å]. In the crystal of (II), a supra-molecular tube propagating along [901] arises as a result of charge-assisted secondary-ammonium-N-H⋯O(carboxyl-ate) and hy-droxy-O-H⋯O(carboxyl-ate) hydrogen-bonding. These are connected by methyl-ene- and methyl-C-H⋯O(nitro) and π-π stacking between benzene rings [inter-centroid separation = 3.5226 (10) Å]. Finally, double-layers parallel to (100) sustained by charge-assisted ammonium-N-H⋯O(carboxyl-ate), ammonium-N-H⋯O(hy-droxy) and hy-droxy-O-H⋯O(carboxyl-ate) hydrogen-bonds are apparent in the crystal of (III). These are connected in a three-dimensional architecture by amine-N-H⋯O(nitro) hydrogen-bonds.
In the anion of the title salt hydrate, H5N2(+)·C7H5N2O4(-)·2H2O, the carboxyl-ate and nitro groups lie out of the plane of the benzene ring to which they are bound [dihedral angles = 18.80 (10) and 8.04 (9)°, respectively], and as these groups are conrotatory, the dihedral angle between them is 26.73 (15)°. An intra-molecular amino-N-H⋯O(carboxyl-ate) hydrogen bond is noted. The main feature of the crystal packing is the formation of a supra-molecular chain along the b axis, with a zigzag topology, sustained by charge-assisted water-O-H⋯O(carboxyl-ate) hydrogen bonds and comprising alternating twelve-membered {⋯OCO⋯HOH}2 and eight-membered {⋯O⋯HOH}2 synthons. Each ammonium-N-H atom forms a charge-assisted hydrogen bond to a water mol-ecule and, in addition, one of these forms a hydrogen bond with a nitro-O atom. The amine-N-H atoms form hydrogen bonds to carboxyl-ate-O and water-O atoms, and the amine N atom accepts a hydrogen bond from an amino-H atom. The hydrogen bonds lead to a three-dimensional architecture. An analysis of the Hirshfeld surface highlights the major contribution of O⋯H/H⋯O hydrogen bonding to the overall surface, i.e. 46.8%, compared with H⋯H contacts (32.4%).
The asymmetric unit of the title salt, C17H17F6N2O(+)·C10H8F3O3 (-), comprises two piperidin-1-ium cations and two carboxyl-ate anions. The cations, each having an l-shaped conformation owing to the near orthogonal relationship between the quinolinyl and piperidin-1-ium residues, are pseudo-enanti-omeric. The anions have the same absolute configuration but differ in the relative orientations of the carboxyl-ate, meth-oxy and benzene groups. Arguably, the most prominent difference between the anions occurs about the Cq-Om bond as seen in the Cc-Cq-Om-Cm torsion angles of -176.1 (3) and -67.1 (4)°, respectively (q = quaternary, m = meth-oxy and c = carboxyl-ate). The presence of Oh-H⋯Oc and Np-H⋯Oc hydrogen bonds leads to the formation of a supra-molecular chain along the a axis (h = hy-droxy and p = piperidin-1-ium); weak intra-molecular Np-H⋯Oh hydrogen bonds are also noted. Chains are connected into a three-dimensional architecture by C-H⋯F inter-actions. Based on a literature survey, related mol-ecules/cations adopt a uniform conformation in the solid state based on the letter L.
The crystal structures of two ammonium salts of 2-amino-4-nitro-benzoic acid are described, namely di-methyl-aza-nium 2-amino-4-nitro-benzoate, C2H8N+·C7H5N2O4-, (I), and di-butyl-aza-nium 2-amino-4-nitro-benzoate, C8H20N+·C7H5N2O4-, (II). The asymmetric unit of (I) comprises a single cation and a single anion. In the anion, small twists are noted for the carboxyl-ate and nitro groups from the ring to which they are connected, as indicated by the dihedral angles of 11.45 (13) and 3.71 (15)°, respectively; the dihedral angle between the substituents is 7.9 (2)°. The asymmetric unit of (II) comprises two independent pairs of cations and anions. In the cations, different conformations are noted in the side chains in that three chains have an all-trans [(+)-anti-periplanar] conformation, while one has a distinctive kink resulting in a (+)-synclinal conformation. The anions, again, exhibit twists with the dihedral angles between the carboxyl-ate and nitro groups and the ring being 12.73 (6) and 4.30 (10)°, respectively, for the first anion and 8.1 (4) and 12.6 (3)°, respectively, for the second. The difference between anions in (I) and (II) is that in the anions of (II), the terminal groups are conrotatory, forming dihedral angles of 17.02 (8) and 19.0 (5)°, respectively. In each independent anion of (I) and (II), an intra-molecular amino-N-H⋯O(carboxyl-ate) hydrogen bond is formed. In the crystal of (I), anions are linked into a jagged supra-molecular chain by charge-assisted amine-N-H⋯O(carboxyl-ate) hydrogen bonds and these are connected into layers via charge-assisted ammonium-N-H⋯O(carboxyl-ate) hydrogen bonds. The resulting layers stack along the a axis, being connected by nitro-N-O⋯π(arene) and methyl-C-H⋯O(nitro) inter-actions. In the crystal of (II), the anions are connected into four-ion aggregates by charge-assisted amino-N-H⋯O(carboxyl-ate) hydrogen bonding. The formation of ammonium-N-H⋯O(carboxyl-ate) hydrogen bonds, involving all ammonium-N-H and carboxyl-ate O atoms leads to a three-dimensional architecture; additional C-H⋯O(nitro) inter-actions contribute to the packing. The Hirshfeld surface analysis confirms the importance of the hydrogen bonding in both crystal structures. Indeed, O⋯H/H⋯O inter-actions contribute nearly 50% to the entire Hirshfeld surface in (I).
The asymmetric unit of the centrosymmetric title salt, C17H17F6N2O+·C2Cl3O2 -, comprises a single ion-pair. The hy-droxy-O and ammonium-N atoms lie to the same side of the cation, a disposition maintained by a charge-assisted ammonium-N-H⋯O(hy-droxy) hydrogen bond [the Oh-Cm-Cm-Na (h = hy-droxy, m = methine, a = ammonium) torsion angle is 58.90 (19)°]. The piperidin-1-ium group is approximately perpendicular to the quinolinyl residue [Cq-Cm-Cm-Na (q = quinolin-yl) is -178.90 (15)°] so that the cation, to a first approximation, has the shape of the letter L. The most prominent feature of the supra-molecular association in the crystal is the formation of chains along the a-axis direction, being stabilized by charge-assisted hydrogen-bonds. Thus, ammonium-N+-H⋯O-(carboxyl-ate) hydrogen bonds are formed whereby two ammonium cations bridge a pair of carboxyl-ate-O atoms, leading to eight-membered {⋯O⋯HNH}2 synthons. The resulting four-ion aggregates are linked into the supra-molecular chain via charge-assisted hydroxyl-O-H⋯O-(carboxyl-ate) hydrogen bonds. The connections between the chains, leading to a three-dimensional architecture, are of the type C-X⋯π, for X = Cl and F. The analysis of the calculated Hirshfeld surface points to the importance of X⋯H contacts to the surface (X = F, 25.4% and X = Cl, 19.7%) along with a significant contribution from O⋯H hydrogen-bonds (10.2%). Conversely, H⋯H contacts, at 12.4%, make a relatively small contribution to the surface.
The asymmetric unit of the centrosymmetric title salt solvate, 2C17H17F6N2O+· C4H4O4 2-·CH3CH2OH, (systematic name: 2-{[2,8-bis-(tri-fluoro-meth-yl)quinolin-4-yl](hy-droxy)meth-yl}piperidin-1-ium butane-dioate ethanol monosolvate) comprises two independent cations, with almost superimposable conformations and each approximating the shape of the letter L, a butane-dioate dianion with an all-trans conformation and an ethanol solvent mol-ecule. In the crystal, supra-molecular chains along the a-axis direction are sustained by charge-assisted hy-droxy-O-H⋯O(carboxyl-ate) and ammonium-N-H⋯O(carboxyl-ate) hydrogen bonds. These are connected into a layer via C-F⋯π(pyrid-yl) contacts and π-π stacking inter-actions between quinolinyl-C6 and -NC5 rings of the independent cations of the asymmetric unit [inter-centroid separations = 3.6784 (17) and 3.6866 (17) Å]. Layers stack along the c-axis direction with no directional inter-actions between them. The analysis of the calculated Hirshfeld surface reveals the significance of the fluorine atoms in surface contacts. Thus, by far the greatest contribution to the surface contacts, i.e. 41.2%, are of the type F⋯H/H⋯F and many of these occur in the inter-layer region. However, these contacts occur at separations beyond the sum of the van der Waals radii for these atoms. It is noted that H⋯H contacts contribute 29.8% to the overall surface, with smaller contributions from O⋯H/H⋯O (14.0%) and F⋯F (5.7%) contacts.
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.
In the title salt, C11H12ClN2O(+)·Cl(-), the ten non-H atoms comprising the quinolinium residue are coplanar (r.m.s. deviation = 0.041 Å) and the hy-droxy-ethyl group is approximately perpendicular to this plane [Cring-N-Cmethyl-ene-C torsion angle = -74.61 (18)°]. A supra-molecular chain aligned along [101] mediated by charge-assisted O/N-H⋯Cl(-) hydrogen bonds features in the crystal packing. Chains are connected into a three-dimensional architecture by C-H⋯O(hy-droxy) inter-actions.
The 21 non-H atoms of the title compound, C15H10Cl2N4, are almost planar (r.m.s. deviation = 0.032 Å); the conformation about the N=C bond [1.277 (6) Å] is E. In the crystal, zigzag supra-molecular chains along the c axis (glide symmetry) are formed via N-H⋯N hydrogen bonds. These associate along the b axis by π-π inter-actions between the fused and terminal benzene rings [inter-centroid distance = 3.602 (3) Å] so that layers form in the bc plane.
The asymmetric unit of the title co-crystal, C10H5BrO2·C14H8O4 [systematic name: 2-bromo-1,4-di-hydro-naphthalene-1,4-dione-1,8-dihy-droxy-9,10-di-hydro-anthracene-9,10-dione (1/1)], features one mol-ecule of each coformer. The 2-bromo-naphtho-quinone mol-ecule is almost planar [r.m.s deviation of the 13 non-H atoms = 0.060 Å, with the maximum deviations of 0.093 (1) and 0.099 (1) Å being for the Br atom and a carbonyl-O atom, respectively]. The 1,8-di-hydroxy-anthra-quinone mol-ecule is planar (r.m.s. deviation for the 18 non-H atoms is 0.022 Å) and features two intra-molecular hy-droxy-O-H⋯O(carbon-yl) hydrogen bonds. Dimeric aggregates of 1,8-di-hydroxy-anthra-quinone mol-ecules assemble through weak inter-molecular hy-droxy-O-H⋯O(carbon-yl) hydrogen bonds. The mol-ecular packing comprises stacks of mol-ecules of 2-bromo-naphtho-quinone and dimeric assembles of 1,8-di-hydroxy-anthra-quinone with the shortest π-π contact within a stack of 3.5760 (9) Å occurring between the different rings of 2-bromo-naphtho-quinone mol-ecules. The analysis of the Hirshfeld surface reveals the importance of the inter-actions just indicated but, also the contribution of additional C-H⋯O contacts as well as C=O⋯π inter-actions to the mol-ecular packing.
In the racemic title mol-ecular salt, C17H17F6N2O+·C2ClF2O3- (systematic name: 2-{[2,8-bis-(tri-fluoro-meth-yl)quinolin-4-yl](hy-droxy)meth-yl}piperidin-1-ium chloro-difluoro-acetate), the cation, which is protonated at the piperidine N atom, has the shape of the letter, L, with the piperidin-1-ium group being approximately orthogonal to the quinolinyl residue [the Cq-Cm-Cm-Na (q = quinolinyl; m = methine; a = ammonium) torsion angle is 177.79 (18)°]. An intra-molecular, charge-assisted ammonium-N-H⋯O(hydrox-yl) hydrogen bond ensures the hy-droxy-O and ammonium-N atoms lie to the same side of the mol-ecule [Oh-Cm-Cm-Na (h = hydrox-yl) = -59.7 (2)°]. In the crystal, charge-assisted hydroxyl-O-H⋯O-(carboxyl-ate) and ammonium-N+-H⋯O-(carboxyl-ate) hydrogen bonds generate a supra-molecular chain along [010]; the chain is consolidated by C-H⋯O inter-actions. Links between chains to form supra-molecular layers are of the type C-Cl⋯π(quinolinyl-C6) and the layers thus formed stack along the a-axis direction without directional inter-actions between them. The analysis of the calculated Hirshfeld surface points to the dominance of F⋯H contacts to the surface (40.8%) with significant contributions from F⋯F (10.5%) and C⋯F (7.0%) contacts.
The asymmetric unit of the title compound, C13H11N3O2S2, comprises two independent mol-ecules (A and B); the crystal structure was determined by employing synchrotron radiation. The mol-ecules exhibit essentially the same features with an almost planar benzo-thia-zole ring (r.m.s. deviation = 0.026 and 0.009 Å for A and B, respectively), which forms an inclined dihedral angle with the phenyl ring [28.3 (3) and 29.1 (3)°, respectively]. A difference between the mol-ecules is noted in a twist about the N-S bonds [the C-S-N-N torsion angles = -56.2 (5) and -68.8 (5)°, respectively], which leads to a minor difference in orientation of the phenyl rings. In the mol-ecular packing, A and B are linked into a supra-molecular dimer via pairwise hydrazinyl-N-H⋯N(thiazol-yl) hydrogen bonds. Hydrazinyl-N-H⋯O(sulfon-yl) hydrogen bonds between A mol-ecules assemble the dimers into chains along the a-axis direction, while links between centrosymmetrically related B mol-ecules, leading to eight-membered {⋯HNSO}2 synthons, link the mol-ecules along [001]. The result is an undulating supra-molecular layer. Layers stack along the b-axis direction with benzo-thia-zole-C-H⋯O(sulfon-yl) points of contact being evident. The analyses of the calculated Hirshfeld surfaces confirm the relevance of the above inter-molecular inter-actions, but also serve to further differentiate the weaker inter-molecular inter-actions formed by the independent mol-ecules, such as π-π inter-actions. This is also highlighted in distinctive energy frameworks calculated for the individual mol-ecules.
In the title carbohydrazide, C10H7N3O4S, the dihedral angle between the terminal five-membered rings is 27.4 (2)°, with these lying to the same side of the plane through the central CN2C(=O) atoms (r.m.s. deviation = 0.0403 Å), leading to a curved mol-ecule. The conformation about the C=N imine bond [1.281 (5) Å] is E, and the carbonyl O and amide H atoms are anti. In the crystal, N-H⋯O hydrogen bonds lead to supra-molecular chains, generated by a 41 screw-axis along the c direction. A three-dimensional architecture is consolidated by thienyl-C-H⋯O(nitro) and furanyl-C-H⋯O(nitro) inter-actions, as well as π-π inter-actions between the thienyl and furanyl rings [inter-centroid distance = 3.515 (2) Å]. These, and other, weak inter-molecular inter-actions, e.g. nitro-N-O⋯π(thien-yl), have been investigated by Hirshfeld surface analysis, which confirms the dominance of the conventional N-H⋯O hydrogen bonding to the overall mol-ecular packing.