In the title salt, C5H7N2
−, 2-aminopyridine and 1-phenylcyclopropane-1-carboxylic acid crystallize together, forming a 2-aminopyridinium–carboxylate supramolecular heterosynthon involving two N—H⋯O hydrogen bonds, which in turn dimerizes to form a four-component supramolecular unit also sustained by N—H⋯O hydrogen bonding. A C—H⋯π interaction between a pyridine C—H group and the centroid of the phenyl ring of the anion further stabilizes the four-component supramolecular unit. The overall crystal packing also features C—H⋯O interactions.
In the title compound, C26H21F6NO5, the dihedral angle between the cyclopropane ring plane and the vinyl group plane is 79.3 (3)°. The dihedral angle between the benzene and phenyl ring planes in the phenoxybenzyl group is 82.7 (1)°. In the crystal structure, weak intermolecular C—H⋯π interactions and C—H⋯F hydrogen bonds contribute to the stabilization of the packing.
In the structure of the title compound, C5H7N2
−, the cis anions associate through head-to-tail carboxylic acid–carboxyl O—H⋯O hydrogen bonds [graph set C(7)], forming chains which extend along c and are interlinked through the carboxyl groups, forming cyclic R
2(8) associations with the pyridinium and an amine H-atom donor of the cation. Further amine–carboxyl N—H⋯O interactions form enlarged centrosymmetric rings [graph set R
4(18)] and extensions down b, giving a three-dimensional structure.
In the crystal structure of the title molecular adduct, C9H7N·C8H12O4, the two species are linked through a carboxylic acid–isoquinoline O—H⋯N hydrogen bond. These molecular pairs then inter-associate through the second acid group of the cis-cyclohexane-1,2-dicarboxylic acid molecules, forming a classic centrosymmetric cyclic head-to-head carboxylic acid–carboxyl O—H⋯O hydrogen-bonding association [graph-set R
2(8)], giving a zero-dimensional (cluster) structure, consisting of two of each species.
In the title racemic salt, C6H13N2O+·C8H11O4
−, formed from the reaction of cis-cyclohexane-1,2-dicarboxylic anhydride with isonipecotamide, the cations are linked into duplex chain substructures through both centrosymmetric cyclic head-to-head ‘amide motif’ hydrogen-bonding associations [graph set R
2(8)] and ‘side-by-side’ R
2(14) associations. The anions are incorporated into the chains through cyclic R
3(10) interactions involving amide and piperidinium N—H⋯Ocarboxyl hydrogen bonds which, together with inter-anion carboxylic acid O—H⋯Ocarboxyl hydrogen bonds, give a two-dimensional layered structure extending along (011).
In the title compound, C15H14Cl2F3NO, synthesized by the reaction of 3-[(E)-2-chloro-3,3,3-trifluoroprop-1-enyl]-2,2-dimethylcyclopropanecarboxylic acid and 2-chloroaniline, the aromatic ring makes a dihedral angle of 76.7 (3)° with the plane of the cyclopropane ring. In the crystal, intermolecular N—H⋯O hydrogen bonds link the molecules into chains running along the b axis.
In the crystal structure of the title solvated molecular salt, C3H12N2
2−·C2H6OS, two amine groups of propane-1,3-diamine (pda) are protonated and two carboxylic acid groups of pyridine-2,5-dicarboxylic acid (2,5-pydcH2) are deprotonated. The crystal packing features N—H⋯O hydrogen bonds and weak C—H⋯O intermolecular interactions.
In the title salt C7H10NO+·C8H3Cl2O4
− the benzene rings of the cation and anion are essentially parallel [inter-ring dihedral angle 4.8 (2)°]. In the anion the carboxylic acid and carboxylate groups make dihedral angles of 19.0 (2) and 79.5 (2)°, respectively, with the benzene ring. Aminium N—H⋯O, carboxylic acid O—H⋯O and weak aromatic C—H⋯O hydrogen-bonding associations with carboxyl O-atom acceptors together with cation–anion π–π ring interactions [minimum ring centroid separation = 3.734 (3) Å] give rise to a sheet structure lying parallel to (001).
In the zwitterionic title compound, C17H11NO5, the dihedral angle between the two aromatic rings is 76.90 (7)°. The dihedral angles between the carboxyl groups and the benzene ring are 64.02 (9) and 21.67 (9)°, the larger angle being associated with an intramolecular N—H⋯Ocarboxyl hydrogen bond, resulting from proton transfer from the carboxylic acid group to the quinoline N atom and giving an S(9) ring motif. In the crystal, molecules are connected by O—H⋯O hydrogen bonds into chains extending along the b-axis direction. An overall two-dimensional network structure is formed through π–π interactions between the quinoline rings [minimum ring-centroid separation = 3.6068 (6) Å].
The complete molecule of the title compound, C24H32N2O4, is generated by a crystallographic inversion center. The 1,2-diethylhydrazine moiety is nearly planar, with a maximum deviation of 0.024 (1) Å, and is inclined at a dihedral angle of 54.20 (4)° with the phenyl ring. In the crystal,  chains are formed, with adjacent molecules in the chain linked by pair of intermolecular N—H⋯O hydrogen bonds, generating R
2(10) ring motifs. Intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions are also observed.
In the title salt, C12H11N2O2
+·C7H5O6S−, the dihedral angle between the benzene and pyridine rings in the 4-(4-nitrobenzyl)pyridinium cation is 82.7 (2)°. Within the anion there is an intramolecular hydroxy-O—H⋯O(carboxylic acid) bond. In the crystal, the cation forms a single N+—H⋯Osulfonate hydrogen bond with the anion. These cation–anion pairs interact through duplex anion carboxylic acid O—H⋯Osulfonate hydrogen bonds, giving a centrosymmetric cyclic association [graph set R
2(16)]. The crystals studied were non-merohedrally twinned.
In the asymmetric unit of the title co-crystal, C12H14N4O2S·C7H5NO4, the sulfamethazine and 2-nitrobenzoic acid molecules form a heterodimer through intermolecular amide–carboxylic acid N—H⋯O and carboxylic acid–pyrimidine O—H⋯N hydrogen-bond pairs, giving a cyclic motif [graph set R
2(8)]. The dihedral angle between the two aromatic ring systems in the sulfamethazine molecule is 88.96 (18)° and the nitro group of the acid is 50% rotationally disordered. Secondary aniline N—H⋯Osulfone hydrogen-bonding associations give a two-dimensional structure lying parallel to the ab plane.
In the title compound, C18H21N3O6, a pyrimidine derivative, the dihedral angle between the benzene and pyrimidine rings is 52.26 (12)°. The carboxylate unit is twisted with respect to the pyrimidine ring, making a dihedral angle of 12.33 (7)°. In the crystal, molecules are linked by a pair of O—H⋯O hydrogen bonds, forming an inversion dimer. The dimers are stacked into columns along the b axis through weak C—H⋯O interactions.
The title compound, C16H17ClF3NO2, was synthesized from 3-[(E)-2-chloro-3,3,3-trifluoroprop-1-enyl]-2,2-dimethylcyclopropanecarboxylic acid and 3-methoxybenzenamine. The propenyl and carboxamide substituents lie on the same side of the cyclopropane ring plane, with the two methyl substituents on either side of the plane. The benzene ring makes a dihedral angle of 76.4 (3)° with the plane of the cyclopropane ring. The crystal structure involves intermolecular N—H⋯O hydrogen bonds.
There are two molecules in the asymmetric unit of the title compound, C16H17ClF3NO. The benzene ring in each molecule makes a dihedral angle of 66.6 (3)° [116.3 (4)° in the second molecule] with the plane of the cyclopropane ring. The F atoms of the CF3 groups are disordered equally over two positions. The amide hydrogen is linked with the amide oxygen in another molecule by an intermolecular N—H⋯O hydrogen bond. The packing can be described as a dimeric arrangement of molecules linked through N—H⋯O hydrogen bonds.
In the title compound, C13H10O4, an analog of acetylsalicylic acid, the naphthalene unit is twisted slightly due to ortho disubstitution [dihedral angle between conjugated rings system in the naphthalene unit = 2.0 (2)°]. The mean planes of the carboxylic and ester groups are almost coplanar and perpendicular, respectively, to the mean plane of the conjugated aromatic system, making dihedral angles of 8.9 (3) and 89.3 (1)°. In the crystal, molecules are paired through their carboxylic groups by the typical centrosymmetric O—H⋯O interactions with R
2(8) hydrogen-bond motifs. In addition, several weak C—H⋯O intermolecular contacts are also observed. Finally, the molecules are stacked along crystallographic  and  directions.
The title Schiff base compound, C21H26N2O4, is a second triclinic polymorph of a previously reported room-temperature structure [Jia (2009 ▶). Acta Cryst. E65, o646]. Strong intramolecular O—H⋯N hydrogen bonds generate S(6) ring motifs. Intermolecular C—H⋯O interactions link neighbouring molecules into dimers with an R
2(16) ring motif. The mean planes of the two benzene rings are almost perpendicular to each other, making a dihedral angle of 88.24 (5)°. An interesting feature of the crystal structure is the intermolecular short C⋯O [3.1878 (13) Å] contact which is shorter than the sum of the van der Waals radii of the relevant atoms. The crystal structure is further stabilized by intermolecular C—H⋯π and π–π interactions [centroid–centroid distance = 3.7414 (6) Å]. The structure has a stereogenic centre but the space group is centrosymmetric, so the molecule exists as a racemate.
In the title compound, C24H23FN2O3, the cyclohexene ring adopts a screw-boat conformation. The fluorobenzene ring attached to the cyclohexene ring and the phenyl ring attached to the indazole moiety are inclined to one another by 57.77 (13)°. In the crystal, molecules are linked by O—H⋯N and C—H⋯O hydrogen bonds, forming chains with C(5) and C(10) graph-set motifs. There are also C—H⋯π interactions present. The isopropoxycarbonyl group undergoes considerable thermal motion.
In the title molecule, C15H11N3, the dihedral angle between the benzene ring and the fused pyrrole ring is 1.07 (5)°. The cyclohexene ring adopts an envelope conformation: the dicyanomethylene group at position 1 has a coplanar orientation. An intramolecular N—H⋯N hydrogen bond generates an S(7) ring motif. Intermolecular N—H⋯N hydrogen bonds form an R
2(14) ring in the crystal. A C—H⋯π interaction involving the benzene ring is also found in the structure.
The title compound, C17H16Cl2N2O2, assumes a V-shape configuration with a dihedral angle between the two halves of the molecule of 79.60 (4)°. The asymmetric unit comprises one half-molecule with a crystallographic twofold rotation axis passing through the central C atom. There are weak intermolecular π–π stacking interactions between neighbouring benzene rings with intermolecular plane-to-plane distances of 3.277 (6) and 3.465 (5) Å along the a and c axes, respectively. In the crystal structure, weak intermolecular C—H⋯O bonds link each molecule to four others to form an infinite three-dimensional network.
In the crystal structure of the title compound, C19H20N2O3·C3H6O, molecules are linked into inversion dimers with an R
2(12) motif by pairs of N—H⋯N hydrogen bonds. These dimers are further connected into chains running along the a axis by N—H⋯O hydrogen bonds. C—H⋯N and C—H⋯π interactions also feature in the packing. The cyclohexene ring adopts nearly an envelope conformation [puckering parameters are Q
T = 0.456 (2) Å, θ = 54.6 (3)° and ϕ = 225.2 (3)°].
In the title compound, C10H15NO5, the five-membered cyclopentane ring has an envelope conformation, with four atoms lying in a plane (mean deviation = 0.0213 Å), while the fifth atom deviates from this plane by 0.626 (2) Å. A three-dimensional structure is formed through N—H⋯O and O—H⋯O hydrogen bonds between the amide and carboxylic acid groups and both carboxylic acid and amide O-atom acceptors.
In the title compound, C16H20O5, the dihedral angle between the planar rings, viz. benzene and cyclopropane, is 52.1 (2)°. Molecules are connected in the crystal via weak intermolecular C—H⋯O hydrogen bonds, forming chains in the  direction.
The title compound, C15H21NO4S, crystallized with two independent molecules in the asymmetric unit in which the dihedral angles between the mean planes of the benzene and cyclohexane rings are 78.3 (2) and 67.6 (2)°. The substituents of the cyclohexyl rings are in equatorial orientations. In the crystal, both molecules form R
2(6) carboxylic acid inversion dimers via pairs of O—H⋯O hydrogen bonds. Further N—H⋯O and C—H⋯O interactions generate a three-dimensional network.
In the title compound, C16H13N3, the cyclohexene ring adopts a sofa conformation. An intramolecular N—H⋯N hydrogen bond generates an S(7) ring motif. In the crystal, the molecules are linked by pairs of N—H⋯N interactions, forming centrosymmetric dimers with an R