Abbas Farhadikoutenaei

2-Amino-5-methyl­pyridinium 2-amino­benzoate

In the 2-aminobenzoate anion of the title salt, C6H9N2 +·C7H6NO2 −, an intramolecular N—H⋯O hydrogen bond is observed. The dihedral angle between the ring and the CO2 group is 8.41 (13)°. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms via a pair of N—H⋯O hydrogen bonds, forming an R 2 2(8) ring motif. The ion pairs are further connected via N—H⋯O hydrogen bonds, resulting in a donor–donor–acceptor–acceptor (DDAA) array of quadruple hydrogen bonds. The crystal structure also features a weak N—H⋯O hydrogen bond and a C—H⋯π interaction, resulting in a three-dimensional network.

2-Amino-5-methyl­pyridinium trifluoro­acetate

In the title salt, C6H9N2 +·C2F3O2 −, the F atoms of the anion are disordered over two sets of sites, with refined occupancies in a ratio of 0.505 (17):0.495 (17). In the crystal, cations and anions are linked via N—H⋯O hydrogen bonds, forming R 2 2(8) ring motifs. The ionic units are linked into a two-dimensional network parallel to (100) by N—H⋯O and weak C—H⋯O hydrogen bonds. The crystal structure is further stabilized by weak C—H⋯F hydrogen bonds, resulting in a three-dimensional network.

Ethyl 6-(4-methoxyphenyl)-2-oxo-4-phenylcyclohex-3-enecarboxylate

The asymmetric unit of the title compound, C22H22O4, consists of two independent molecules (A and B). The cyclohexene rings adopt slightly distorted sofa conformations in both molecules. The dihedral angles between the benzene rings are 74.16 (13) and 71.85 (13)° in molecules A and B, respectively. In the crystal, weak C—H⋯O hydrogen bonds link the molecules into a ribbon-like structure along the b axis. Weak C—H⋯π interactions are also observed.

2-Amino-5-methyl-pyridinium 3-chloro-benzoate.

The 3-chlorobenzoate anion of the title salt, C6H9N2 +·C7H4ClO2 −, is nearly planar with a dihedral angle of 2.44 (13)° between the benzene ring and the carboxylate group. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N—H⋯O hydrogen bonds with an R 2 2(8) ring motif, forming an approximately planar ion pair with a dihedral angle of 7.92 (5)° between the pyridinium and benzene rings. The ion pairs are further connected via N—H⋯O and C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane.

Ethyl 4-(4-methoxy­phen­yl)-2-oxo-6-phenyl­cyclo­hex-3-ene-1-carboxyl­ate

The asymmetric unit of the title compound, C22H22O4, consists of two independent molecules (A and B) which differ significantly in the orientations of ethyl carboxylate groups. The phenyl ring in molecule B is disordered over two orientations with occupancies of 0.55 (2) and 0.45 (2). The cyclohexenone ring of both molecules adopts an envelope conformation. The dihedral angle between the two aromatic rings is 81.12 (7)° in molecule A and 70.8 (3)° in molecule B [57.5 (4)° in the minor disorder component]. The crystal structure is stabilized by weak intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions.

2-Amino-5-methyl­pyridinium 2-hy­droxy-5-chloro­benzoate

In the 5-chlorosalicylate anion of the title salt, C6H9N2 +·C7H4ClO3 −, an intramolecular O—H⋯O hydrogen bond with an S(6) graph-set motif is observed and the dihedral angle between the benzene ring and the –CO2 group is 1.6 (6)°. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms via a pair of N—H⋯O hydrogen bonds, forming an R 2 2(8) ring motif. The crystal structure also features N—H⋯O and weak C—H⋯O interactions, resulting in a layer parallel to (10-1).

4,6-Dimeth-oxy-2-(methyl-sulfan-yl)pyrimidine-4-hy-droxy-benzoic acid (1/1).

The base molecule of the title co-crystal, C7H10N2O2S·C7H6O3, is essentially planar, with a maximum deviation of 0.0806 (14) Å for all non-H atoms. The acid molecule is also nearly planar, with a dihedral angle of 8.12 (14)° between the benzene ring and the carboxy group. In the crystal, the acid molecules form an inversion dimer through a pair of O—H⋯O hydrogen bonds with an R 2 2(8) ring motif. The pyrimidine molecules are linked on both sides of the dimer into a heterotetramer via O—H⋯N and C—H⋯O hydrogen bonds with R 2 2(8) ring motifs. The heterotetramers are further linked by weak C—H⋯O hydrogen bonds, forming a tape structure along [1-10].

2-Amino-5-methyl­pyridinium 6-oxo-1,6-dihydro­pyridine-2-carboxyl­ate

The anion of the title salt, C6H9N2 +·C6H4NO3 −, undergoes an enol-to-keto tautomerism during the crystallization. In the crystal structure, the cation and anion are held together by a relatively short N—H⋯O hydrogen bond, and the two anions are further connected to each other by a pair of N—H⋯O hydrogen bonds with an R 2 2(8) ring motif, thus forming a centrosymmetric 2 + 2 aggregate. The aggregates are further linked through weak N—H⋯O and C—H⋯O hydrogen bonds, resulting a three-dimensional network.

Bis(2,6-diamino-4-chloro-pyrimidin-1-ium) fumarate.

In the title salt, 2C4H6ClN4 +·C4H2O4 2−, the complete fumarate dianion is generated by crystallographic inversion symmetry. The cation is essentially planar, with a maximum deviation of 0.018 (1) Å. In the anion, the carboxylate group is twisted slightly away from the attached plane, the dihedral angle between the carboxylate and (E)-but-2-ene planes being 12.78 (13)°. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N—H⋯O hydrogen bonds, forming an R 2 2(8) ring motif. In addition, another type of R 2 2(8) motif is formed by centrosymmetrically related pyrimidinium cations via N—H⋯N hydrogen bonds. These two combined motifs form a heterotetramer. The crystal structure is further stabilized by stong N—H⋯O, N—H⋯Cl and weak C—H⋯O hydrogen bonds, resulting a three-dimensional network.

(2E)-3-(2-Fluoro-phen-yl)-1-(4-fluoro-phen-yl)prop-2-en-1-one.

In the title compouund, C15H10F2O, the molecule exists in an E conformation with respect to the C=C bond [1.3382 (16) Å]. The dihedral angle between the fluoro-substituted benzene rings is 6.80 (6)° and the whole molecule is roughly planar (r.m.s. deviation for the non-H atoms = 0.069 Å). In the crystal, molecules are linked by C—H⋯F and C—H⋯O interactions into sheets lying parallel to the bc plane.