(R)‐N‐[(R)‐1‐(2‐Hydroxy‐5‐methyl­phenyl)‐2‐phenyl­ethyl]‐2‐methyl‐1‐phenyl­propyl­ammonium chloride

In the title compound, C₂₅H₃₀NO⁺·Cl⁻, the mol­ecules are linked by a combination of inter­molecular N—H⋯Cl and O—H⋯Cl hydrogen bonds and intra­molecular N—H⋯O hydrogen bonds. The absolute configuration of the new stereogenic centre (the C atom adjacent to the N atom on the phenol side) is determined to have an R configuration.     

(R)‐4‐(4‐Fluoro­phenyl)‐1‐[2‐hydroxy‐2‐(3‐methyl‐1‐benzo­furan‐2‐yl)­ethyl]­piperazinium chloride propan‐1‐ol solvate

The title compound, C₂₁H₂₄FN₂O₂⁺·Cl⁻·C₃H₈O, is a potential drug designed as a hybrid compound with antihypertensive, antioxidant and β‐adrenolytic activity. The cation contains nearly planar benzo­furan and fluoro­phenyl ring systems, as well as a piperazine ring adopting an almost perfect chair conformation. The benzo­furan and piperazine moieties are connected by an ethyl chain, the moieties forming a dihedral angle of 163.12 (13)°. In the crystal structure, ions and propanol solvent mol­ecules are linked via N—H⋯Cl and O—H⋯Cl bonds into linear (010) chains.     

4‐Amino‐N‐isopropyl­benzamidinium chloride ethanol solvate

The title compound, C₁₀H₁₆N·Cl⁻·C₂H₆O, is an important intermediate in the convergent synthesis of amidine‐substituted polycyclic heterocycles, a class of compounds that shows significant anticancer activity. The molecule of (I) is not planar, having a dihedral angle of 25.00 (7)° between the aniline and amidine (–C—NH=C=NH₂) groups. The proton­ation of the amidine molecular fragment is accompanied by delocalized C—N bond distances of 1.320 (2) and 1.317 (2) Å. The cations and chloride anions are involved in a network of hydrogen bonds, resulting in the formation of infinite chains propagating along the b direction. The chains are further grouped within the ab plane, in such a way that the structure is segregated into layers dominated by hydro­phobic interactions involving N‐isopropyl residues and layers dominated by N—H⋯Cl [N⋯Cl = 3.275 (2)–3.596 (2) Å], O—H⋯Cl [O⋯Cl = 3.229 (3) Å] and N—H⋯O [N⋯O = 2.965 (3) Å] hydrogen bonds.     

N,N‐Di­methyl­anilinium 3‐cyano‐4‐(di­cyano­methyl­ene)‐5‐oxo‐4,5‐di­hydro‐1H‐pyrrol‐2‐olate

In the title compound, C₈H₁₂N⁺·C₈HN₄O₂⁻, the anion and cation lie on a crystallographic mirror plane and form planar ribbons via N—H⋯O [N⋯O = 2.933 (4) Å, H⋯O = 2.01 Å and N—H⋯O = 170°] and N—H⋯N [N⋯N = 3.016 (5) Å, H⋯N = 2.15 Å and N—H⋯N = 169°] hydrogen bonds. The ribbons are further linked via weak C—H⋯O and C—H⋯N hydrogen bonds. In adjacent planes, anions lie opposite cations; π–π interactions (separation a/2 = 3.520 Å) exist between the anions and the cations, and stacks are formed, running along the a axis. The cations are disordered over two interpenetrating sites, with occupancies of 0.833 (5) and 0.167 (5).     

Dichloro­(O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid‐κ2N,N′)copper(II)

In the title compound, [CuCl₂(C₉H₁₂N₂O)], the Cu^II atom is coordinated by two Cl⁻ anions and two N atoms of one O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid mol­ecule in a slightly distorted square‐planar geometry, with Cu—N distances of 2.0483 (17) and 1.9404 (18) Å, and Cu—Cl distances of 2.2805 (10) and 2.2275 (14) Å. In addition, each Cu^II atom is connected by one Cl⁻ anion and the Cu^II atom from a neighbouring mol­ecule, with Cu⋯Cl and Cu⋯Cu distances of 2.9098 (13) and 3.4022 (12) Å, respectively, and, therefore, a centrosymmetric dimer is formed. Adjacent mol­ecular dimers are connected by π–π stacking inter­actions between pyridine rings to form a zigzag mol­ecular chain. The mol­ecular chains are also enforced by N—H⋯Cl and C—H⋯Cl inter­actions.     

π‐Stacked hydrogen‐bonded dimers in 2‐(2‐nitro­phenyl­amino­carbonyl)­benzoic acid,and hydrogen‐bonded sheets in orthorhombic and monoclinic polymorphs of 2‐(4‐nitro­phenyl­amino­carbonyl)­benzoic acid

Molecules of 2‐(2‐nitrophenylaminocarbonyl)benzoic acid, C₁₄H₁₀N₂O₅, are linked into centrosymmetric R(8) dimers by a single O—H⋯O hydrogen bond [H⋯O = 1.78 Å, O⋯O = 2.623 (2) Å and O—H⋯O = 178°] and these dimers are linked into sheets by a single aromatic π–π stacking interaction. The isomeric compound 2‐(4‐nitrophenylaminocarbonyl)benzoic acid crystallizes in two polymorphic forms. In the orthorhombic form (space group P2₁2₁2₁ with Z′ = 1, crystallized from ethanol), the mol­ecules are linked into sheets of R(22) rings by a combination of one N—H⋯O hydrogen bond [H⋯O = 1.96 Å, N⋯O = 2.833 (3) Å and N—H⋯O = 171°] and one O—H⋯O hydrogen bond [H⋯O = 1.78 Å, O⋯O = 2.614 (3) Å and O—H⋯O = 173°]. In the monoclinic form (space group P2₁/n with Z′ = 2, crystallized from acetone), the mol­ecules are linked by a combination of two N—H⋯O hydrogen bonds [H⋯O = 2.09 and 2.16 Å, N⋯O = 2.873 (4) and 2.902 (3) Å, and N—H⋯O = 147 and 141°] and two O—H⋯O hydrogen bonds [H⋯O = 1.84 and 1.83 Å, O⋯O = 2.664 (3) and 2.666 (3) Å, and O—H⋯O = 166 and 174°] into sheets of some complexity. These sheets are linked into a three‐dimensional framework by a single C—H⋯O hydrogen bond [H⋯O = 2.45 Å, C⋯O = 3.355 (4) Å and C—­H⋯O = 160°].     

3,5‐Bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐piperidone and 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐oxopiperidinium chloride: potential biophotonic materials

In the title compound 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐piperidone, C₂₂H₂₃NO₃, (I), the central heterocyclic ring adopts a flattened boat conformation, while in the related salt 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐oxopiperidin­ium chloride, C₂₂H₂₄NO₃⁺·Cl⁻, (II), the ring exhibits a `sofa' conformation in which the N atom deviates from the planar fragment. The pendant benzene rings are twisted from the heterocyclic ring planes in both mol­ecules in the same direction, the range of dihedral angles between the ring planes being 24.5 (2)–32.7 (2)°. The dominant packing motif in (I) involves centrosymmetric dimers bound by weak intermolecular C—H⋯O hydrogen bonds. In (II), cations and anions are linked by strong N—H⋯Cl hydrogen bonds, while weak C—H⋯O and C—H⋯Cl hydrogen bonds link the cations and anions into a three‐dimensional framework.     

2,2′‐(Iminodimethylene)bis(1H‐benzimidazolium)(1+) chloride

The title compound, C₁₆H₁₆N₅⁺·Cl⁻ (nbbH⁺·Cl⁻), displays N—H⋯N, N—H⋯Cl and π–π inter­actions in the crystal packing. The Cl⁻ anion is chelated by the nbbH⁺ cation via two N—H⋯Cl hydrogen bonds. Inter‐ion N—H⋯N and N—H⋯Cl hydrogen bonds link ions related by 2₁ screw axes into chains along the c axis. These chains are further linked by glide‐plane operations to generate a three‐dimensional network, which is additionally stabilized by inter­chain π–π inter­actions.     

(R)‐1‐Phenyl­ethyl­ammonium 6‐amino‐5‐nitro­pyrimidine‐2,4(1H,3H)‐dionate (R)‐1‐phenyl­ethyl­amine hemisolvate: hydrogen‐bonded sheets of ions with pendent solvent mol­ecules

In the title compound, 2C₈H₁₂N⁺·2C₄H₃N₄O₄⁻·C₈H₁₁N, the anions are linked by paired N—H⋯N hydrogen bonds [H⋯N = 2.07 and 2.11 Å, N⋯N = 2.942 (3) and 2.978 (3) Å and N—H⋯N = 173 and 170°] and by paired N—H⋯O hydrogen bonds [H⋯O = 1.98 and 2.05 Å, N⋯O = 2.855 (3) and 2.917 (3) Å, and N—H⋯O = 173 and 167°] into chains of rings. These chains are linked into sheets by further N—H⋯O hydrogen bonds in which all of the donors are provided by the cations [H⋯O = 1.83–2.17 Å, N⋯O = 2.747 (3)–2.965 (3) Å and N—H⋯O = 141–168°]. The neutral amine molecule is pendent from the sheet and is linked to it by a single N—H⋯N hydrogen bond [H⋯N = 2.00 Å, N⋯N = 2.901 (3) Å and N—H⋯N = 175°].     

(2‐Hydroxy­ethyl)­hydrazinium(2+) dichloride

The crystal structure of the title compound, C₂H₁₀N₂O²⁺·2Cl⁻, is built up from one 2‐hydroxy­ethyl­hydrazinium(2+) cation and two Cl⁻ anions. The mol­ecular structure is stabilized by O—H⋯Cl and N—H⋯Cl hydrogen bonds. The crystal structure is stabilized by one N—H⋯O and three N—H⋯Cl inter­actions, and the three‐dimensional network of hydrogen bonds stabilizes the crystal packing. All five hydrazinium H atoms are involved in hydrogen bonds to Cl⁻ anions. The Cl⋯H contact distances range from 2.122 (15) to 2.809 (14) Å.     

5‐Amino‐3‐tert‐butyl‐1‐(4‐nitro­phen­yl)‐1H‐pyrazole forms hydrogen‐bonded sheets of alternating R(20) and R(32) rings

Molecules of the title compound, C₁₃H₁₆N₄O₂, are linked by one N—H⋯O hydrogen bond [H⋯O = 2.47 Å, N⋯O = 3.326 (2) Å and N—H⋯O = 166°] and one N—H⋯N hydrogen bond [H⋯N = 2.19 Å, N⋯N = 3.063 (2) Å and N—H⋯N = 173°] into sheets containing alternating (20) and (32) rings, both types of which are centrosymmetric.     

Three‐dimensional hydrogen‐bonding supramolecular architecture of 2‐(3‐pyridinio)‐5‐(3‐pyridyl)‐1,3,4‐oxa­diazole perchlorate

In the crystal structure of the title compound, C₁₂H₉N₄O⁺·ClO₄⁻, the protonated cation adopts a cis‐I conformation and approximately planar geometry. Each perchlorate anion acts as the acceptor of three C—H⋯O weak interactions, which, together with N—H⋯N and C—H⋯N hydrogen bonds between the protonated cations, extend this structure into a three‐dimensional hydrogen‐bonded network.     

2,5‐Dicarboxy­anilinium chloride monohydrate

The title compound, C₈H₈NO₄⁺·Cl⁻·H₂O, is the chloro­hydrated form of 2‐amino­benzene‐1,4‐dicarboxylic acid, the basic crystal structure of which is still not known. Mol­ecules are linked by classical N—H⋯O, O—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds, mainly along the mol­ecular plane, into sheets built by unusual R₆⁴(26), R₆⁴(22) and R₄³(22) rings. The stacking between layers is stabilized by another N—H⋯Cl hydrogen bond and by π–π inter­actions between aromatic rings facing each other.     

N1‐(4‐tert‐Butyl­phenyl)‐N2‐hydroxy‐α‐oxo‐α‐phenyl­acet­amidine and N2‐hydroxy‐N1‐(4‐nitro­phenyl)‐α‐oxo‐α‐phenyl­acet­amidine hemihydrate

In the title compounds, C₁₈H₂₀N₂O₂, (I), and C₁₄H₁₁N₃O₄·0.5H₂O, (II), respectively, the oxime groups have an E configuration. In (I), the mol­ecules exist as polymers bound by intermolecular C—H⋯O and O—H⋯N hydrogen bonds around inversion centres. In (II), intermolecular OW—H⋯N, OW—H⋯O and O—H⋯OW interactions stabilize the molecular packing.     

trans‐Bis[3,5‐bis­(trifluoro­meth­yl)‐1H‐pyrazole‐κN2]dichloro­palladium(II) monohydrate

The palladium(II) center in the title compound, trans‐[PdCl₂(C₅H₂F₆N₂)₂]·H₂O, possesses a distorted square‐planar geometry. The NH groups are positioned on the same side of the PdN₂Cl₂ coordination plane. Four symmetry‐independent strong hydrogen bonds of three types (N—H⋯Cl, N—H⋯Cl and O—H⋯Cl) hold the structure together.     

Bilayers in 4‐iodo‐N‐(2‐iodo‐4‐nitrophenyl)benzamide generated by a combination of an N—H⋯O=C hydrogen bond and two independent iodo–nitro interactions

Molecules of the title compound, C₁₃H₈I₂N₂O₃, are linked into C(4) chains by a single N—H⋯O=C hydrogen bond [H⋯O = 2.10 Å, N⋯O = 2.832 (5) Å and N—H⋯O = 140°]. Two independent two‐centre iodo–nitro interactions, both involving the same O atom but different I atoms [I⋯O = 3.205 (3) and 3.400 (3) Å, and C—I⋯O = 160.4 (2) and 155.7 (2)°], link the hydrogen‐bonded chains into bilayers.     

1‐(4‐Chloro­phenyl)‐2‐methyl‐4‐nitro‐5‐(1‐piperidyl)‐1H‐imidazole

The only specific inter­actions that influence the crystal packing of the title compound, C₁₅H₁₇ClN₄O₂, are weak C—H⋯N and C—H⋯Cl hydrogen bonds, even though there is a possibility of, for example, π–π stacking or halogen bonding. The dihedral angle between the mean planes of the imidazole and benzene rings is 59.82 (5)°. The length of the C—N bond connecting the imidazole and piperidine fragments is correlated with the degree of pyramidalization of the piperidine N atom.     

N‐(2,4‐Dimethoxy­benzyl­idene­amino)­guanidinium dihydrogenphosphate

In the asymmetric unit of the title compound, C₁₀H₁₅N₄O₂⁺·H₂PO₄⁻, there are two protonated amino­guanidinium cations and two dihydrogenphosphate anions. The positive charge on the protonated amidine group is delocalized over the three C—N bonds in a manner similar to that found in guanidinium salts. The amino­guanidinium cations are found to be the E‐isomer structures. Intra­molecular inter­actions of the N—H⋯N type are observed, leading to the formation of five‐membered rings. Extensive networks of O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds stabilize the three‐dimensional network. In the crystal structure, π–π inter­actions between the benzene rings, with a distance of 3.778 (2) Å between the ring centroids, also affect the packing of the mol­ecules.     

N‐Cyclo­hexyl‐2‐[5‐(4‐pyridyl)‐4‐(p‐tolyl)‐4H‐1,2,4‐triazol‐3‐yl­sulfanyl]­acetamide dihydrate

In the title compound, C₂₂H₂₅N₅OS·2H₂O, the mol­ecules are stacked in columns running along the b axis. In this arrangemant, the mol­ecules are linked to each other by a combination of one two‐centre N—H⋯O hydrogen bond and four two‐centre O—H⋯O hydrogen bonds containing two types of ring motif, viz.R₄⁴(10) and R₃³(11). In the crystal structure, centrosymmetric π–π inter­actions between the triazole rings, with a distance of 3.691 (2) Å between the ring centroids, also affect the packing of the mol­ecules.     

Supramolecular structures of three isomeric 4‐(methyl­phenylamino)­pyridine‐3‐sulfonamides

The structures of the three title isomers, namely 4‐(2‐methyl­anilino)pyridine‐3‐sulfonamide, (I), 4‐(3‐methyl­anilino)pyridine‐3‐sulfonamide, (II), and 4‐(4‐methyl­anilino)pyridine‐3‐sulfonamide, (III), all C₁₂H₁₃N₃O₂S, differ in their hydrogen‐bonding arrangements. In all three mol­ecules, the conformation of the 4‐amino­pyridine‐3‐sulfon­amide moiety is conserved by an intra­molecular N—H⋯O hydrogen bond and a C—H⋯O inter­action. In the supra­mol­ecular structures of all three isomers, similar C(6) chains are formed via inter­molecular N—H⋯N hydrogen bonds. N—H⋯O hydrogen bonds lead to C(4) chains in (I), and to R₂²(8) centrosymmetric dimers in (II) and (III). In each isomer, the overall effect of all hydrogen bonds is to form layer structures.