Trimethyl[3‐methyl‐1‐(o‐tolenesulfonyl)indol‐2‐ylmethyl]ammonium iodide and benzyl[3‐bromo‐1‐(phenylsulfonyl)indol‐2‐ylmethyl]tolylamine

The title compounds, C₂₀H₂₅N₂O₂S⁺·I^?, (I), and C₂₉H₂₅BrN₂O₂S, (II), respectively, both crystallize in space group P. The pyrrole ring subtends an angle with the sulfonyl group of 33.6° in (I) and 21.5° in (II). The phenyl ring of the sulfonyl substituent makes a dihedral angle with the best plane of the indole moiety of 81.6° in (I) and 67.2° in (II). The lengthening or shortening of the C—N bond distances in both compounds is due to the electron‐withdrawing character of the phenyl­sulfonyl group. The S atoms are in distorted tetrahedral configurations. The molecular structures are stabilized by C—H?O and C—H?I interactions in (I), and by C—H?O and C—H?N interactions in (II).     

Hydro­gen‐bonded adducts of ferrocene‐1,1′‐diyl­bis­(di­phenyl­methanol): a finite cyclic 1:1 adduct with 2,2′‐dipyridyl­amine

In ferrocene‐1,1′‐diyl­bis­(di­phenyl­methanol)–2,2′‐dipyridyl­amine (1/1), [Fe(C₁₈H₁₅O)₂]·C₁₀H₉N₃, (I), there is an intramolecular O—H?O hydrogen bond [H?O 2.03 Å, O?O 2.775 (2) Å and O—H?O 147°] in the ferrocenediol component, and the two neutral molecular components are linked by one O—H?N hydrogen bond [H?N 1.96 Å, O?N 2.755 (2) Å and O—H?N, 157°] and one N—H?O hydrogen bond [H?O 2.26 Å, N?O 3.112 (2) Å and N—H?O 164°] forming a cyclic R(8) motif. One of the pyridyl N atoms plays no part in the intermolecular hydrogen bonding, but participates in a short intramolecular C—H?N contact [H?N 2.31 Å, C?N 2.922 (2) Å and C—H?N 122°].     

5‐(2‐Chloro­phenyl­diazenyl)­salicyl­aldehyde and 4‐(2‐chloro­phenyl­diazenyl)‐2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}cyclo­hexa‐3,5‐dien‐1(2H)‐one

The mol­ecule of the former title compound, C₁₃H₉ClN₂O₂, (I), is nearly planar, with an intramolecular O⋯O hydrogen bond of 2.692 (2) Å. The latter title compound, C₁₇H₁₈ClN₃O₄, (II), exists in the keto–amine tautomeric form, with a strong intramolecular hydrogen bond of 2.640 (2) Å between the O and N atoms, the H atom being bonded to the N atom. The azo­benzene moieties of both mol­ecules have trans configurations, and the dihedral angle between the planes of the two aromatic rings is 4.1 (1)° in (I) and 9.9 (1)° in (II). The N—H⋯O hydrogen‐bonded rings are almost planar and coupled with the cyclo­hexa­diene rings in (II).     

Three N2‐benzoyl­oxybenz­amidines: sheet structures built from hard and soft hydrogen bonds and aromatic π–π stacking interactions

Molecules of the title compounds N²‐(benzoyl­oxy)­benz­ami­dine, C₁₄H₁₂N₂O₂, (I), N²‐(2‐hydroxy­benzoyl­oxy)­benz­ami­dine, C₁₄H₁₂N₂O₃, (II), and N²‐benzoyloxy‐2‐hydroxybenzamidine, C₁₄H₁₂N₂O₃, (III), all have extended chain conformations, with the aryl groups remote from one another. In (I), the mol­ecules are linked into chains by a single N—H⋯N hydrogen bond [H⋯N = 2.15 Å, N⋯N = 3.029 (2) Å and N—H⋯N = 153°] and these chains are linked into sheets by means of aromatic π–π stacking interactions. There is one intramolecular O—H⋯O hydrogen bond in (II), and a combination of one three‐centre N—H⋯(N,O) hydrogen bond [H⋯N = 2.46 Å, H⋯O = 2.31 Å, N⋯N = 3.190 (2) Å, N⋯O = 3.146 (2) Å, N—H⋯N = 138° and N—H⋯O = 154°] and one two‐centre C—H⋯O hydrogen bond [H⋯O = 2.46 Å, C⋯O = 3.405 (2) Å and C—H⋯O = 173°] links the mol­ecules into sheets. In (III), an intramolecular O—H⋯N hydrogen bond and two N—H⋯O hydrogen bonds [H⋯O = 2.26 and 2.10 Å, N⋯O = 2.975 (2) and 2.954 (2) Å, and N—H⋯O = 138 and 163°] link the molecules into sheets.     

1:1 Complex of 4‐nitro­benzoic acid and 4‐nitro­pyridine N‐oxide

In the title co‐crystal, C₇H₅NO₄·C₅H₄N₂O₃, the two components are linked by an intermolecular hydrogen bond between the O—H and N—O groups [O?O 2.577 (3) Å]. The interplanar angle between the planes of the rings of the mol­ecules is 5.3 (2)°. The rings are stacked in the crystal with a mean interplanar distance of 3.279 (3) Å.     

2‐[(4‐Hydroxyphenyl)iminomethyl]­thiophene

The molecular structure of the title compound, C₁₁H₉NOS, has three planar moieties, two of which are rings, namely the hydroxy­phenyl and the thio­phene, with an angle of 20.76 (10)° between them. The crystal structure is stabilized by an O—H?N hydrogen bond and by C—H?O intermolecular interactions. The C?O intermolecular contact distance is 3.443 (2) Å.     

3‐[(2‐Oxo‐1‐naphthylidene)methyl­amino]­benzoic acid

The title compound, C₁₈H₁₃NO₃, exists as a keto­amino tautomer implying a fairly short N—H?O intramolecular hydrogen bond between the 2‐naphthalenone and amino moieties [N?O 2.531 (3) Å] which is enhanced by the π‐electron delocalization effect. The naphthald­imine and 3‐carboxy­phenyl fragments are inclined at an angle of 4.41 (7)°, so the mol­ecule is almost planar. The mol­ecules are connected by intermolecular O—H?O hydrogen bonds between the carboxy and keto O atoms, forming infinite chains around the twofold screw axes parallel to b .     

2:1 Complexes of 2‐chloro‐4‐nitro­benzoic acid and 2‐chloro‐5‐nitro­benzoic acid with pyrazine

2‐Chloro‐4‐nitro­benzoic acid and 2‐chloro‐5‐nitro­benzoic acid form O—H?N hydrogen bonds with pyrazine to afford 2:1 complexes of 2C₇H₄ClNO₄·C₄H₄N₂, (I) and (II), respectively, that are located on inversion centers. The 2C₇H₄ClNO₄·­C₄H₄N₂ units in both complexes are connected by weak C—H?O hydrogen bonds; the units build a three‐dimensional hydrogen‐bond network in (I) and a ribbon structure in (II).     

2‐(4‐Acetyl‐3,5‐di­hydroxy‐2‐methyl­phenoxy)‐4,6‐di­methoxy‐3‐methyl­benzoic acid

In the title compound, C₁₉H₂₀O₈, the benzene rings are nearly perpendicular to each other [dihedral angle 80.2 (2)°]. The carboxy group is twisted out while both the methoxy and acetyl groups are almost coplanar with their attached benzene rings. The hydroxy group is involved in an intramolecular O—H?O hydrogen bond with the acetyl O atom and the compound is connected through an intermolecular O—H?O contact to form a dimer. The crystal structure is stabilized by intermolecular O—H?O hydrogen bonds.     

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°].     

(E)‐N′‐(4‐Chlorobenzylidene)‐, (E)‐N′‐(4‐bromobenzylidene)‐ and (E)‐N′‐[4‐(diethylamino)benzylidene]‐ derivatives of 4‐hydroxybenzohydrazide

The 4‐chloro‐ [C₁₄H₁₁ClN₂O₂, (I)], 4‐bromo‐ [C₁₄H₁₀BrN₂O₂, (II)] and 4‐diethylamino‐ [C₁₈H₂₁N₃O₂, (III)] derivatives of benzylidene‐4‐hydroxybenzohydrazide, all crystallize in the same space group (P2₁/c), (I) and (II) also being isomorphous. In all three compounds, the conformation about the C=N bond is E. The molecules of (I) and (II) are relatively planar, with dihedral angles between the two benzene rings of 5.75 (12) and 9.81 (17)°, respectively. In (III), however, the same angle is 77.27 (9)°. In the crystal structures of (I) and (II), two‐dimensional slab‐like networks extending in the a and c directions are formed via N—H...O and O—H...O hydrogen bonds. The molecules stack head‐to‐tail viaπ–π interactions involving the aromatic rings [centroid–centroid distance = 3.7622 (14) Å in (I) and 3.8021 (19) Å in (II)]. In (III), undulating two‐dimensional networks extending in the b and c directions are formed via N—H...O and O—H...O hydrogen bonds. The molecules stack head‐to‐head viaπ–π interactions involving inversion‐related benzene rings [centroid–centroid distances = 3.6977 (12) and 3.8368 (11) Å].     

Hydrogen bonding in 2‐amino‐4,6‐dimethoxypyrimidine, 2‐benzylamino‐4,6‐bis(benzyloxy)pyrimidine and 2‐amino‐4,6‐bis(N‐pyrrolidino)pyrimidine: chains of fused rings and a centrosymmetric dimer

Molecules of 2‐amino‐4,6‐di­methoxy­pyrimidine, C₆H₉N₃O₂, (I), are linked by two N—H?N hydrogen bonds [H?N 2.23 and 2.50 Å, N?N 3.106 (2) and 3.261 (2) Å, and N—H?N 171 and 145°] into a chain of fused rings, where alternate rings are generated by centres of inversion and twofold rotation axes. Adjacent chains are linked by aromatic π–π‐stacking interactions to form a three‐dimensional framework. In 2‐­benzylamino‐4,6‐bis(benzyloxy)pyrimidine, C₂₅H₂₃N₃O₂, (II), the mol­ecules are linked into centrosymmetric R(8) dimers by paired N—H?N hydrogen bonds [H?N 2.13 Å, N?N 2.997 (2) Å and N—H?N 170°]. Molecules of 2‐amino‐4,6‐bis(N‐pyrrolidino)­pyrimidine, C₁₂H₁₉N₅, (III), are linked by two N—H?N hydrogen bonds [H?N 2.34 and 2.38 Å, N?N 3.186 (2) and 3.254 (2) Å, and N—H?N 163 and 170°] into a chain of fused rings similar to that in (I).     

2‐Amino‐4‐(4‐pyridyl)­pyrimidine and the 1:1 adduct with 4‐amino­benzoic acid

The structure of the title compound, C₉H₈N₄, comprises non‐planar mol­ecules that associate via pyrimidine N—H?N dimer R(8) hydrogen‐bonding associations [N?N 3.1870 (17) Å] and form linear hydrogen‐bonded chains via a pyrimidine N—H?N(pyridyl) interaction [N?N 3.0295 (19) Å]. The dihedral angle between the two rings is 24.57 (5)°. The structure of the 1:1 adduct with 4‐amino­benzoic acid, C₉H₈N₄·C₇H₇NO₂, exhibits a hydrogen‐bond­ing network involving COOH?N(pyridyl) [O?N 2.6406 (17) Å], pyrimidine N—H?N [N?N 3.0737 (19) and 3.1755 (18) Å] and acid N—H?O interactions [N?O 3.0609 (17) and 2.981 (2) Å]. The dihedral angle between the two linked rings of the base is 38.49 (6)° and the carboxyl­ic acid group binds to the stronger base group in contrast to the (less basic) complementary hydrogen‐bonding site.     

3‐Acetyl‐4‐benzoyl‐2‐methyl‐5‐phenyl‐3,3a‐di­hydro­pyrazolo­[2,3‐c]pyrimidine‐7(6H)‐thione

The mol­ecule of the title compound, C₂₂H₁₉N₃O₂S, is not planar. The dihedral angle between the two phenyl rings is 27.46 (7)° and in the di­hydro­pyrazolo­pyrimidine ring the total puckering amplitude Q_T is 0.526 (3) Å. The structure is stabilized by both intra‐ and intermolecular C—H?O interaction, and by an intermolecular N—H?S hydrogen bond.     

(E)‐2‐Methyl‐5‐(1‐naphthyl­methyl)­cinnamic acid

The title compound, C₂₁H₁₈O₂, crystallized in the centrosymmetric space group P2₁/n with one mol­ecule in the asymmetric unit. There is a single hydrogen bond, with an O_donor?O_acceptor distance of 2.624 (2) Å, which forms a cyclic dimer about a center of symmetry. The carboxyl group O atoms are ordered, while the carboxyl‐H atom is disordered. A single leading intermolecular C—H?O interaction has an H?O distance of 2.68 Å and a C—H?O angle of 178°; this interaction forms chains. Taken together with the hydrogen bond, it generates chains and rings. Structural comparisons are made with trans‐cinnamic acid and with 4‐methyl‐trans‐cinnamic acid.     

Coordinative NB bond formation and hydrogen‐bonded molecular ladders in 2,5‐bis[(N→B)‐(2‐aminoethoxy)phenylboryl]thiophene

The molecular structure of the title compound, C₂₀H₂₄B₂­N₂O₂S, is characterized by a twofold rotation axis passing through the S atom and the midpoint of the C—C single bond in the thio­phene ring. A coordinative NB bond is present in the boroxazolidine ring and a single N—H?O hydrogen bond [H?O 1.93 (3) Å, N?O 2.829 (3) Å and N—H?O 172 (2)°] links the mol­ecules into a molecular ladder.     

Intermolecular O—H⃛O hydrogen bonding in the three independent molecules of (2S)‐3‐(4‐hydroxyphenyl)‐2‐(1‐oxoisoindolin‐2‐yl)­propanoic acid

The title compound, C₁₇H₁₅NO₄, derived from l ‐tyrosine, crystallizes with three independent mol­ecules which differ in the conformation of the asymmetric unit: the N—C—C—C_ipso torsion angles are ?71.7 (5), ?63.6 (6) and ?52.5 (5)°, respectively. Deformations in the phenol ring hydroxy O—C—C angles of 116.5 (4)/123.9 (4), 121.7 (5)/118.1 (4) and 122.4 (5)/118.6 (5)°, respectively, result from their respective intermolecular hydrogen‐bonding environments. Intermolecular O_acid—H?O=C_indole, O_phenol—H?O—H_phenol and O_phenol—H?O=C_indole hydrogen bonds, with O?O distances in the range 2.607 (4)–2.809 (4) Å, are present in combination with C—H?O and C—H?π_arene interactions. The primary hydrogen‐bonding systems assemble with graph sets R₃³(8) and R₃²(22).     

catena‐Poly­[[di­aqua­lithium(I)]‐μ‐[9H‐purine‐2,6(1H,3H)‐dionato‐O2:N7]]

In the title compound, [Li(C₅H₃N₄O₂)(H₂O)₂]_n, the coordinate geometry about the Li⁺ ion is distorted tetrahedral and the Li⁺ ion is bonded to N and O atoms of adjacent ligand mol­ecules forming an infinite polymeric chain with Li—O and Li—N bond lengths of 1.901 (5) and 2.043 (6) Å, respectively. Tetrahedral coordination at the Li⁺ ion is completed by two cis water mol­ecules [Li—O 1.985 (6) and 1.946 (6) Å]. The crystal structure is stabilized both by the polymeric structure and by a hydrogen‐bond network involving N—H?O, O—H?O and O—H?N hydrogen bonds.     

The dinuclear copper(II) complexes di‐μ‐chlorido‐bis{[N,N′‐bis(4‐chlorobenzyl)propane‐1,2‐diamine]chloridocopper(II)} and di‐μ‐chlorido‐bis{[N,N′‐bis(3,4‐methylenedioxybenzyl)propane‐1,2‐diamine]chloridocopper(II)}

The two title dinuclear copper(II) complexes, [Cu₂Cl₄(C₁₇H₂₀Cl₂N₂)₂], (I), and [Cu₂Cl₄(C₁₉H₂₂N₂O₄)₂], (II), have similar coordination environments. In each complex, the asymmetric unit consists of one half‐molecule and the two copper centres are bridged by a pair of Cl atoms, resulting in complexes with centrosymmetric structures containing Cu(μ‐Cl)₂Cu parallelogram cores; the Cu...Cu separations and Cu—Cl—Cu angles are 3.4285 (8) Å and 83.36 (3)°, respectively, for (I), and 3.565 (2) Å and 84.39 (7)° for (II). Each Cu atom is five‐coordinated and the coordination geometry around the Cu atom is best described as a distorted square‐pyramid with a τ value of 0.155 (3) for (I) and 0.092 (7) for (II). The apical Cu—Cl bond length is 2.852 (1) Å for (I) and 2.971 (2) Å for (II). The basal Cu—Cl and Cu—N average bonds lengths are 2.2673 (9) and 2.030 (2) Å, respectively, for (I), and 2.280 (2) and 2.038 (6) Å for (II). The molecules of (I) are linked by one C—H...Cl hydrogen bond into a complex [10] sheet. The molecules of (II) are linked by one C—H...Cl and one N—H...O hydrogen bond into a complex [100] sheet.     

Hydro­gen bonds and C—H⃛O interactions in N‐(2‐hydroxy‐1,1‐dimethyl­ethyl)benzamide at 150 K

The title compound, C₁₁H₁₅NO₂, crystallized in the centrosymmetric space group P2₁/n with one mol­ecule in the asymmetric unit. There is a single intermolecular hydrogen bond, in which the N_donor?O_acceptor distance is 3.0374 (11) Å and the N—H?O angle is 171.0 (12)°. The single intramol­ecular hydrogen bond has an O_donor?O_acceptor distance of 2.6279 (11) Å and an O—H?O angle of 161.8 (14)°. The four leading intermolecular C—H?O interactions have H?O distances ranging from 2.52 to 2.65 (2) Å and C—H?O angles ranging from 125.2 (9) to 143°. Chains of interactions form two‐dimensional networks.