A series of N-(2-phenylethyl)nitroaniline derivatives is presented, demonstrating that modest changes in the functional groups cause significant differences in molecular conformation, intermolecular interactions and packing.
2,4-Dinitro-N-(2-phenylethyl)aniline, C14H13N3O4, (I), crystallizes with one independent molecule in the asymmetric unit. The adjacent amine and nitro groups form an intramolecular N—H⋯O hydrogen bond. The anti conformation about the ethyl C—C bond leads to the phenyl and aniline rings being essentially parallel. Molecules are linked into dimers by intermolecular N—H⋯O hydrogen bonds, such that each amine H atom participates in a three-centre interaction with two nitro O atoms. Though the dimers pack so that the arene rings of adjacent molecules are parallel, the rings are staggered and π–π interactions do not appear to be favoured. 4,6-Dinitro-N,N′-bis(2-phenylethyl)benzene-1,3-diamine, C22H22N4O4, (II), differs from (I) in the presence of a second 2-phenylethylamine group on the substituted ring. Compound (II) also crystallizes with one unique molecule in the asymmetric unit. Both amine groups are involved in intramolecular N—H⋯O hydrogen bonds with adjacent nitro groups. Although one ethyl group adopts an anti conformation as in (I), the other is gauche, with the result that the pendant phenyl rings are not parallel. The amine group that is part of the gauche conformation participates in a three-centre N—H⋯O hydrogen bond with the nitro group of a neighbouring molecule, leading to dimers as in (I). The other amine H atom does not form any intermolecular hydrogen bonds. The packing leads to separations of ca 3.4 Å of the parallel anti phenyl and aminobenzene rings. 2-Cyano-4-nitro-N-(2-phenylethyl)aniline, C15H13N3O2, (III), differs from (I) only in having a cyano group in place of the 2-nitro group. The absence of the adjacent nitro group eliminates the intramolecular N—H⋯O hydrogen bond. Molecules of (III) adopt the same anti conformation about the ethyl group as in (I), but crystallize in the higher-symmetry monoclinic space group P21/n. The molecules are linked into dimers via N—H⋯N amine–cyano hydrogen bonds, while the nitro groups are not involved in any N—H⋯O interactions. Owing to the different symmetry, the molecules pack in a herringbone pattern with fewer face-to-face interactions between the rings. The closest such interactions are about 3.5 Å between rings that are largely slipped past one another. 4-Methylsulfonyl-2-nitro-N-(2-phenylethyl)aniline, C15H16N2O4S, (IV), differs from (I) in having a methylsulfonyl group in place of the 4-nitro group. The intramolecular N—H⋯O hydrogen bond is present as in (I). However, unlike (I), the conformation about the ethyl group is gauche, so the two arene rings are nearly perpendicular rather than parallel. The packing is significantly different from the other three structures in that there are no intermolecular hydrogen bonds involving the N—H groups. The molecules are arranged in tetragonal columns running along the c axis, with the aniline rings mostly parallel and separated by ca 3.7 Å. Taken together, these structures demonstrate that modest changes in functional groups cause significant differences in molecular conformation, intermolecular interactions and packing.
crystal structure; N-(2-phenylethyl)nitroaniline derivatives; secondary amines; nitric oxide release agents
The title compound, C27H18N4O·2CH4O, is a unsymmetrically substituted quinoxaline. An intramolecular O—H⋯N hydrogen bond involving the hydroxy and imino groups generates an S(6) ring motif. Intermolecular C—H⋯O and N—H⋯O hydrogen bonds form an R
1(7) ring motif involving a methanol O atom and two H atoms of the imidazole and benzene rings, respectively. The latter links neighbouring molecules into one-dimensional extended chains along the a axis. The two benzene rings are inclined towards each other, as indicated by the dihedral angle of 52.13 (10)°. The phenol ring is almost coplanar with the basic quinoxaline unit, making a dihedral angle of 2.43 (6)°. The short distances between the centroids of the five- and six-membered rings prove the existence of π–π interactions [centroid–centroid distances = 3.5234 (9)–3.7885 (10) Å]. The crystal structure is stabilized by intramolecular O—H⋯N, intermolecular O—H⋯O, N—H⋯O and C—H⋯O (× 2) hydrogen bonds and weak intermolecular C—H⋯π and π–π interactions.
The title compounds are iron(II) dihalide complexes of the bulky arylimidazole ligand 1-(2,6-diisopropylphenyl)-1H-imidazole. The FeCl2 and FeBr2 complexes are isotypic, while the third compound, also an FeBr2 complex, crystallizes as a diethyl ether disolvate.
The title compounds, [FeCl2(C15H20N2)4], (I), [FeBr2(C15H20N2)4], (II), and [FeBr2(C15H20N2)4]·2C4H10O, (IIb), respectively, all have triclinic symmetry, with (I) and (II) being isotypic. The FeII atoms in each of the structures are located on an inversion center. They have octahedral FeX
2N4 (X = Cl and Br, respectively) coordination spheres with the FeII atom coordinated by two halide ions in a trans arrangement and by the tertiary N atom of four arylimidazole ligands [1-(2,6-diisopropylphenyl)-1H-imidazole] in the equatorial plane. In the two independent ligands, the benzene and imidazole rings are almost normal to one another, with dihedral angles of 88.19 (15) and 79.26 (14)° in (I), 87.0 (3) and 79.2 (3)° in (II), and 84.71 (11) and 80.58 (13)° in (IIb). The imidazole rings of the two independent ligand molecules are inclined to one another by 70.04 (15), 69.3 (3) and 61.55 (12)° in (I), (II) and (IIb), respectively, while the benzene rings are inclined to one another by 82.83 (13), 83.0 (2) and 88.16 (12)°, respectively. The various dihedral angles involving (IIb) differ slightly from those in (I) and (II), probably due to the close proximity of the diethyl ether solvent molecule. There are a number of C—H⋯halide hydrogen bonds in each molecule involving the CH groups of the imidazole units. In the structures of compounds (I) and (II), molecules are linked via pairs of C—H⋯halogen hydrogen bonds, forming chains along the a axis that enclose R
2(12) ring motifs. The chains are linked by C—H⋯π interactions, forming sheets parallel to (001). In the structure of compound (IIb), molecules are linked via pairs of C—H⋯halogen hydrogen bonds, forming chains along the b axis, and the diethyl ether solvent molecules are attached to the chains via C—H⋯O hydrogen bonds. The chains are linked by C—H⋯π interactions, forming sheets parallel to (001). In (I) and (II), the methyl groups of an isopropyl group are disordered over two positions [occupancy ratio = 0.727 (13):0.273 (13) and 0.5:0.5, respectively]. In (IIb), one of the ethyl groups of the diethyl ether solvent molecule is disordered over two positions (occupancy ratio = 0.5:0.5).
arylimidazole; iron(II); crystal structure
There is one cation–anion pair in the asymmetric unit of the title compound [systematic name: 4-(3-carboxy-6-fluoro-4-oxo-1,4-dihydroquinolin-7-yl)-1-ethylpiperazin-1-ium 2,4,6-trinitrophenolate], C19H23FN3O3
−. The six-membered piperazine group in the cation adopts a slightly distorted chair conformation and contains a protonated N atom. The dihedral angles between the mean planes of the cyclopropyl and piperazine rings in the cation with the 10-atom ring system of the quinolone group are 48.1 (1) and 69.9 (5)°, respectively. The picrate anion interacts with the protonated N atom of an adjacent cation through a bifurcated N—H⋯O three-center hydrogen bond, forming an R
2(6) ring motif. Furthermore, there is an intramolecular O—H⋯O hydrogen bond. The dihedral angle between the mean planes of the anion benzene and cation piperizine, quinoline and cyclopropyl rings are 61.3 (6), 31.1 (4) and 70.4 (9)°, respectively. The mean planes of the two o-NO2 and single p-NO2 groups in the picrate anion are twisted by 6.7 (6), 38.3 (9) and 12.8 (7)° with respect to the mean plane of the benzene ring. Strong N—H⋯O and weak intermolecular C—H⋯O hydrogen bonds in concert with weak π–π stacking interactions [centroid–centroid distances = 3.5785 (13), 3.7451 (12) and 3.6587 (13) Å] dominate the crystal packing.
There are two independent molecules (A and B) with similar conformations in the asymmetric unit of the title compound, C9H8ClN5S. The benzothiadiazole ring systems of both molecules are essentially planar [maximum deviation = 0.021 (2) Å in molecule A and 0.022 (1) Å in molecule B] and make dihedral angles of 68.78 (9) and 54.39 (8)°, respectively, with the mean planes of their 4,5-dihydro-1H-imidazole rings. An intramolecular N—H⋯Cl hydrogen bond occurs in molecule B. In the crystal, both molecules form centrosymmetric dimers through π-stacking of their benzothiadiazole rings, with interplanar distances of 3.3174 (7) and 3.2943 (6) Å. These dimers are further linked via pairs of N—H⋯N hydrogen bonds with the dihydroimidazole rings as the hydrogen-bonding donors and one of the benzothiadiazole N atoms as the acceptors, generating R
2(16) ring motifs. The A
2 and B
2 dimers in turn form additional N—H⋯N hydrogen bonds with the secondary amine as the H-atom donor and the dihydroimidazole N atom as the acceptor. These R
2(8)-type interactions connect the A
2 and B
2 dimers with each other, forming infinite chains along .
In the title compound, C17H19N5O5, obtained from the condensation reaction of 4-diethylamino-2-hydroxybenzaldehyde and 2,4-dinitrophenylhydrazine, the two benzene rings are twisted by a dihedral angle of 1.75 (12)°. The nitro groups are slightly twisted with the respect to the benzene ring to which they are attached, making dihedral angles of 8.20 (15) and 5.78 (15)°. An intramolecular O—H⋯N hydrogen bond occurs. In the crystal, molecules are linked by pairs of intermolecular N—H⋯O hydrogen bonds, forming dimers through R
2(12) rings. These dimers are further linked by C—H⋯O and C—H⋯π and weak slipped π–π interactions [centroid–centroid distance = 3.743 (2)Å]. One of the ethyl groups is disordered over two positions, with occupancy factors in the ratio 0.72:0.28.
In the title hydrated salt [systematic name: 1-(1,3-benzodioxol-5-ylmethyl)piperazin-1-ium 4-nitrobenzoate monohydrate], C12H17N2O2
−·H2O, the piperazinium ring of the cation adopts a slightly distorted chair conformation. The piperonyl and piperazine rings are rotated with respect to each other with an N—C—C—C torsion angle of 45.6 (2)°. In the anion, the nitro group is almost coplanar with the adjacent benzene ring, forming a dihedral angle of only 3.9 (4)°. In the crystal, the cations, anions and water molecules are linked through N—H⋯O and O—H⋯O hydrogen bonds into chains along the a axis. In addition, weaker intermolecular C—H⋯O interactions are also observed within the chains. The anions form centrosymmetric couples through π-stacking interactions, with an intercentroid distance of 3.681 (4) Å between the benzene rings.
The title compound, C13H16N4O4, is a new hydrazone. An intramolecular N—H⋯O hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The nitro groups in the ortho and para positions are almost coplanar with the benzene ring to which they are bound, making dihedral angles of 0.60 (11) and 3.18 (11)°, respectively. Pairs of intermolecular C—H⋯O hydrogen bonds link neighbouring molecules into inversion dimers with R
2(10) motifs. The crystal structure is further stabilized by intermolecular π–π interactions, with a benzene centroid-to-centroid distance of 3.6601 (4) Å.
The title compound, C18H21N3O3, is a potential bidentate Schiff base ligand. The whole molecule is disordered with a refined site-occupancy ratio of 0.567 (4):0.433 (4) and not just one ethyl group as reported previously [Sarojini et al. (2007 ▶). Acta Cryst. E63, o4782–o4782]. Using the whole molecule disorder, R values are much smaller than those published. An intramolecular O—H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The dihedral angle between the mean plane of the two benzene rings (major component) is 9.0 (5)°. The crystal structure shows short C⋯C [3.189 (15)–3.298 (12) Å] and C⋯O [2.983 (5)–3.149 (13) Å] contacts. Intermolecular C—H⋯O interactions link neighbouring molecules into dimers with R
2(18) motifs. In the crystal structure, these dimers are linked together by intermolecular C—H⋯O interactions into one-dimensional extended chains along the b axis. The crystal structure is further stabilized by intermolecular π–π stacking interactions [centroid–centroid distances = 3.458 (8)–3.691 (6) Å].
The asymmetric unit of the title compound, C5H7N2
−·C7H5NO4, consists of an aminopyridinium cation, a 4-nitrobenzoate anion and a neutral 4-nitrobenzoic acid molecule. The pyridine ring forms dihedral angles of 64.70 (5)° and 70.37 (5)°, respectively, with the benzene rings of 4-nitrobenzoic acid and 4-nitrobenzoate. In the crystal structure, the cations, anions and the neutral 4-nitrobenzoic acid molecules are linked by O—H⋯O and N—H⋯O hydrogen bonds, forming a two-dimensional network parallel to (001). Adjacent networks are cross-linked via C—H⋯O hydrogen bonds and π–π stacking interactions [centroid–centroid distances 3.6339 (6) and 3.6566 (6) Å].
In the title compound, C24H18Cl4N4, the pyrimidine ring makes dihedral angles of 19.1 (2), 4.1 (2) and 67.5 (2)°, respectively, with phenyl and two benzene rings, and the molecular conformation is stabilized by an intramolecular N—H⋯N hydrogen bond closing a six-membered ring with an S(6) motif. In the crystal, a pair of intermolecular N—H⋯N hydrogen bonds connect two molecules, forming inversion dimers with R
2(12) motifs. C—H⋯π interactions links the dimers into a chain running along the a-axis direction. There are also π–π stacking interactions [centroid–centroid distance = 3.666 (4) Å] between the benzene rings of adjacent chains.
The title CoII complex, [Co(C9H9O2)2(C10H14N2O)2(H2O)2], contains two 4-ethylbenzoate (PEB), two monodentate diethylnicotinamide (DENA) ligands and two water molecules. The four O atoms in the equatorial plane around the CoII ion form a slightly distorted square-planar arrangement, while the slightly distorted octahedral coordination is completed by the two N atoms of the DENA ligands in the axial positions. Intramolecular O—H⋯O hydrogen bonds link the water molecules to the carboxylate groups. The dihedral angles between the carboxylate groups and the adjacent benzene rings are 4.52 (18) and 4.56 (18)°, while the pyridine rings and the benzene rings are oriented at dihedral angles of 7.76 (10) and 5.67 (13)°. In the crystal, intermolecular O—H⋯O hydrogen bonds link the molecules into chains propagating along . C—H⋯O interactions and a π–π contact between the pyridine rings [centroid–centroid distance = 3.476 (2) Å] are also observed.
The title CuII complex, [Cu(C9H9O2)2(C10H14N2O)2(H2O)2], contains two 4-ethylbenzoate (PEB) ligands, two monodentate diethylnicotinamide (DENA) ligands and two water molecules. The four O atoms in the equatorial plane around the CuII ion form a slightly distorted square-planar arrangement, while the distorted octahedral coordination is completed by the two N atoms of the DENA ligands in the axial positions. Intramolecular O—H⋯O hydrogen bonds link the water molecules to the carboxylate groups. The dihedral angles between the carboxylate groups and the adjacent benzene rings are 4.6 (3) and 3.7 (2)°, while the pyridine rings and the benzene rings are oriented at dihedral angles of 6.82 (11) and 3.63 (14)°. In the crystal, intermolecular O—H⋯O hydrogen bonds link the molecules into chains propagating along . C—H⋯O interactions and a π–π contact between the pyridine rings [centroid–centroid distance = 3.469 (2) Å] are also observed.
In the asymmetric unit of the title compound, C13H13N3O3, the 2-(2-methoxphenyl)ethenyl unit is connected to the methyl-nitroimidazole 1-methyl-4-nitro-1H-imidazole moiety. The molecule is quasi-planar and the planes of the two rings form a dihedral angle of 0.92 (11)°. The crystal packing can be described as layers parallel to the (011) plane, stabilized by intermolecular C—H⋯O hydrogen bonding, resulting in the formation of an infinite three-dimensional network linking these layers. Strong π–π stacking interactions are observed, viz. benzene–benzene, imidazole–imidazole and benzene–imidazole rings, with centroid–centroid distances of 3.528 (2), 3.457 (2) and 3.544 (2) Å, respectively. Intensity statistics indicated twinning by non-merohedry, with refined weighs of the twin components of 0.3687:0.6313.
crystal structure; hydrogen bonding; π–π stacking interactions; nitroimidazoles,
In the title molecule, C15H14N2O2, the substituted benzene ring forms a dihedral angle of 4.15 (1)° with the benzimidazole ring system. An intramolecular O—H⋯N hydrogen bond generates an S(6) ring motif. In the solid state, molecules are linked into chains along the  via intermolecular bifurcated N—H⋯(O,O) hydrogen bonds, which generate R
2(5) ring motifs. The crystal packing is also consolidated by C—H⋯π interactions, and π–π stacking interactions between the imidazole and substituted benzene rings [centroid–centroid distance = 3.5746 (13) Å]. The methyl group attached to the benzimidazole ring system is disordered over two positions with occupancies of 0.587 (6) and 0.413 (6), suggesting 180° rotational disorder for the benzimidazole group.
Solvent-dependent outcomes are noted in co-crystallization experiments between DABCO and 4-nitrobenzoic acid with mono- and diprotonated forms of DABCO are isolated.
The 1:1 co-crystallization of 1,4-diazabicyclo[2.2.2]octane (DABCO) with 4-nitrobenzoic acid in ethanol–water (3/1) gave the salt dihydrate C6H13N2
−·2H2O, (1), whereas from methanol, the salt C6H14N2
−, (2), was isolated. In (1), the cation and anion are linked by a strong N—H⋯O hydrogen bond, and the carboxylate anion is close to planar [dihedral angle between terminal residues = 6.83 (9)°]. In (2), a three-ion aggregate is assembled by two N—H⋯O hydrogen bonds, and the carboxylate anions are again close to planar [dihedral angles between terminal residues = 1.7 (3) and 5.9 (3)°]. Through the intervention of solvent water molecules, which self-assemble into helical supramolecular chains along the b axis, the three-dimensional architecture in (1) is stabilized by water–DABCO O—H⋯N and water–carboxylate O—H⋯O hydrogen bonds, with additional stability afforded by C—H⋯O interactions. The global crystal structure comprises alternating layers of water molecules and ion pairs stacked along the c axis. In the crystal of (2), the three-ion aggregates are assembled into a three-dimensional architecture by a large number of methylene–carboxylate/nitro C—H⋯O interactions as well as π–π contacts between inversion-related benzene rings [inter-centroid distances = 3.5644 (16) and 3.6527 (16) Å]. The cations and anions assemble into alternating layers along the c axis.
crystal structure; amine; carboxylic acid; co-crystallization; salt formation
The title Schiff base compound, C17H13N3O3, crystallizes in a zwitterionic form and exists in a trans configuration about the C=N bond. The molecule is slightly twisted, the dihedral angle between the benzene ring and naphthalene ring system being 10.80 (9)°. The nitro group is twisted relative to the plane of the benzene ring [dihedral angle = 8.88 (12)°]. Bifurcated intramolecular N—H⋯N and N—H⋯O hydrogen bonds formed between iminium groups and amine N atoms and naphthalen-2-olate O atoms generate S(5) and S(6) ring motifs, respectively. In the crystal, neighbouring zwitterions are linked through weak C—H⋯O interactions, giving rise to screw chains along . Molecules in these chains are linked to those of an adjacent chains through N—H⋯O hydrogen bonds and weak C—H⋯O interactions, forming sheets parallel to the ac plane. O⋯C [2.895 (3) Å] short contacts and π–π interactions [centroid–centroid distance = 3.8249 (19) Å] are also observed.
The title molecules, HL1 and HL2, differ in their conformation with the pyridine ring being inclined to the pyrazine ring by 61.34 (6) and 84.33 (12)°, respectively. The crystal packing is also slightly different, with molecules of HL1 linked by pairs of N—H⋯N hydrogen bonds, forming inversion dimers, while for HL2 molecules are linked by N—H⋯N and C—H⋯N hydrogen bonds, forming chains along .
The title compounds, C11H10N4O (HL1) and C11H10N4O (HL2), are pyridine 2-ylmethyl and 4-ylmethyl derivatives, respectively, of pyrazine-2-carboxamide. HL1 was measured at 153 K and crystallized in the monoclinic space group P21/c with Z = 4. There has been a report of the same structure measured at room temperature but assumed to crystallize in the triclinic space group P-1 with Z = 4 [Sasan et al. (2008 ▶). Monatsh. Chem.
139, 773–780]. In HL1, the pyridine ring is inclined to the pyrazine ring by 61.34 (6)°, while in HL2 this dihedral angle is 84.33 (12)°. In both molecules, there is a short N—H⋯N interaction involving the pyrazine carboxamide unit. In the crystal of HL1, molecules are linked by N—H⋯N hydrogen bonds, forming inversion dimers with an R
2(10) ring motif. The dimers are linked via bifurcated-acceptor C—H⋯O hydrogen bonds, forming sheets lying parallel to (102). The sheets are linked via C—H⋯N hydrogen bonds, forming a three-dimensional structure. In the crystal of HL2, molecules are linked by N—H⋯N and C—H⋯N hydrogen bonds to form chains propagating along . The chains are linked via C—H⋯O hydrogen bonds, forming sheets lying parallel to (100). Within the sheets there are π–π interactions involving neighbouring pyrazine rings [inter-centroid distance = 3.711 (15) Å]. Adjacent sheets are linked via parallel slipped π–π interactions involving inversion-related pyridine rings [inter-centroid distance = 3.6395 (17) Å], forming a three-dimensional structure.
crystal structure; pyrazine; pyridine; carboxamide
In the title compound, C25H26N2OS, the diethyl-substituted benzene ring forms dihedral angles of 67.38 (9) and 55.32 (9)° with the terminal benzene rings. The molecule adopts a trans–cis conformation with respect to the orientations of the diphenylmethane and 1,3-diethylbenzene groups with respect to the S atom across the C—N bonds. This conformation is stabilized by an intramolecular N—H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, pairs of N—H⋯S hydrogen bonds link the molecules into inversion dimers, forming R
2(6) loops. The dimer linkage is reinforced by a pair of C—H⋯S hydrogen bonds, which generate R
2(8) loops. Weak C—H⋯π and π–π [centroid–centroid seperation = 3.8821 (10) Å] interactions also occur in the crystal structure.
In the title compound, C11H12N2O5, the conformation of the N—H bond in the amide segment is syn to the ortho-nitro group in the benzene ring. The amide C=O and the carboxyl C=O of the acid segment are syn to each other and both are anti to the H atoms on the adjacent –CH2 groups. Furthermore, the C=O and O—H bonds of the acid group are in syn positions with respect to each other. The dihedral angle between the benzene ring and the amide group is 36.1 (1)°. The amide H atom shows bifurcated intramolecular hydrogen bonding with an O atom of the ortho-nitro group and an intermolecular hydrogen bond with the carbonyl O atom of another molecule. In the crystal, the N—H⋯O(C) hydrogen bonds generate a chain running along the  direction. Inversion dimers are formed via a pair of O—H⋯O(C) interactions, that form an eight-membered hydrogen-bonded ring involving the carboxyl group.
The title compound, C11H13N3S, exists in the 5-thioxo tautomeric form. The benzene ring exhibits disorder with a refined ratio of 0.77 (2):0.23 (2) for components A and B with a common bridgehead C atom. The 1,2,4-triazole ring is essentially planar, with a maximum deviation of 0.002 (3) Å for the benzyl-substituted C atom, and forms dihedral angles of 88.94 (18) and 86.56 (49)° with the benzene rings of components A and B, respectively. The angle between the plane of the ethyl chain and the mean plane of 1,2,4-triazole ring is 88.55 (15)° and this conformation is stabilized by an intramolecular C—H⋯S contact. In the crystal, pairs of N—H⋯S hydrogen bonds link molecules into inversion dimers. π–π interactions are observed between the triazole and benzene rings, with centroid–centroid separations of 3.547 (4) and 3.544 (12) Å for components A and B, and slippages of 0.49 (6) and 0.58 (15) Å, respectively.
In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming inversion dimers, which are linked by a further N—H⋯O hydrogen bond, forming chains along . There are intra- and intermolecular C—H⋯π interactions present, the latter linking the chains to form a three-dimensional supramolecular structure.
In the title compound, C27H21ClN2O4, the mean planes of the two indole ring systems (r.m.s. deviations = 0.021 and 0.024 Å) are approximately perpendicular to one another, with a dihedral angle of 79.54 (12)°. The benzene ring is twisted with respect to the mean planes of the two indole ring systems at angles of 80.14 (15) and 86.30 (15)°. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming inversion dimers with an R
2(18) ring motif. The dimers are linked by a further N—H⋯O hydrogen bond, forming chains along . There are intra- and intermolecular C—H⋯π interactions present, the latter linking the chains to form a three-dimensional supramolecular structure.
crystal structure; indole; bis-indolymethane; MRI contrast agent; N—H⋯O hydrogen bonds; C—H⋯π interactions
The title molecule, C13H10N2O, is essentially planar, the maximum deviation from the plane of the non-H atoms being 0.016 (2) Å. The imidazole ring makes a dihedral angle of 0.37 (13)° with the attached benzene ring. An intramolecular O—H⋯N hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked through N—H⋯O hydrogen bonds, forming chains propagating in . The crystal packing also features four π–π stacking interactions involving the imidazole ring, fused benzene ring and attached benzene ring system [centroid–centroid distances = 3.6106 (17), 3.6108 (17), 3.6666 (17) and 3.6668 (17) Å].
In the title compound, C14H15N5O4, the central –C=N—N—C(=O)—C– bridge is nearly planar [maximum deviation = 0.037 (1) Å] and forms dihedral angles of 7.37 (9) and 73.33 (5)°, respectively, with the benzene and imidazole rings. The dihedral angle between the benzene and imidazole rings is 66.08 (9)°. The methoxy and nitro groups are nearly coplanar with the benzene and imidazole rings, respectively, with a C—O—C—C torsion angle of 5.9 (2)° and an O—N—C—C angle of −0.2 (2)°. In the crystal, molecules are linked by a pair of N—H⋯O hydrogen bonds with an R
2(8) ring motif, forming an inversion dimer. The dimers are further interconnected by C—H⋯O hydrogen bonds into a sheet parallel to the (111) plane. A C—H⋯π interaction is also observed between the sheets.
The molecule of the title ZnII complex, [Zn(C9H10NO2)2(C6H6N2O)(H2O)2], contains two 4-(dimethylamino)benzoate (DMAB) ligands, one isonicotinamide (INA) ligand and two water molecules; one of the DMAB ions acts as a bidentate ligand while the other and INA are monodentate ligands. The four O atoms in the equatorial plane around the Zn atom form a distorted square-planar arrangement, while the distorted octahedral coordination is completed by the N atom of the INA ligand and the O atom of the water molecule in the axial positions. Intramolecular C—H⋯O hydrogen bonding results in the formation of a six-membered ring adopting an envelope conformation. The dihedral angle between the carboxyl groups and the adjacent benzene rings are 4.87 (16) and 2.2 (2)°, while the two benzene rings are oriented at a dihedral angle of 65.13 (8)°. The dihedral angle between the benzene and pyridine rings are 11.47 (7) and 74.83 (8)°, respectively. In the crystal structure, intermolecular O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds link the molecules into a supramolecular structure. π–π contacts between the pyridine and benzene rings and between the benzene rings [centroid–centroid distances = 3.695 (1) and 3.841 (1) Å, respectively] further stabilize the structure. Weak intermolecular C—H⋯π interactions are also present.