The structure of the title trifluoroacetic acid adduct, C17H12N2O3·C2HF3O2, contains a trifluoroacetic acid molecule hydrogen bonded to the imine N atom of the imidazole ring of a nearly planar four-fused-ring system (r.m.s. deviatiation = 0.013 Å). The carboxylic acid group of the triflouroacetic acid molecule is twisted with respect to the mean plane of the four-fused-ring sytem by 75.9 (2)°. A short intramolecular C—H⋯O hydrogen bond occurs. In the crystal, the adduct molecules are arranged into stacks along the b axis via π–π interactions between imidazole rings and between imidazole and one of the benzene rings [centroid–centroid distances 3.352 (2) and 3.485 (2) Å, respectively]. Molecules are linked via C—H⋯O hydrogen bonds, forming an alternating polymeric head-to-head/tail-to-tail stepped chain approximately along the a-axis direction and tilted on an axis bisecting the b and c axes.
The title molecule, C13H8N4, is is essentially planar [r.m.s. deviation for all non-H atoms = 0.025 (3) Å]. In the crystal, molecules are connected through one weak bifurcated N—H⋯(N,N) hydrogen bond and three π–π stacking interactions between pyridine and imidazole rings [centroid–centroid distance = 3.631 (8) Å] and between pyridine and benzene rings [centroid–centroid distances = 3.675 (5) and 3.666 (2) Å].
The asymmetric unit of the title compound, C21H15Cl2N5O4, contains two independent molecules (A and B) having similar conformations. The amine (NH2) group forms an intramolecular hydrogen bond with the benzoyl group, giving an S(6) ring motif in both molecules. The central six-membered rings adopt sofa conformations and the imidazole rings are planar (r.m.s deviations = 0.0150 and 0.0166 Å). The pyridine and imidazole rings are inclined to one another by 3.54 (1) and 3.03 (1)° in molecules A and B, respectively. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming chains along the a axis which enclose R
2(16) ring motifs. The rings are linked by weak N—H⋯O and C—H⋯O hydrogen bonds and C—H⋯π interactions forming sheets lying parallel to (001). A region of disordered electron density, most probably disordered solvent molecules, occupying voids of ca 753 Å3 for an electron count of 260, was treated using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155]. Their formula mass and unit-cell characteristics were not taken into account during refinement.
crystal structure; spiro; imidazole; pyridine-indoline C—H⋯π interactions; hydrogen bonding
In the title compound, C21H20N4O2, the statistically planar 1H-limidazole ring [maximum deviation = 0.003 (1) Å] makes dihedral angles of 1.33 (9) and 8.23 (7)°, respectively, with the essentially planar fused pyridine ring [maximum devation = 0.018 (1) Å] and the pendant benzene ring, which is attached to the pyridine ring by an —NH— group. An intramolecular C—H⋯N interaction, which generates an S(6) ring, helps to estalish the molecular conformation. In the crystal, the molecules are linked by N—H⋯O, C—H⋯O and O—H—N hydrogen bonds, which generate bifurcated R
2(6) and R
2(9) ring motifs, resulting in supramolecular  chains. The crystal structure also features weak π–π stacking [centroid–centroid distance = 3.5943 (9) Å] and C—H⋯π interactions.
In the title compound C21H17N5O4·C2H6OS, the central six-membered ring derived from 1,4-dihydropyridine adopts a distorted boat conformation with a small puckering amplitude of 0.127 (3) Å. The sums of bond angles around the pyridine N atom [358.7 (2)°] and the other imidazolidine N atom [60 (2)°] indicate that these atoms are in sp2 hybridization, leading to an essentially planar imidazolidine ring. The last heterocycle, an oxindole moiety, is also nearly planar with an r.m.s. deviation of 0.0185 (1) Å. The amine NH2 group forms an intramolecular hydrogen bond with the benzoyl group, giving a S(6) motif. In the crystal, N—H⋯O hydrogen bonds lead to the formation of chains along the c-axis direction. Within the chains there are further N—H⋯O and C—H⋯O hydrogen bonds enclosing R
2(14) ring motifs. The chains are linked via N—H⋯O and C—H⋯O hydrogen bonds involving the dimethyl sulfoxide solvent molecule which acts as both an acceptor and a donor..
The organic cation of the title salt, C17H12N4O2+·2Cl−·H2O, is nearly planar, the dihedral angle between two pyridine rings being 2.53 (16)° and that between the pyridinum and furan rings being 4.17 (19)°. Molecules are linked via N—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds, forming a three-dimensional framework and π–π stacking interactions help to stabilize the crystal structure [the imidazole–pyridine and imidazole–benzene centroid–centroid distances are 3.501 (3) and 3.674 (3) Å; respectively].
In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5)°]. The pyridine ring makes a dihedral angle of 35.5 (5)° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking interaction between the phenyl rings of neighbouring molecules [centroid–centroid distance = 3.772 (2) Å, interplanar distance = 3.546 (2) Å and slippage = 1.286 (2) Å].
The title compound, C19H15Cl2N3O2, was obtained by a one-step cyclocondensation of 2-amino-1-(4-chlorophenyl)imidazoline with diethyl (2-chlorobenzyl)malonate under basic conditions. In the crystalline state, the molecule exists as the 7-hydroxy-5-oxo tautomer. The dihedral angles between the fused imidazopyrimidine and aromatic chlorophenyl and chlorobenzyl rings are 14.2 (1) and 70.7 (1)°, respectively. The conformation of the molecule is influenced by the intramolecular C—H⋯O and C—H⋯N hydrogen bonds, giving a nearly planar five-ring fused system [maximum deviation from the mean plane = 0.296 (2) Å]. In the crystal structure, strong intermolecular O—H⋯O hydrogen bonds link the molecules into chains along the c axis. These chains are further stabilized by weak C—H⋯Cl and π–π interactions [centroid–centroid distance = 3.6707 (12) Å].
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.
In the title compound, C22H18BrN5O4, the central six-membered ring, derived from 1,4-dihydropyridine, adopts a distorted boat conformation with a puckering amplitude of 0.197 (3) Å, the imidazole ring adopts a twisted conformation with a puckering amplitude of 0.113 (3) Å, and the oxindole moiety is planar with an r.m.s. deviation of 0.0125 Å. Two intramolecular N—H⋯O hydrogen bonds are formed, each closing an S(6) loop. In the crystal, strong N—H⋯O hydrogen bonds lead to the formation of zigzag chains along the c axis. These are consolidated in the three-dimensional crystal packing by weak N—H⋯O hydrogen bonding, as well as by C—H⋯O, C—H⋯Br and C—H⋯π interactions. A small region of electron density well removed from the main molecule was removed with the SQUEEZE procedure in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155] following unsuccessful attempts to model it as a plausible solvent molecule. The unit-cell characteristics do not take into account this feature of the structure.
In the title compound, C15H17N3O, the 1H-imidazo[4,5-c]quinoline ring system is approximately planar, with a maximum deviation of 0.036 (1) Å. The C—N—C—C torsion angles formed between this ring system and the isobutyl unit are −99.77 (16) and 79.71 (17)°. In the crystal, intermolecular C—H⋯O hydrogen bonds link the molecules into chains along the c axis.
In the title compound, C14H11Cl2N5O, the plane of the 1H-imidazo[4,5-c]pyridine ring system [r.m.s. deviation = 0.087 (19) Å] makes a dihedral angle of 4.87 (10)° with the terminal phenyl ring. An intramolecular N—H⋯N hydrogen bond stabilizes the molecular conformation. In the crystal, N—H⋯O hydrogen bonds link the molecules into inversion dimers. These dimers are connected by π–π interactions between imidazole rings [shortest centroid–centroid distance = 3.4443 (14) Å].
The two fused five- and six-membered rings building the molecule of the title compound, C13H10BrN3, are approximately planar, the largest deviation from the mean plane being 0.004 (2) Å. The dihedral angle between the imidazo[4,5-b]pyridine mean plane and that of the phenyl ring is 41.84 (11)°. The structure is held together by slipped π–π stacking between symmetry-related molecules, with an interplanar distance of 3.583 (1) Å and a centroid–centroid vector of 3.670 (2) Å.
In the title compound, C18H11BrN4OS, the imidazothiadiazole and benzisoxazole rings are individually planar with maximum deviations of 0.025 (3) 0.015 (4) Å, respectively, and are inclined at an angle of 23.51 (7)° with respect to each other. The planes of the imidazothiadiazole and bromophenyl rings are inclined at an angle of 27.34 (3)°. In the crystal, intermolecular C—H⋯N interactions result in chains of molecules along the b and c axes. Moreover, C—H⋯O interactions result in centrosymmetric head-to-head dimers with R
2(24) graph-set motifs. The molecular packing is further stabilized by π–π stacking interactions between the imidazole rings with a shortest centroid–centroid distance of 3.492 (3) Å. In addition, C—H⋯π interactions are observed in the crystal structure.
The title compound, C18H12N2O, comprises two aromatic fragments, viz., imidazo[2,1-a]isoquinoline and benzene, linked by oxygen and methylene bridges. Despite the absence of a common conjugative system within the molecule, it adopts an essentially planar conformation with an r.m.s. deviation of 0. 036 Å. In the crystal, due to this structure, molecules form stacks along the b axis by π⋯π stacking interactions, with shortest C⋯C distances in the range 3.340 (4)–3.510 (4) Å. The molecules are bound by intermolecular C—H⋯O interactions within the stacks and C—H⋯π interactions between the stacks.
Crystal structures of methyl 3-phenyl-4,5-dihydro-1H,3H-benzo[4,5]imidazo[2,1-c][1,4]oxazepine-4-carboxylate and methyl 1-methyl-3-phenyl-4,5-dihydro-1H,3H-benzo[4,5]imidazo[2,1-c][1,4]oxazepine-4-carboxylate
In two benzo[4,5]imidazo[2,1-c][1,4]oxazepine-4-carboxylates, the seven-membered oxazepane rings both have a twist-chair conformation. The dihedral angle between the phenyl ring and the benzimidazole ring system is significantly smaller in one of the compounds, viz. 73.42 (10) compared to 83.07 (17)°.
The title compounds, C19H18N2O3, (I), and C20H20N2O3, (II), differ only by a methyl substituent on the seven-membered oxazepine ring in (II). In both compounds, these rings have a twist-chair conformation. The phenyl ring makes a dihedral angle of 73.42 (10)° with the benzimidazole ring system mean plane (r.m.s. deviation = 0.015 Å) in (I) and 83.07 (7)° in (II) (r.m.s. deviation = 0.026 Å). The methyl carboxylate groups are planar to within 0.031 (2) in (I) and 0.003 (2) Å in (II). They are inclined to the phenyl and benzimidazole ring system by 33.78 (16) and 87.56 (14)°, respectively, in (I) and by 53.04 (12) and 60.22 (11)°, respectively, in (II). In the crystal of (I), molecules stack in a herringbone fashion and are linked by C—H⋯O hydrogen bonds, forming chains along . In the crystal of (II), there are no significant intermolecular interactions present.
crystal structure; oxazepine; benzimidazole; angiogenesis; natural products.
In the title compound, C15H17N3OS, the dihedral angle between the statistically planar imidazo[2,1-b][1,3,4]thiadiazole fused-ring system (r.m.s. deviation = 0.002 Å) and the methyoxbenzene ring is 4.52 (6)°. In the crystal, molecules are arranged into columns and stacked down the a axis. The crystal structure is stabilized by weak C—H⋯π and π–π interactions [centroid–centroid separations = 3.6053 (8) and 3.7088 (7) Å].
In the title compound, C14H15N3S, the imidazo[2,1-b][1,3,4]thiadiazole fused-ring system is close to planar, with a maximum deviation of 0.042 (1) Å, and the dihedral angle between it and the phenyl ring is 24.21 (6)°. The isobutyl group is disordered over two sets of sites in a 0.899 (9):0.101 (9) ratio. In the crystal, weak aromatic π–π stacking interactions involving the imidazole and thiadiazole rings with a centroid–centroid distance of 3.8067 (7) Å occur.
The reaction of propargyl bromide and 6-bromo-1,3-dihydroimidazo[4,5-b]pyridin-2-one in refluxing dimethylformamide yields the title compound, C12H8BrN3O, which features nitrogen-bound propadienyl and propynyl substituents. The imidazolopyridine fused ring is planar (r.m.s. deviation = 0.012 Å); the propadienyl chain is coplanar with the fused ring as it is conjugated with it, whereas the propynyl chain is not as the nitrogen-bound C atom is a methylene linkage. The acetylenic H atom is hydrogen bonded to the carbonyl O atom of an adjacent molecule, forming a helical chain runnning along the b axis.
Theasymmetric unit of the title salt, C19H17N2S+·Cl−·0.75H2O, contains two symmetrically independent formula units of the carbenium salt along with three water molecules. The water molecules are only 50% occupated, and one of them is positioned in a hydrophobic pocket not forming any hydrogen bonds. The conformation of the independent cations is very similar, with dihedral angles of 61.0 (2) and 61.5 (3)° between the benzene rings. They form quasi-centrosymmetric couples via π–π stacking interactions between the benzene and imidazo[2,1-b]thiazole rings [centroid–centroid distances = 3.718 (3) and 3.663 (3) Å]. In the crystal, O—H⋯Cl hydrogen bonds lead to the formation of a helical anion–water chain along the c-axis direction. The cations connect to the anion–water chain through C—H⋯Cl interactions, generating a three-dimensional supramolecular network. O—H⋯S hydrogen bonds and C—H⋯O interactions also occur.
In the title compound, C20H22BrN5O2·2H2O, the Schiff base molecule exists in an E conformation with respect to the acyclic C=N bond. An S(6) ring motif is formed via an intramolecular O—H⋯N hydrogen bond. The dihedral angle between the imidazo[1,2-a]pyridine system and the benzene ring is 84.62 (5)°. In the crystal, N—H⋯O, O—H⋯O, O—H⋯N, C—H⋯O and C—H⋯Br hydrogen bonds link the molecules into a three-dimensional network. The crystal packing is further stabilized by C—H⋯π and π–π interactions [centroid–centroid distance = 3.5365 (7) Å].
A redetermination of the crystal structure of minodronic acid monohydrate was carried out in order to provide accurate atomic coordinates and geometry information, whose knowledge is fundamental to elucidate the presumed polymorphism of the compound at room temperature.
In a previous study, the X-ray structure of the title compound, C9H12N2O7P2·H2O, was reported [Takeuchi et al., (1998 ▶). Chem. Pharm. Bull.
46, 1703–1709], but neither atomic coordinates nor details of the geometry were published. The structure has been redetermined with high precision as its detailed knowledge is essential to elucidate the presumed polymorphism of minodronic acid monohydrate at room temperature. The molecule crystallizes in a zwitterionic form with cationic imidazolium[1,2a]pyridine and anionic phosphonate groups. The dihedral angle formed by the planes of the pyridine and imidazole rings is 3.55 (9)°. A short intramolecular C—H⋯O contact is present. In the crystal, molecules are linked by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds and π–π interactions [centroid-to-centroid distance = 3.5822 (11) Å], forming a three-dimensional structure.
crystal structure; bisphosphonate; polymorphism; minodronic acid; hydrogen bonds; redetermination
In the title compound, C10H6F3N3, the imidazo[1,2-a]pyridine group is essentially planar with a maximum deviation of 0.021 (1) Å. The F atoms in the trifluoromethyl group and the methyl H atoms are each disordered over two sets of sites with refined site occupancies of 0.68 (1):0.32 (1). In the crystal, molecules are linked into infinite chains through two C—H⋯N interactions forming R
2(12) and R
2(8) hydrogen-bond ring motifs. These chains are stacked along the a axis.
In the title molecule, C17H15BrN4O2, the fused-ring system is essentially planar, the largest deviation from the mean plane being 0.015 (2) Å, and forms dihedral angles of 37.8 (2) and 35.5 (2)° with the phenyl and oxazolidine rings, respectively. The conformation adopted by the molecule is stabilized by an intramolecular π⋯π interaction [centroid–centroid distance = 3.855(2) Å] between oxazolidine and phenyl rings. The crystal packing features intermolecular C—H⋯N and C—H⋯O interactions.
In the title compound, C12H9ClN2S, the imidazo[2,1-b]thiazole fragment is planar (r.m.s. deviation = 0.003 Å), and the benzene ring is twisted slightly [by 5.65 (6)°] relative to this moiety. In the crystal, molecules are linked by π–π stacking interactions into columns along . The molecules within the columns are arranged alternatively by their planar rotation of 180°. Thus, in the columns, there are the two types of π–π stacking interactions, namely, (i) between two imidazo[2,1-b]thiazole fragments [interplanar distance = 3.351 (2) Å] and (ii) between an imidazo[2,1-b]thiazole fragment and the phenyl ring [interplanar distance = 3.410 (5) Å]. There are no short contacts between the columns.