scholarly journals Crystal structures ofN2,N3,N5,N6-tetrakis(pyridin-2-ylmethyl)pyrazine-2,3,5,6-tetracarboxamide andN2,N3,N5,N6-tetrakis(pyridin-4-ylmethyl)pyrazine-2,3,5,6-tetracarboxamide

Author(s):  
Dilovan S. Cati ◽  
Helen Stoeckli-Evans

The title compounds, C32H28N10O4· unknown solvent, (I), and C32H28N10O4, (II), are pyrazine-2,3,5,6-tetracarboxamide derivatives. In (I), the substituents are (pyridin-2-ylmethyl)carboxamide, while in (II), the substituents are (pyridin-4-ylmethyl)carboxamide. Both compounds crystallize in the monoclinic space groupP21/n, withZ′ = 1 for (I), andZ′ = 0.5 for (II). The whole molecule of (II) is generated by inversion symmetry, the pyrazine ring being situated about a center of inversion. In (I), the four pyridine rings are inclined to the pyrazine ring by 83.9 (2), 82.16 (18), 82.73 (19) and 17.65 (19)°. This last dihedral angle involves a pyridine ring that is linked to the adjacent carboxamide O atom by an intramolecular C—H...O hydrogen bond. In compound (II), the unique pyridine rings are inclined to the pyrazine ring by 33.3 (3) and 81.71 (10)°. There are two symmetrical intramolecular C—H...O hydrogen bonds present in (II). In the crystal of (I), molecules are linked by N—H...O and N—H...N hydrogen bonds, forming layers parallel to (10-1). The layers are linked by C—H...O and C—H...N hydrogen bonds, forming a three-dimensional framework. In the crystal of (II), molecules are linked by N—H...N hydrogen bonds, forming chains propagating along the [010] direction. The chains are linked by a weaker N—H...N hydrogen bond, forming layers parallel to the (101) plane, which are in turn linked by C—H...O hydrogen bonds, forming a three-dimensional structure. In the crystal of compound (I), a region of disordered electron density was treated with the SQUEEZE routine inPLATON[Spek (2015).Acta Cryst. C71, 9–18]. Their contribution was not taken into account during refinement. In compound (II), one of the pyridine rings is positionally disordered, and the refined occupancy ratio for the disordered Car—Car—Npyatoms is 0.58 (3):0.42 (3).

2015 ◽  
Vol 71 (12) ◽  
pp. o991-o992
Author(s):  
Kamel Ouari

In the title compound, C12H8BrN3O, the 4-bromophenol ring is coplanar with the planar imidazo[4,5-b]pyridine moiety (r.m.s deviation = 0.015 Å), making a dihedral angle of 1.8 (2)°. There is an intramolecular O—H...N hydrogen bond forming anS(6) ring motif. In the crystal, molecules are linkedviaN—H...N and O—H...Br hydrogen bonds, forming undulating sheets parallel to (10-2). The sheets are linked by π–π interactions [inter-centroid distance = 3.7680 (17) Å], involving inversion-related molecules, forming a three-dimensional structure.


Author(s):  
Montserrat Alfonso ◽  
Helen Stoeckli-Evans

In dimethyl 5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylate, C18H14N4O4, (I), and diethyl 5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylate, C20H18N4O4, (II), the dimethyl and diethyl esters of 5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylic acid, the orientation of the two pyridine rings differ. In (I), pyridine ringBis inclined to pyrazine ringAby 44.8 (2)° and the pyridine and pyrazine N atoms aretransto one another, while pyridine ringCis inclined to the pyrazine ring by 50.3 (2)°, with the pyridine and pyrazine N atomscisto one another. In compound (II), the diethyl ester, which possesses twofold rotation symmetry, the pyridine ring is inclined to the pyrazine ring by 40.7 (1)°, with the pyridine and pyrazine N atomstransto one another. In the crystal of (I), molecules are linked by C—H...N hydrogen bonds, forming chains along [001]. The chains are linked by C—H...π interactions, forming a three-dimensional structure. In the crystal of (II), molecules are linkedviaC—H...O hydrogen bonds, forming a three-dimensional framework. There are C—H...π interactions present within the framework.


Author(s):  
Sadashivamurthy Shamanth ◽  
Kempegowda Mantelingu ◽  
Haruvegowda Kiran Kumar ◽  
Hemmige S. Yathirajan ◽  
Sabine Foro ◽  
...  

Three title compounds, namely, 2-(4-chlorobenzyl)-5-[(1H-indol-3-yl)methyl]-6-phenylimidazo[2,1-b][1,3,4]thiadiazole, C26H19ClN4S, (I), 2-(4-chlorobenzyl)-6-(4-fluorophenyl)-5-[(1H-indol-3-yl)methyl]imidazo[2,1-b][1,3,4]thiadiazole, C26H18ClFN4S, (II), and 6-(4-bromophenyl)-2-(4-chlorobenzyl)-5-[(1H-indol-3-yl)methyl]imidazo[2,1-b][1,3,4]thiadiazole, C26H18BrClN4S, (III), have been prepared using a reductive condensation of indole with the corresponding 6-aryl-2-(4-chlorobenzyl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehydes (aryl = phenyl, 4-fluorophenyl or 4-bromophenyl), and their crystal structures have been determined. The asymmetric unit of compound (I) consists of two independent molecules and one of the molecules exhibits disorder of the 4-chlorobenzyl substituent with occupancies 0.6289 (17) and 0.3711 (17). Each type of molecule forms a C(8) chain motif built from N—H...N hydrogen bonds, which for the fully ordered molecule is reinforced by C—H...π interactions. In compound (II), the chlorobenzyl unit is again disordered, with occupancies 0.822 (6) and 0.178 (6), and the molecules form C(8) chains similar to those in (I), reinforced by C—H...π interactions involving only the major disorder component. The chlorobenzyl unit in compound (III) is also disordered with occupancies of 0.839 (5) and 0.161 (5). The molecules are linked by a combination of one N—H...N hydrogen bond and four C—H...π interactions, forming a three-dimensional framework.


2006 ◽  
Vol 62 (4) ◽  
pp. 651-665 ◽  
Author(s):  
Silvia Cuffini ◽  
Christopher Glidewell ◽  
John N. Low ◽  
Aline G. de Oliveira ◽  
Marcus V. N. de Souza ◽  
...  

Structures are reported here for eight further substituted N-aryl-2-chloronicotinamides, 2-ClC5H3NCONHC6H4 X-4′. When X = H, compound (I) (C12H9ClN2O), the molecules are linked into sheets by N—H...N, C—H...π(pyridyl) and C—H...π(arene) hydrogen bonds. For X = CH3, compound (II) (C13H11ClN2O, triclinic P\bar 1 with Z′ = 2), the molecules are linked into sheets by N—H...O, C—H...O and C—H...π(arene) hydrogen bonds. Compound (III), where X = F, crystallizes as a monohydrate (C12H8ClFN2O·H2O) and sheets are formed by N—H...O, O—H...O and O—H...N hydrogen bonds and aromatic π...π stacking interactions. Crystals of compound (IV), where X = Cl (C12H8Cl2N2O, monoclinic P21 with Z′ = 4) exhibit inversion twinning: the molecules are linked by N—H...O hydrogen bonds into four independent chains, linked in pairs by C—H...π(arene) hydrogen bonds. When X = Br, compound (V) (C12H8BrClN2O), the molecules are linked into sheets by N—H...O and C—H...N hydrogen bonds, while in compound (VI), where X = I (C12H8ClIN2O), the molecules are linked into a three-dimensional framework by N—H...O and C—H...π(arene) hydrogen bonds and an iodo...N(pyridyl) interaction. For X = CH3O, compound (VII) (C13H11ClN2O2), the molecules are linked into chains by a single N—H...O hydrogen bond. Compound (VIII) (C13H8ClN3O, triclinic P\bar 1 with Z′ = 2), where X = CN, forms a complex three-dimensional framework by N—H...N, C—H...N and C—H...O hydrogen bonds and two independent aromatic π...π stacking interactions.


Author(s):  
S. Subasri ◽  
Timiri Ajay Kumar ◽  
Barij Nayan Sinha ◽  
Venkatesan Jayaprakash ◽  
Vijayan Viswanathan ◽  
...  

The title compounds, C12H12ClN5OS, (I), and C12H12ClN5OS, (II), are 2-[(diaminopyrimidin-2-yl)sulfanyl]acetamides. Compound (II), crystallizes with two independent molecules (AandB) in the asymmetric unit. In each of the molecules, in both (I) and (II), an intramolecular N—H...N hydrogen bond forms anS(7) ring motif. The pyrimidine ring is inclined to the benzene ring by 42.25 (14)° in (I), and by 59.70 (16) and 62.18 (15)° in moleculesAandB, respectively, of compound (II). In the crystal of (I), molecules are linked by pairs of N—H...N hydrogen bonds, forming inversion dimers with anR22(8) ring motif. The dimers are linkedviabifurcated N—H...O and C—H...O hydrogen bonds, forming corrugated layers parallel to theacplane. In the crystal of (II), theAmolecules are linked through N—H...O and N—H...Cl hydrogen bonds, forming layers parallel to (100). TheBmolecules are also linked by N—H...O and N—H...Cl hydrogen bonds, also forming layers parallel to (100). The parallel layers ofAandBmolecules are linkedviaN—H...N hydrogen bonds, forming a three-dimensional structure.


Author(s):  
G. Vimala ◽  
N. Poomathi ◽  
P. T. Perumal ◽  
A. SubbiahPandi

The title compounds, C19H16ClNO5, (I), and C19H15Cl2NO5, (II), both crystallize in the monoclinic space groupP21/n. They differ essentially in the orientation of the methyl acetate group, with the C=O bond directed towards the NO2group in (I) but away from it in (II). In compound (I), the mean plane of the methyl acrylate unit is planar, with a maximum deviation of 0.0044 (2) Å for the methyl C atom, while in (II) this deviation is 0.0147 Å. The interplanar angles between the two aromatic rings are 74.87 (9) and 75.65 (2)° for compounds (I) and (II), respectively. In both compounds, the methyl acrylate and nitrovinyl groups each adopt anEconformation about the C=C bond. In the crystal of (I), molecules are linked by C—H...O hydrogen bonds forming chains along thebaxis. The chains are linkedviaC—H...Cl hydrogen bonds, forming sheets parallel to theabplane. The sheets are linkedviaC—H...π interactions, forming a three-dimensional structure. In the crystal of (II), molecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers with anR22(30) ring motif. The dimers are linkedviaC—H...O hydrogen bonds, forming sheets parallel to theacplane and enclosingR44(28) ring motifs. The sheets are linkedviaparallel slipped π–π interactions (intercentroid distances are bothca3.86 Å), forming a three-dimensional structure.


2014 ◽  
Vol 70 (9) ◽  
pp. o1036-o1037 ◽  
Author(s):  
J. V. Jovita ◽  
S. Sathya ◽  
G. Usha ◽  
R. Vasanthi ◽  
A. Ramanand

The title molecular salt, C6H9N2+·C4H5O6−·H2O, crystallized with two 2-amino-4-methylpyridin-1-ium cations, two L-(+)-tartaric acid monoanions [systematic name: (2R,3R)-3-carboxy-2,3-dihydroxypropanoate] and two water molecules in the asymmetric unit. In the crystal, the cations, anions and water molecules are linkedviaa number of O—H...O and N—H...O hydrogen bonds, and a C—H...O hydrogen bond, forming a three-dimensional structure


2016 ◽  
Vol 72 (8) ◽  
pp. 1171-1175 ◽  
Author(s):  
S. Subasri ◽  
Ajay Kumar Timiri ◽  
Nayan Sinha Barji ◽  
Venkatesan Jayaprakash ◽  
Viswanathan Vijayan ◽  
...  

The title compounds, C12H12N6O3S·H2O, (I), and C12H12ClN5OS, (II), are 2-[(4,6-diaminopyrimidin-2-yl)sulfanyl]acetamides. Compound (I) crystallized as a monohydrate. In both compounds, the molecules have a folded conformation, with the pyrimidine ring being inclined to the benzene ring by 56.18 (6)° in (I) and by 67.84 (6)° in (II). In both molecules, there is an intramolecular N—H...N hydrogen bond stabilizing the folded conformation. In (I), there is also a C—H...O intramolecular short contact, and in (II) an intramolecular N—H...Cl hydrogen bond is present. In the crystal of (I), molecules are linked by a series of N—H...O, O—H...O and O—H...N hydrogen bonds, forming undulating sheets parallel to the (100). The sheets are linkedviaan N—H...Owaterhydrogen bond, forming a three-dimensional network. In the crystal of (II), molecules are linked by a series of N—H...O, N—H...N and C—H...O hydrogen bonds, forming slabs parallel to (001).


IUCrData ◽  
2016 ◽  
Vol 1 (4) ◽  
Author(s):  
Abdelhanine Essaghouani ◽  
Younos Bouzian ◽  
El Mokhtar Essassi ◽  
Mohamed Saadi ◽  
Lahcen El Ammari

The title compound, C17H16N2O, consists of a benzodiazepin-2-one moiety substituted with a phenyl ring and an ethyl group. The seven-membered diazepine ring has a boat conformation and the fused benzene ring is nearly perpendicular to the phenyl ring, as indicated by the dihedral angle of 74.90 (8)°. The atoms of the ethyl group are disordered over two sets of sites, with a refined occupancy ratio of 0.603 (15):0.397 (15). In the crystal, molecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers. The dimers are linkedviaa further C—H...O hydrogen bond, forming layers parallel to (001), which are in turn linked by C—H...π interactions, forming a three-dimensional structure.


Author(s):  
Karim Chkirate ◽  
Sevgi Kansiz ◽  
Khalid Karrouchi ◽  
Joel T. Mague ◽  
Necmi Dege ◽  
...  

The asymmetric unit of the title compound, C20H20N4O·0.5H2O, contains two independent organic molecules (1 and 2) and a water molecule of crystallization. The two molecules differ primarily in the dihedral angles between the aromatic rings, which are 7.79 (7) and 29.89 (7)° in molecules 1 and 2, respectively. In each molecule there is intramolecular C—H...O hydrogen bond forming an S(6) ring motif. In molecule 1 there is an intramolecular N—H...π(pyrazole) interaction and an intramolecular C—H...π(pyrazole) interaction present. Molecule 1 is linked to molecule 2 by a C—H...π(benzene ring) interaction. An intramolecular N—H...N hydrogen bond and an intramolecular C—H...N hydrogen bond are also present in molecule 2. In the crystal, the three components are linked by Owater—H...N, N—H...Owater and N—H...N hydrogen bonds, forming chains along the [100] direction. The chains are linked by C—H...O and C—H...N hydrogen bonds, forming layers parallel to the ab plane. Finally, the layers are linked by C—H...π interactions, forming a three-dimensional structure.


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