scholarly journals TwoN-(2-phenylethyl)nitroaniline derivatives as precursors for slow and sustained nitric oxide release agents

2016 ◽  
Vol 72 (5) ◽  
pp. 405-410 ◽  
Author(s):  
Alec R. Badour ◽  
John A. Wisniewski ◽  
Dillip K. Mohanty ◽  
Philip J. Squattrito
Keyword(s):  
Nitric Oxide ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Molecular Conformation ◽  
Therapeutic Interventions ◽  
Secondary Amines ◽  
Asymmetric Unit ◽  
High Concentration ◽  
Nitric Oxide Release ◽  
Π Interactions

Notwithstanding its simple structure, the chemistry of nitric oxide (NO) is complex. As a radical, NO is highly reactive. NO also has profound effects on the cardiovascular system. In order to regulate NO levels, direct therapeutic interventions include the development of numerous NO donors. Most of these donors release NO in a single high-concentration burst, which is deleterious.N-Nitrosated secondary amines release NO in a slow, sustained, and rate-tunable manner. Two new precursors to sustained NO-releasing materials have been characterized.N-[2-(3,4-Dimethoxyphenyl)ethyl]-2,4-dinitroaniline, C16H17N3O6, (I), crystallizes with one independent molecule in the asymmetric unit. The adjacent amine and nitro groups form an intramolecular N—H...O hydrogen bond. Theanticonformation about the phenylethyl-to-aniline C—N bond leads to the planes of the arene and aniline rings being approximately perpendicular. Molecules are linked into dimers by weak intermolecular N—H...O hydrogen bonds such that each amine H atom participates in a three-center interaction with two nitro O atoms. The dimers pack so that the arene rings of adjacent molecules are not parallel and π–π interactions do not appear to be favored.N-(4-Methylsulfonyl-2-nitrophenyl)-L-phenylalanine, C16H16N2O6S, (II), with an optically active center, also crystallizes with one unique molecule in the asymmetric unit. The L enantiomer was establishedviathe configuration of the starting material and was confirmed by refinement of the Flack parameter. As in (I), there is an intramolecular N—H...O hydrogen bond between adjacent amine and nitro groups. The conformation of the molecule is such that the arene rings display a dihedral angle ofca60°. Unlike (I), molecules are not linkedviaintermolecular N—H...O hydrogen bonds. Rather, the carboxylic acid H atom forms a classic, approximately linear, O—H...O hydrogen bond with a sulfone O atom. Pairs of molecules related by twofold rotation axes are linked into dimers by two such interactions. The packing pattern features a zigzag arrangement of the arene rings without apparent π–π interactions. These structures are compared with reported analogues, revealing significant differences in molecular conformation, intermolecular interactions, and packing that result from modest changes in functional groups. The structures are discussed in terms of potential NO-release capability.

scholarly journals Crystal structures of three 6-aryl-2-(4-chlorobenzyl)-5-[(1H-indol-3-yl)methyl]imidazo[2,1-b][1,3,4]thiadiazoles

2020 ◽  
Vol 76 (1) ◽  
pp. 18-24
Author(s):  
Sadashivamurthy Shamanth ◽  
Kempegowda Mantelingu ◽  
Haruvegowda Kiran Kumar ◽  
Hemmige S. Yathirajan ◽  
Sabine Foro ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
Compound I ◽  
Π Interactions ◽  
Reductive Condensation ◽  
Independent Molecules ◽  
Compound Ii

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.

scholarly journals Crystal structure of 2-[(E)-4-benzyloxy-2-hydroxybenzylidene]-N-cyclohexylhydrazinecarbothioamide acetonitrile hemisolvate

2014 ◽  
Vol 70 (9) ◽  
pp. o987-o988 ◽  
Author(s):  
N. R. Sajitha ◽  
M. Sithambaresan ◽  
M. R. Prathapachandra Kurup
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Double Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Molecular Conformation ◽  
Solvent Molecule ◽  
Asymmetric Unit ◽  
Compound C ◽  
Independent Molecules

The asymmetric unit of the title compound, C21H25N3O2S·0.5C2H3N, contains two independent molecules with almost similar structural properties along with a solvent molecule of acetonitrile. The compound exists in theEconformation with respect to the azomethine C=N double bond. The hydrazinecarbothioamide moieties in both independent molecules are almost planar [maximum deviations of 0.013 (2) and 0.007 (2) Å]. The molecular conformation is stabilized in each case by an intramolecular N—H...N hydrogen bond. In the crystal, pairs of N—H...S hydrogen bonds link each of the independent molecules into inversion dimers. The dimers are interconnected by means of three C—H...π interactions.

scholarly journals 3-Acetyl-1-(2,3-dichlorophenyl)thiourea

2012 ◽  
Vol 68 (8) ◽  
pp. o2353-o2353
Author(s):  
B. Thimme Gowda ◽  
Sabine Foro ◽  
Sharatha Kumar
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Molecular Conformation ◽  
Asymmetric Unit ◽  
Compound C

In the crystal structure of the title compound, C9H8Cl2N2OS, there are two molecules in the asymmetric unit which are connected by a pair of N—H...S hydrogen bonds. An intramolecular N—H...O hydrogen bond stabilizes the molecular conformation of each molecule.

scholarly journals 4-[(5-Bromo-2-hydroxybenzylidene)amino]-3-ethyl-1H-1,2,4-triazole-5(4H)-thione

2014 ◽  
Vol 70 (8) ◽  
pp. o881-o882
Author(s):  
Cai-Xia Yuan ◽  
Shu-Fen Lan ◽  
Xin-Yu Liu ◽  
Miao-Li Zhu
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Π Interactions ◽  
Compound C ◽  
Centroid Distance ◽  
Benzene Rings ◽  
Independent Molecules

The title compound, C11H11BrN4OS, crystallized as a racemic twin with two symmetry-independent molecules in the asymmetric unit. The dihedral angles between the benzene and triazole rings of the two independent molecules are 56.41 (18) and 54.48 (18)°. An intramolecular O—H...N hydrogen bond occurs in each molecule. In the crystal, pairs of symmetry-independent molecules are linked by pairs of almost linear N—H...S hydrogen bonds, forming cyclic dimers characterized by anR22(8) motif. There are weak π–π interactions between the benzene rings of symmetry-independent molecules, with a centroid–centroid distance of 3.874 (3) Å.

scholarly journals The crystal structures of 6′-(4-chlorophenyl)- and 6′-(4-methoxyphenyl)-6a′-nitro-6a′,6b′,7′,9′,10′,12a′-hexahydro-2H,6′H,8′H-spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizin]-2-one

2019 ◽  
Vol 75 (2) ◽  
pp. 218-222 ◽  
Author(s):  
S. Syed Abuthahir ◽  
M. NizamMohideen ◽  
V. Viswanathan ◽  
D. Velmurugan ◽  
J. Nagasivarao
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Supramolecular Structure ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
Π Interactions ◽  
Independent Molecules ◽  
Intramolecular Hydrogen ◽  
Compound Ii ◽  
Ring Motif

In the title compounds, C32H25ClN2O4 (I) and C33H28N2O5 (II), the six-membered pyran and piperidine rings adopt envelope and chair conformations, respectively. The five-membered pyrrolidine rings adopt twist conformations. Compound (II) crystallizes with two independent molecules (A and B) in the asymmetric unit. In all three molecules there is a C—H...O intramolecular hydrogen bond present enclosing an S(7) ring motif. In (I), both oxygen atoms of the nitro group are disordered, while in (II) the methoxybenzene group is disordered in molecule B. The geometries were regularized by soft restraints. In the crystal of (I), molecules are linked by C—H...O hydrogen bonds, forming chains along [010]. The chains are linked by C—H...Cl hydrogen bonds, forming layers parallel to (10\overline{1}). Within the layer there are C—H...π interactions present. In the crystal of (II), the A and B molecules are linked via C—H...O hydrogen bonds, forming a square four-membered A–B–A–B unit. These units are linked by a number of C—H...π interactions, forming a three-dimensional supramolecular structure.

scholarly journals Crystal structure of difluorido{2-[(4-hydroxyphenyl)diazenyl]-3,5-dimethylpyrrolido}boron

2018 ◽  
Vol 74 (5) ◽  
pp. 743-746
Author(s):  
Huixiao Feng ◽  
Zhenming Yin
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Asymmetric Unit ◽  
One Dimensional ◽  
Π Interactions ◽  
Independent Molecules

The asymmetric unit of the title azopyrrole-BF2 complex, C12H12BF2N3O, contains two independent molecules, which are linked by an O—H...O hydrogen bond. The dimers are further assembled into a one-dimensional ladder-like structure through O—H...F hydrogen bonds and stabilized by π–π interactions. The ladders are further linked by C—H...π contacts.

scholarly journals Crystal structures of 2-[3,5-bis(bromomethyl)-2,4,6-triethylbenzyl]isoindoline-1,3-dione and 2-{5-(bromomethyl)-3-[(1,3-dioxoisoindolin-2-yl)methyl]-2,4,6-triethylbenzyl}isoindoline-1,3-dione

2021 ◽  
Vol 77 (9) ◽  
Author(s):  
Manuel Stapf ◽  
Betty Leibiger ◽  
Anke Schwarzer ◽  
Monika Mazik
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Molecular Conformation ◽  
Halogen Bond ◽  
Asymmetric Unit ◽  
Space Group ◽  
Π Interactions ◽  
Hydrogen Bonding Interactions

The title compounds, C23H25Br2NO2 (1) and C31H29BrN2O4 (2), crystallize in the space group P21/n with two (1-A and 1-B) and one molecules, respectively, in the asymmetric unit of the cell. The molecular conformation of these compounds is stabilized by intramolecular C—H...O hydrogen bonds and C—H...N or C—H...π interactions. The crystal structure of 1 features a relatively strong Br...O=C halogen bond, which is not observed in the case of 2. Both crystal structures are characterized by the presence of C—H...Br hydrogen bonds and numerous intermolecular C—H...O hydrogen-bonding interactions.

scholarly journals A series ofN-(2-phenylethyl)nitroaniline derivatives as precursors for slow and sustained nitric oxide release agents

2013 ◽  
Vol 69 (11) ◽  
pp. 1383-1389 ◽  
Author(s):  
Colin B. Wade ◽  
Dillip K. Mohanty ◽  
Philip J. Squattrito ◽  
Nicholas J. Amato ◽  
Kristin Kirschbaum
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Nitro Group ◽  
Molecular Conformation ◽  
Cyano Group ◽  
The Other ◽  
Monoclinic Space Group ◽  
Asymmetric Unit ◽  
Intermolecular Hydrogen Bonds ◽  
Ethyl Group

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. Theanticonformation 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 ananticonformation as in (I), the other isgauche, with the result that the pendant phenyl rings are not parallel. The amine group that is part of thegaucheconformation 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 ofca3.4 Å of the parallelantiphenyl 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 sameanticonformation about the ethyl group as in (I), but crystallize in the higher-symmetry monoclinic space groupP21/n. The molecules are linked into dimersviaN—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 isgauche, 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 thecaxis, with the aniline rings mostly parallel and separated byca3.7 Å. Taken together, these structures demonstrate that modest changes in functional groups cause significant differences in molecular conformation, intermolecular interactions and packing.

scholarly journals Crystal structure of (E)-4-hydroxy-N′-(3-methoxybenzylidene)benzohydrazide

2016 ◽  
Vol 72 (9) ◽  
pp. 1339-1342 ◽  
Author(s):  
Suchada Chantrapromma ◽  
Patcharawadee Prachumrat ◽  
Pumsak Ruanwas ◽  
Nawong Boonnak ◽  
Mohammad B. Kassim
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Methoxy Group ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Π Interactions ◽  
Compound C ◽  
Benzene Rings ◽  
Independent Molecules

The title compound, C15H14N2O3, crystallizes with two independent molecules (AandB) in the asymmetric unit that differ in the orientation of the 3-methoxyphenyl group with respect to the methylidenebenzohydrazide unit. The dihedral angles between the two benzene rings are 24.02 (10) and 29.30 (9)° in moleculesAandB, respectively. In moleculeA, the methoxy group is twisted slightly relative to its bound benzene ring, with a Cmethyl—O—C—C torsion angle of 14.2 (3)°, whereas it is almost co-planar in moleculeB, where the corresponding angle is −2.4 (3)°. In the crystal, the molecules are linked by N—H...O, O—H...N and O—H...O hydrogen bonds, as well as by weak C—H...O interactions, forming sheets parallel to thebcplane. The N—H...O hydrogen bond and weak C—H...O interaction link different molecules (A...B) whereas both O—H...N and O—H...O hydrogen bonds link like molecules (A...A) and (B...B). Pairs of inversion-relatedBmolecules are stacked approximately along theaaxis by π–π interactions in which the distance between the centroids of the 3-methoxyphenyl rings is 3.5388 (12) Å. TheBmolecules also participate in weak C—H...π interactions between the 4-hydroxyphenyl and the 3-methoxyphenyl rings.

scholarly journals Crystal structure of 4-amino-5-fluoro-2-oxo-2,3-dihydropyrimidin-1-ium 3-hydroxypyridine-2-carboxylate

2014 ◽  
Vol 70 (11) ◽  
pp. 328-330 ◽  
Author(s):  
Ammasai Karthikeyan ◽  
Packianathan Thomas Muthiah ◽  
Franc Perdih
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Amine Group ◽  
Asymmetric Unit ◽  
Π Interactions ◽  
Ring Motif

The asymmetric unit of the title salt, C4H5FN3O+·C6H4NO3−, contains one 4-amino-5-fluoro-2-oxo-2,3-dihydropyrimidin-1-ium (5-fluorocytosinium, 5FC) cation and a 3-hydroxypicolinate (3HAP) anion. The 4-amino-5-fluoro-2-oxo-2,3-dihydropyrimidine molecule is protonated at one of the pyrimidine N atoms. The typical intramolecular N—H...F and O—H...OS(5) andS(6) hydrogen-bond ring motifs are observed in the cations and anions. The protonated N atom and 2-amine group of the 5FC cation interact with the 3HPA anion through a pair of nearly parallel N—H...O hydrogen bonds, forming a robustR22(8) ring motif. The ions are further linked by N—H...N, O—H...O, N—H...O and C—H...O hydrogen bonds, generatingR22(7),R33(12) andR65(18) ring motifs, respectively, leading to supramolecular wave-like sheets parallel to (010). The crystal structure is further stabilized by C—H...π interactions, generating a three-dimensional architecture.

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