scholarly journals Different supramolecular interactions mediated by Br atoms in the crystal structures of three anisole derivatives

2018 ◽  
Vol 74 (3) ◽  
pp. 283-288
Author(s):  
Robert Nestler ◽  
Anke Schwarzer ◽  
Tobias Gruber
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Building Blocks ◽  
Molecular Structures ◽  
Supramolecular Interactions ◽  
Π Interactions ◽  
Compound Ii

Three anisole building blocks featuring bis(hydroxymethyl) or bis(bromomethyl) pendants have been analyzed with regard to their molecular structures and packing behaviour. The compounds are ethyl 3,5-bis(hydroxymethyl)-4-methoxybenzoate, C12H16O5, (I), [5-bromo-3-(hydroxymethyl)-2-methoxyphenyl]methanol [or 4-bromo-2,6-bis(hydroxymethyl)anisole], C9H11BrO3, (II), and 5-bromo-1,3-bis(bromomethyl)-2-methoxybenzene [or 4-bromo-2,6-bis(bromomethyl)anisole], C9H9Br3O, (III). A typical supramolecular pattern involved C—H...π interactions generating molecular stacks, while π–π interactions were only observed in the absence of bromine, indicating a striking influence on the distances between adjacent aromatic moieties. When comparing bis(hydroxymethyl) compound (II) with bis(bromomethyl) compound (III), we found that the strong O—H...O hydrogen bonds in a zigzag arrangement in the first are replaced by C—H...Br interactions in the second without a change in the general packing.

scholarly journals Crystal structures of (E)-3-(furan-2-yl)-2-phenyl-N-tosylacrylamide and (E)-3-phenyl-2-(m-tolyl)-N-tosylacrylamide

2016 ◽  
Vol 72 (6) ◽  
pp. 797-800
Author(s):  
Dong Cheng ◽  
Xiangzhen Meng ◽  
Zeyuan Sheng ◽  
Shuangming Wang ◽  
Yuanyuan Duan ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Torsion Angle ◽  
Π Interactions ◽  
Compound Ii ◽  
Ring Motif

In the titleN-tosylacrylamide compounds, C20H17NO4S, (I), and C23H21NO3S, (II), the conformation about the C=C bond isE. The acrylamide groups, [–NH—C(=O)—C=C–], are almost planar, with the N—C—C=C torsion angle being −170.18 (14)° in (I) and −168.01 (17)° in (II). In (I), the furan, phenyl and 4-methylbenzene rings are inclined to the acrylamide mean plane by 26.47 (11), 69.01 (8) and 82.49 (9)°, respectively. In (II), the phenyl, 3-methylbenzene and 4-methylbenzene rings are inclined to the acrylamide mean plane by 11.61 (10), 78.44 (10) and 78.24 (10)°, respectively. There is an intramolecular C—H...π interaction present in compound (II). In the crystals of both compounds, molecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with anR22(8) ring motif. In (I), the dimers are reinforced by C—H...O hydrogen bonds and linked by C—H...π interactions, forming chains along [011]. In the crystal of (II), the dimers are linkedviaC—H...O hydrogen bonds, forming chains along [100]. The chains are further linked by C—H...π interactions, forming layers parallel to (010).

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 structures of the synthetic intermediate 3-[(6-chloro-7H-purin-7-yl)methyl]cyclobutan-1-one, and of two oxetanocin derivatives: 3-[(6-chloro-8,9-dihydro-7H-purin-7-yl)methyl]cyclobutan-1-ol and 3-[(6-chloro-9H-purin-9-yl)methyl]cyclobutan-1-ol

2019 ◽  
Vol 75 (6) ◽  
pp. 732-737
Author(s):  
Ayat Yaseen ◽  
Muhammad Murtaza Hassan ◽  
Edward Lee-Ruff ◽  
Gerald F. Audette
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Nucleoside Analogs ◽  
Supramolecular Framework ◽  
Π Interactions ◽  
Facial Selectivity ◽  
Purine Ring ◽  
Compound Ii ◽  
Synthetic Intermediate ◽  
Ring Motif

The crystal structures of an intermediate, C10H9ClN4O, 3-[(6-chloro-7H-purin-7-yl)methyl]cyclobutan-1-one (I), and two N-7 and N-9 regioisomeric oxetanocin nucleoside analogs, C10H13ClN4O, 3-[(6-chloro-8,9-dihydro-7H-purin-7-yl)methyl]cyclobutan-1-ol (II) and C10H11ClN4O, 3-[(6-chloro-9H-purin-9-yl)methyl]cyclobutan-1-ol (IV), are reported. The crystal structures of the nucleoside analogs confirmed the reduction of the N-7- and N-9-substituted cyclobutanones with LiAl(OtBu)3 to occur with facial selectivity, yielding cis-nucleosides analogs similar to those found in nature. Reduction of the purine ring of the N-7 cyclobutanone to a dihydropurine was observed for compound (II) but not for the purine ring of the N-9 cyclobutanone on formation of compound (IV). In the crystal of (I), molecules are linked by a weak Cl...O interaction, forming a 21 helix along [010]. The helices are linked by offset π–π interactions [intercentroid distance = 3.498 (1) Å], forming layers parallel to (101). In the crystal of (II), molecules are linked by pairs of O—H...N hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif. The dimers are linked by O—H...N hydrogen bonds, forming chains along [001], which in turn are linked by C—H...π and offset π–π interactions [intercentroid distance = 3.509 (1) Å], forming slabs parallel to the ac plane. In the crystal of (IV), molecules are linked by O—H...N hydrogen bonds, forming chains along [101]. The chains are linked by C—H...N and C—H...O hydrogen bonds and C—H...π and offset π–π interactions [intercentroid distance = 3.364 (1) Å], forming a supramolecular framework.

scholarly journals Steric repulsion and supramolecular assemblies via a two-dimensional plate by C—H...O hydrogen bonds in two closely related 2-(benzofuran-2-yl)-2-oxoethyl benzoates

2017 ◽  
Vol 73 (8) ◽  
pp. 1227-1231
Author(s):  
Li Yee Then ◽  
C. S. Chidan Kumar ◽  
Huey Chong Kwong ◽  
Yip-Foo Win ◽  
Siau Hui Mah ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Molecular Structures ◽  
Steric Repulsion ◽  
Two Dimensional ◽  
Compound I ◽  
Intermolecular Hydrogen Bonds ◽  
Π Interactions ◽  
Phenyl Rings ◽  
Compound Ii

2-(Benzofuran-2-yl)-2-oxoethyl 2-chlorobenzoate, C17H11ClO4 (I), and 2-(benzofuran-2-yl)-2-oxoethyl 2-methoxybenzoate, C18H14O5 (II), were synthesized under mild conditions. Their chemical and molecular structures were analyzed by spectroscopic and single-crystal X-ray diffraction studies, respectively. These compounds possess different ortho-substituted functional groups on their phenyl rings, thus experiencing extra steric repulsion force within their molecules as the substituent changes from 2-chloro (I) to 2-methoxy (II). The crystal packing of compound (I) depends on weak intermolecular hydrogen bonds and π–π interactions. Molecules are related by inversion into centrosymmetric dimers via C—H...O hydrogen bonds, and further strengthened by π–π interactions between furan rings. Conversely, molecules in compound (II) are linked into alternating dimeric chains propagating along the [101] direction, which develop into a two-dimensional plate through extensive intermolecular hydrogen bonds. These plates are further stabilized by π–π and C—H...π interactions.

scholarly journals Crystal structures of threeN-(3-acetylphenyl)quinoline-2-carboxamides

2017 ◽  
Vol 73 (6) ◽  
pp. 804-808
Author(s):  
Diana Peña-Solórzano ◽  
Burkhard König ◽  
Cesar A. Sierra ◽  
Cristian Ochoa-Puentes
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Ring System ◽  
Molecular Structures ◽  
Dihedral Angles ◽  
Stacking Interactions ◽  
Quinoline Ring ◽  
Π Interactions ◽  
Bond Forming

In the title compounds,N-(5-acetyl-2-methylphenyl)quinoline-2-carboxamide [C19H16N2O2, (I)],N-(5-acetyl-2-bromophenyl)quinoline-2-carboxamide [C18H13BrN2O2, (II)] andN-(5-acetyl-2-ethynylphenyl)quinoline-2-carboxamide [C20H14N2O2, (III)], the quinoline ring system is essentially planar and forms a dihedral angles of 3.68 (5) (I), 5.59 (7) (II) and 1.87 (6)° (III) with the acetyl-substituted ring. The molecular structures of (I) and (III) each feature an intramolecular N—H...N hydrogen bond, forming anS(5) ring, while in (II) an intramolecular bifurcated N—H...(N,Br) hydrogen bond forms twoS(5) rings. In the crystals, weak C—H...O hydrogen bonds link molecules of (I) intoC(7) chains long [010], molecules of (II) into chains ofR22(8) rings along [110] and molecules of (III) intoC(8) chains along [010]. In (I), there are no significant π–π stacking interactions under 4 Å, but in both (II) and (III), π–π interactions link the weak hydrogen-bonded chains into layers parallel to (001) [centroid–centroid disttances of 3.748 (1) Å in (II) and 3.577 (1), 3.784 (1) and 3.780 (1) Å in (III)].

scholarly journals Crystal structures of 3-fluoro-N-[2-(trifluoromethyl)phenyl]benzamide, 3-bromo-N-[2-(trifluoromethyl)phenyl]benzamide and 3-iodo-N-[2-(trifluoromethyl)phenyl]benzamide

2016 ◽  
Vol 72 (6) ◽  
pp. 819-823 ◽  
Author(s):  
P. A. Suchetan ◽  
E. Suresha ◽  
S. Naveen ◽  
N. K. Lokanath
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Asymmetric Unit ◽  
Compound I ◽  
Axis Direction ◽  
Π Interactions ◽  
Benzene Rings ◽  
Independent Molecules ◽  
Compound Ii

In the title compounds, C14H9F4NO, (I), C14H9BrF3NO, (II), and C14H9F3INO, (III), the two benzene rings are inclined to one another by 43.94 (8)° in moleculeAand 55.66 (7)° in moleculeBof compound (I), which crystallizes with two independent molecules in the asymmetric unit, but by only 10.40 (12)° in compound (II) and 12.5 (2)° in compound (III). In the crystals of all three compounds, N—H...O hydrogen bonds link the molecules to form chains propagating along thea-axis direction for (I), and along theb-axis direction for (II) and (III). In the crystal of (I), –A–B–A–B– chains are linked by C—H...O hydrogen bonds, forming layers parallel to (010). Within the layers there are weak offset π–π interactions present [intercentroid distances = 3.868 (1) and 3.855 (1) Å]. In the crystals of (II) and (III), the chains are linkedviashort halogen–halogen contacts [Br...Br = 3.6141 (4) Å in (II) and I...I = 3.7797 (5) Å in (III)], resulting in the formation of ribbons propagating along theb-axis direction.

scholarly journals Crystal structures of 1-(4-chlorophenyl)-2-(diphenylphosphoryl)ethan-1-one and 1-(diphenylphosphoryl)-3,3-dimethylbutan-2-one

2015 ◽  
Vol 71 (5) ◽  
pp. 523-527
Author(s):  
Erin G. Leach ◽  
Alyssa A. Kulesza ◽  
Richard J. Staples ◽  
Shannon M. Biros
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Resonant Scattering ◽  
Arbuzov Reaction ◽  
Π Interactions ◽  
The Absolute ◽  
Compound Ii ◽  
Absolute Structure

The title compounds, C20H16ClO2P, (I), and C18H21O2P, (II), were synthesizedviaan Arbuzov reaction between an α-bromoketone and isopropoxydiphenylphosphane. In the crystals of both compounds, molecules are linkedviabifurcated C—H...(O,O) hydrogen bonds, forming chains propagating along [100] for (I) and along [010] for (II). The chains are linkedviaC—H...π interactions, leading to the formation of sheets lying parallel to (010) for (I) and (001) for (II). The absolute structure of compound (II) was determined by resonant scattering [Flack parameter = 0.088 (14)].

scholarly journals The crystal structures of three pyrazine-2,5-dicarboxamides: three-dimensional supramolecular structures

2017 ◽  
Vol 73 (5) ◽  
pp. 729-734
Author(s):  
Dilovan S. Cati ◽  
Helen Stoeckli-Evans
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Supramolecular Structure ◽  
Three Dimensional ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Inversion Symmetry ◽  
Compound I ◽  
Space Group ◽  
Π Interactions

The complete molecules of the title compounds,N2,N5-bis(pyridin-2-ylmethyl)pyrazine-2,5-dicarboxamide, C18H16N6O2(I), 3,6-dimethyl-N2,N5-bis(pyridin-2-ylmethyl)pyrazine-2,5-dicarboxamide, C20H20N6O2(II), andN2,N5-bis(pyridin-4-ylmethyl)pyrazine-2,5-dicarboxamide, C18H16N6O2(III), are generated by inversion symmetry, with the pyrazine rings being located about centres of inversion. Each molecule has an extended conformation with the pyridine rings inclined to the pyrazine ring by 89.17 (7)° in (I), 75.83 (8)° in (II) and by 82.71 (6)° in (III). In the crystal of (I), molecules are linked by N—H...N hydrogen bonds, forming layers lying parallel to thebcplane. The layers are linked by C—H...O hydrogen bonds, forming a three-dimensional supramolecular structure. In the crystal of (II), molecules are also linked by N—H...N hydrogen bonds, forming layers lying parallel to the (10-1) plane. As in (I), the layers are linked by C—H...O hydrogen bonds, forming a three-dimensional supramolecular structure. In the crystal of (III), molecules are again linked by N—H...N hydrogen bonds, but here form corrugated sheets lying parallel to thebcplane. Within the sheets, neighbouring pyridine rings are linked by offset π–π interactions [intercentroid distance = 3.739 (1) Å]. The sheets are linked by C—H...O hydrogen bonds, forming a three-dimensional supramolecular structure. Compound (I) crystallizes in the monoclinic space groupP21/c. Another monoclinic polymorph, space groupC2/c, has been reported on by Cockrielet al.[Inorg. Chem. Commun.(2008),11, 1–4]. The molecular structures of the two polymorphs are compared.

scholarly journals Crystal structures and Hirshfeld surface analysis of 2-(adamantan-1-yl)-5-(4-fluorophenyl)-1,3,4-oxadiazole and 2-(adamantan-1-yl)-5-(4-chlorophenyl)-1,3,4-oxadiazole

2019 ◽  
Vol 75 (5) ◽  
pp. 611-615 ◽  
Author(s):  
Lamya H. Al-Wahaibi ◽  
Aisha Alsfouk ◽  
Ali A. El-Emam ◽  
Olivier Blacque
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Surface Analysis ◽  
Interplanar Distance ◽  
Relative Orientation ◽  
Membered Ring ◽  
Hirshfeld Surface ◽  
Molecular Structures ◽  
Π Interactions ◽  
Hybrid Compounds

The crystal structures of the title adamantane-oxadiazole hybrid compounds, C18H19FN2O (I) and C18H19ClN2O (II), are built up from an adamantane unit and a halogenophenyl ring, [X = F (I), Cl (II)], in position 5 on the central 1,3,4-oxadiazole unit. The molecular structures are very similar, only the relative orientation of the halogenophenyl ring in comparison with the central five-membered ring differs slightly. In the crystals of both compounds, molecules are linked by pairs of C—H...N hydrogen bonds, forming inversion dimers with R 2 2(12) ring motifs. In (I) the dimers are connected by C—H...F interactions, forming slabs lying parallel to the bc plane. In (II), the dimers are linked by C—H...π and offset π–π interactions [interplanar distance = 3.4039 (9) Å], forming layers parallel to (10\overline{1}).

scholarly journals Crystal structures of the dioxane hemisolvates ofN-(7-bromomethyl-1,8-naphthyridin-2-yl)acetamide and bis[N-(7-dibromomethyl-1,8-naphthyridin-2-yl)acetamide]

2017 ◽  
Vol 73 (10) ◽  
pp. 1409-1413 ◽  
Author(s):  
Robert Rosin ◽  
Wilhelm Seichter ◽  
Monika Mazik
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Lone Electron Pair ◽  
Electron Pair ◽  
Three Dimensional ◽  
Supramolecular Network ◽  
Halogen Bonds ◽  
Host Interactions ◽  
Compound Ii ◽  
Noncovalent Bonding

The syntheses and crystal structures ofN-(7-bromomethyl-1,8-naphthyridin-2-yl)acetamide dioxane hemisolvate, C11H10BrN3O·0.5C4H8O2, (I), and bis[N-(7-dibromomethyl-1,8-naphthyridin-2-yl)acetamide] dioxane hemisolvate, 2C11H9Br2N3O·0.5C4H8O2, (II), are described. The molecules adopt a conformation with the N—H hydrogen pointing towards the lone electron pair of the adjacent naphthyridine N atom. The crystals of (I) are stabilized by a three-dimensional supramolecular network comprising N—H...N, C—H...N and C—H...O hydrogen bonds, as well as C—Br...π halogen bonds. The crystals of compound (II) are stabilized by a three-dimensional supramolecular network comprising N—H...N, C—H...N and C—H...O hydrogen bonds, as well as C—H...π contacts and C—Br...π halogen bonds. The structure of the substituent attached in the 7-position of the naphthyridine skeleton has a fundamental influence on the pattern of intermolecular noncovalent bonding. While the Br atom of (I) participates in weak C—Br...Oguestand C—Br...π contacts, the Br atoms of compound (II) are involved in host–host interactionsviaC—Br...O=C, C—Br...N and C—Br...π bonding.

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