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 Structure of Equilenin at 100 K: an estrone-related steroid

2017 ◽  
Vol 73 (8) ◽  
pp. 1223-1226
Author(s):  
Christopher S. Frampton ◽  
David D. MacNicol
Keyword(s):  
Hydrogen Bonds ◽  
Resonant Scattering ◽  
Methyl Group ◽  
Axis Direction ◽  
Envelope Conformation ◽  
The Absolute ◽  
Absolute Structure

The structure of the estrone-related steroid, Equilenin, C18H18O2 (systematic name 3-hydroxy-13-methyl-11,12,13,14,15,16-hexahydrocyclopenta[a]phenanthren-17-one), has been determined at 100 K. The crystals are orthorhombic, P212121, and the absolute structure of the molecule in the crystal has been determined by resonant scattering [Flack parameter = −0.05 (4)]. The C atoms of the A and B rings are almost coplanar, with an r.m.s. deviation from planarity of 0.0104 Å. The C ring has a sofa conformation, while the D ring has an envelope conformation with the methine C atom as the flap. The keto O atom and the methyl group are translated 0.78 and 0.79 Å, respectively, from the equivalent positions on 17β-estrone. In the crystal, molecules are linked by O—H...O hydrogen bonds, forming chains parallel to the c-axis direction.

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 The crystal structures of 3-O-benzyl-1,2-O-isopropylidene-5-O-methanesulfonyl-6-O-triphenylmethyl-α-D-glucofuranose and its azide displacement product

2018 ◽  
Vol 74 (6) ◽  
pp. 862-867
Author(s):  
Zane Clarke ◽  
Evan Barnes ◽  
Kate L. Prichard ◽  
Laura J. Mares ◽  
Jack K. Clegg ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Resonant Scattering ◽  
Azido Group ◽  
Supramolecular Framework ◽  
Substitution Product ◽  
Axis Direction ◽  
Π Interactions ◽  
Leaving Groups ◽  
Glucose Derivatives

The effect of different leaving groups on the substitutionversuselimination outcomes with C-5 D-glucose derivatives was investigated. The stereochemical configurations of 3-O-benzyl-1,2-O-isopropylidene-5-O-methanesulfonyl-6-O-triphenylmethyl-α-D-glucofuranose, C36H38O8S (3) [systematic name: 1-[(3aR,5R,6S,6aR)-6-benzyloxy-2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxol-5-yl)-2-(trityloxy)ethyl methanesulfonate], a stable intermediate, and 5-azido-3-O-benzyl-5-deoxy-1,2-O-isopropylidene-6-O-triphenylmethyl-β-L-idofuranose, C35H35N3O5(4) [systematic name: (3aR,5S,6S,6aR)-5-[1-azido-2-(trityloxy)ethyl]-6-benzyloxy-2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxole], a substitution product, were examined and the inversion of configuration for the azido group on C-5 in4was confirmed. The absolute structures of the molecules in the crystals of both compounds were confirmed by resonant scattering. In the crystal of3, neighbouring molecules are linked by C—H...O hydrogen bonds, forming chains along theb-axis direction. The chains are linked by C—H...π interactions, forming layers parallel to theabplane. In the crystal of4, molecules are also linked by C—H...O hydrogen bonds, forming this time helices along thea-axis direction. The helices are linked by a number of C—H...π interactions, forming a supramolecular framework.

scholarly journals Crystal structure of 7β-hydroxyroyleanone isolated fromTaxodium ascendens(B.)

2017 ◽  
Vol 73 (10) ◽  
pp. 1414-1416
Author(s):  
Shicheng Xu ◽  
Xinhua Ma ◽  
Ruifang Ke ◽  
Shihao Deng ◽  
Xinzhou Yang ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Resonant Scattering ◽  
Acta Cryst ◽  
Space Group ◽  
Compound C ◽  
The Absolute ◽  
Absolute Structure

The title compound, C20H28O4[systematic name: (4bS,8aS,10S)-3,10-dihydroxy-2-isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octahydrophenanthrene-1,4-dione], is an abietane-type diterpene, which was isolated fromTaxodium ascendens(B.). The compound crystallizes in the chiral space groupP21, but it was not possible to determine the absolute structure of the molecule in the crystal by resonant scattering. The molecular structure is stabilized by two intramolecular O—H...O hydrogen bonds, enclosingS(5) andS(6) ring motifs. In the crystal, molecules are linked by O—H...O and C—H...O hydrogen bonds, forming chains along the [010] direction. The crystal structure of the 10Rstereoisomer of the title compound, isolated from the roots ofPremna obtusifolia(Verbenaceae), has been reported. It crystallized in the chiral space groupP212121, and the absolute structure was determined as (4bS,8aS,10R), by resonant scattering using CuKα radiation [Razaket al.(2010).Acta Cryst.E66, o1566–o1567].

scholarly journals Crystal structure of (R)-N-benzyl-1-phenylethanaminium (R)-4-chloromandelate

2014 ◽  
Vol 70 (12) ◽  
pp. o1223-o1224
Author(s):  
Yangfeng Peng ◽  
Sohrab Rohani ◽  
Paul D. Boyle ◽  
Quan He
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Absolute Configuration ◽  
Three Dimensional ◽  
Resonant Scattering ◽  
Π Interactions ◽  
Two Component ◽  
Phenyl Rings ◽  
The Absolute ◽  
Molecular Salt

The absolute configuration of the title molecular salt, C15H18N+·C8H6ClO3−, has been confirmed by resonant scattering. In the (R)-N-benzyl-1-phenyl-ethylammonium cation, the phenyl rings are inclined to one another by 44.65 (7)°. In the crystal, the (R)-4-chloromandelate anions are linkedviaO—H...O hydrogen bonds and bridged by N—H...O hydrogen bonds involving the cations, forming chains along [010]. There are C—H...O hydrogen bonds present within the chains, which are linkedviaC—H...π interactions and a short Cl...Cl interaction [3.193 (1) Å] forming a three-dimensional framework. The structure was refined as a two-component inversion twin giving a Flack parameter of 0.05 (4).

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 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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