Similarities and differences in the crystal packing of halogen-substituted indole derivatives

2018 ◽  
Vol 74 (4) ◽  
pp. 376-384 ◽  
Author(s):  
Rahul Shukla ◽  
Paramveer Singh ◽  
Piyush Panini ◽  
Deepak Chopra
Keyword(s):  
Quantum Theory ◽  
Crystal Structures ◽  
Crystal Packing ◽  
Topological Analysis ◽  
Indole Derivatives ◽  
Π Interactions ◽  
Supramolecular Motifs ◽  
Exchange Repulsion ◽  
Similarities And Differences

The role of different intermolecular interactions in the crystal structures of halogen-substituted indoles which are fused with six-membered or seven-membered cyclic rings is investigated here. Several crystal structures show isostructural characteristics due to the presence of similar supramolecular motifs. In the absence of any strong hydrogen bonds, the molecular packing of reported structures is primarily stabilized by the presence of non-classical N—H...π and C—H...π interactions in addition to C—H...X (X = F/Cl/Br) interactions. The nature and energetics of primary and secondary dimeric motifs are partitioned into the electrostatics, polarization, dispersion and exchange–repulsion components using the PIXEL method. Short and directional N—H...π interactions are further explored by a topological analysis of the electron density based on quantum theory of atoms in molecules.

scholarly journals Crystal structures of four indole derivatives as possible cannabinoid allosteric antagonists

2015 ◽  
Vol 71 (6) ◽  
pp. 654-659 ◽  
Author(s):  
Jamie R. Kerr ◽  
Laurent Trembleau ◽  
John M. D. Storey ◽  
James L. Wardell ◽  
William T. A. Harrison
Keyword(s):  
Hydrogen Bond ◽  
Crystal Structures ◽  
Intermolecular Interaction ◽  
Ring System ◽  
Consistent Pattern ◽  
Indole Derivatives ◽  
Π Interactions

The crystal structures of four indole derivatives with various substituents at the 2-, 3- and 5-positions of the ring system are described, namely, ethyl 3-(5-chloro-2-phenyl-1H-indol-3-yl)-3-phenylpropanoate, C25H22ClNO2, (I), 2-bromo-3-(2-nitro-1-phenylethyl)-1H-indole, C16H13BrN2O2, (II), 5-methoxy-3-(2-nitro-1-phenylethyl)-2-phenyl-1H-indole, C23H20N2O3, (III), and 5-chloro-3-(2-nitro-1-phenylethyl)-2-phenyl-1H-indole, C22H17ClN2O2, (IV). The dominant intermolecular interaction in each case is an N—H...O hydrogen bond, which generates either chains or inversion dimers. Weak C—H...O, C—H...π and π–π interactions occur in these structures but there is no consistent pattern amongst them. Two of these compounds act as modest enhancers of CB1 cannabanoid signalling and two are inactive.

scholarly journals Crystal Packing and Supramolecular Motifs in Four Phenoxyalkanoic Acid Herbicides—Low-Temperature Redeterminations

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Lesław Sieroń ◽  
Joanna Kobyłecka ◽  
Anna Turek
Keyword(s):  
Low Temperature ◽  
Propionic Acid ◽  
Crystal Packing ◽  
Dichlorophenoxyacetic Acid ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography ◽  
Supramolecular Motifs ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Acid Herbicides

A low-temperature redetermination by X-ray crystallography of four phenoxyalkanoic acid herbicides, 4-chloro-2-methylphenoxyacetic acid (MCPA), rac-2-(4-chloro-2-methylphenoxy)propionic acid (MCPP), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4-dichlorophenoxybutyric acid (2,4-DB), allowed the supramolecular structures of these compounds to be precisely described in terms of C⋯O/C–H⋯π interactions. The geometric parameters of the redetermined structures agree with those previously reported, but with improved precision.

scholarly journals Different N—H...π interactions in two indole derivatives

2016 ◽  
Vol 72 (5) ◽  
pp. 699-703 ◽  
Author(s):  
Jamie R. Kerr ◽  
Laurent Trembleau ◽  
John M. D. Storey ◽  
James L. Wardell ◽  
William T. A. Harrison
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Intermolecular Interaction ◽  
Aromatic Ring ◽  
Stacking Interactions ◽  
Indole Derivatives ◽  
Asymmetric Unit ◽  
Π Interactions ◽  
Π Stacking

We describe the syntheses and crystal structures of two indole derivatives, namely 6-isopropyl-3-(2-nitro-1-phenylethyl)-1H-indole, C19H20N2O2, (I), and 2-(4-methoxyphenyl)-3-(2-nitro-1-phenylethyl)-1H-indole, C23H20N2O3, (II); the latter crystallizes with two molecules (AandB) with similar conformations (r.m.s. overlay fit = 0.139 Å) in the asymmetric unit. Despite the presence of O atoms as potential acceptors for classical hydrogen bonds, the dominant intermolecular interaction in each crystal is an N—H...π bond, which generates chains in (I) andA+AandB+Binversion dimers in (II). A different aromatic ring acts as the acceptor in each case. The packing is consolidated by C—H...π interactions in each case but aromatic π–π stacking interactions are absent.

Crystal structure relations in the binary system Li–Sn including the compound c-Li3Sb

2020 ◽  
Vol 235 (12) ◽  
pp. 581-590
Author(s):  
Patric Berger ◽  
Clemens Schmetterer ◽  
Herta Silvia Effenberger ◽  
Hans Flandorfer
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Topological Analysis ◽  
Building Blocks ◽  
Three Dimensions ◽  
Structural Elements ◽  
Compound C ◽  
Similarities And Differences ◽  
The Individual ◽  
Hierarchical Scheme

AbstractA topological analysis of the crystal structures of Li, Li–Sn compounds, Li8Sn3−xSbx and metastable c-Li3Sb showed that these structures can be described by a hierarchical scheme of building blocks based on atom blocks and polyhedra blocks, respectively. These blocks are linked in distinct ways to form the individual 3D atom arrangement. A common model was established for the construction of the mentioned structures from bespoke building blocks, for which bcc-Li is the aristotype. This latter structure can be described on the basis of hexa-capped cubes from which variants are derived through substitution of Li by Sn (or Sb). These are then combined into polyhedra blocks that are in turn assembled into polyhedra sequences. These latter are repeated and linked in three dimensions to form the whole crystal structure. At xSn ≥ 0.5, this mechanism changes and structural elements from bcc-Li and β-Sn can be observed in LiSn and Li2Sn5. In this work, we present the similarities and differences between the various crystal structures, the topological model with its construction rules and its limitations.

scholarly journals Crystal structures of 2-(2-bromo-5-fluorophenyl)-8-ethoxy-3-nitro-2H-thiochromene and 2-(2-bromo-5-fluorophenyl)-7-methoxy-3-nitro-2H-thiochromene

2019 ◽  
Vol 75 (11) ◽  
pp. 1783-1786
Author(s):  
Chien Thang Pham ◽  
Dinh Hung Mac ◽  
Thai Thanh Thu Bui
Keyword(s):  
Crystal Structures ◽  
Phenyl Ring ◽  
Crystal Packing ◽  
Condensation Reaction ◽  
Π Interactions ◽  
Π Stacking

Two thiochromene compounds containing Br and F atoms, namely 2-(2-bromo-5-fluorophenyl)-8-ethoxy-3-nitro-2H-thiochromene (C17H13BrFNO3S, A) and 2-(2-bromo-5-fluorophenyl)-7-methoxy-3-nitro-2H-thiochromene (C16H11BrFNO3S, B), were prepared via the condensation reaction between 2-mercaptobenzaldehyde and nitrostyrene derivatives. In both compounds, the thiochromene plane is almost perpendicular to the phenyl ring. In the structure of A, molecules are assembled via π–π stacking and C—H...O and C—F...π interactions. In the crystal packing of B, molecules are linked by C—H...F, C—H...O, C—H...π and π–π interactions.

scholarly journals The Isocyanide Complexes cis-[MCl2(CNC6H4-4-X)2] (M = Pd, Pt; X = Cl, Br) as Tectons in Crystal Engineering Involving Halogen Bonds

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 799
Author(s):  
Maria V. Kashina ◽  
Daniil M. Ivanov ◽  
Mikhail A. Kinzhalov
Keyword(s):  
Dft Calculations ◽  
Crystal Engineering ◽  
Crystal Packing ◽  
Noncovalent Interactions ◽  
Topological Analysis ◽  
Electron Localization ◽  
Halogen Bonds ◽  
Isocyanide Ligands ◽  
1D Chains

The isocyanide complexes cis-[MCl2(CNC6H4-4-X)2] (M = Pd; X = Cl, Br; M = Pt; X = Br) form isomorphous crystal structures exhibiting the Cl/Br and Pd/Pt exchanges featuring 1D chains upon crystallisation. Crystal packing is supported by the C–X···X–C halogen bonds (HaBs), C–H···X–C hydrogen bonds (HB), X···M semicoordination, and C···C contacts between the C atoms of aryl isocyanide ligands. The results of DFT calculations and topological analysis indicate that all the above contact types belong to attractive noncovalent interactions. A projection of the electron localization function (ELF) and an inspection of the electron density (ED) and the electrostatic potential (ESP) reveal the amphiphilic nature of X atoms playing the role of HaB donors, HaB and HB acceptors, and a nucleophilic partner in X···M semicoordination.

Design and Crystal Structures of Triple Helicates with Crystallographic IdealizedD3Symmetry:  The Role of Side Chain Effect on Crystal Packing

2002 ◽  
Vol 41 (23) ◽  
pp. 5978-5985 ◽  
Author(s):  
Guo Dong ◽  
Pang Ke-liang ◽  
Duan Chun-ying ◽  
He Cheng ◽  
Meng Qing-jin
Keyword(s):  
Crystal Structures ◽  
Crystal Packing ◽  
Side Chain
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