Supramolecular synthons based on N–H⋯N and C–H⋯O hydrogen bonds. Crystal engineering of a helical structure with 5,5-diethylbarbituric acid

2002 ◽  
pp. 1830-1831 ◽  
Author(s):  
Peddy Vishweshwar ◽  
Ram Thaimattam ◽  
Mariusz Jaskólski ◽  
Gautam R. Desiraju
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Helical Structure ◽  
Supramolecular Synthons ◽  
Diethylbarbituric Acid

scholarly journals Two-dimensional crystal engineering using halogen and hydrogen bonds: towards structural landscapes

2017 ◽  
Vol 8 (5) ◽  
pp. 3759-3769 ◽  
Author(s):  
Arijit Mukherjee ◽  
Joan Teyssandier ◽  
Gunther Hennrich ◽  
Steven De Feyter ◽  
Kunal S. Mali
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Two Dimensional ◽  
Supramolecular Synthons ◽  
Solid Interface ◽  
Dimensional Crystal

We apply the concepts of supramolecular synthons and structural landscapes to 2D crystallization at the solution–solid interface.

scholarly journals Charge density studies on 1:1 co-crystals of ethenzamide and saccharin

2014 ◽  
Vol 70 (a1) ◽  
pp. C964-C964
Author(s):  
Lucy Mapp ◽  
Mateusz Pitak ◽  
Simon Coles ◽  
Srinivasulu Aitipamula
Keyword(s):  
Hydrogen Bonds ◽  
Charge Density ◽  
Crystal Engineering ◽  
Chemical Properties ◽  
Secondary Level ◽  
Crystal Form ◽  
Monoclinic Space Group ◽  
Stoichiometric Ratio ◽  
Distribution Analysis ◽  
Space Group

The study of multi-component crystals, as well as the phenomenon of polymorphism, both have relevance to crystal engineering. Obtaining a specific polymorph is crucial as different polymorphs usually exhibit different physical and chemical properties and often the origin of this behaviour is unknown. This is especially important in the pharmaceutical industry. Herein, we present results of comparative studies of an analgesic drug, ethenzamide and its co-crystals with saccharin. The co-crystalisation of ethenzamide (2-ethoxybenzamide, EA) with saccharin (1,1-dioxo-,1,2-benzothiazol-3-one, SAC) with a 1:1 stoichiometric ratio resulted in two polymorphic forms of the co-crystal. Form I crystallises in the triclinic P-1 space group, whereas form II crystallises in monoclinic space group P21/n. Previous crystal structure analyses on forms I and II revealed that in both polymorphs the primary carboxy-amide-imide heterosynthon is the same, however the secondary level of interactions which extends the hydrogen bond network is different. Form I consists of extended linear tapes via N-H···O hydrogen bonds, whereas form II is composed of stacks of tetrameric motifs including N-H···O hydrogen bonds and C-H···O interactions. These two forms of EA-SAC can be classified as synthon polymorphs at a secondary level of hydrogen bonding [1]. In our approach an accurate, high resolution charge density distribution analysis has been carried out to obtain greater insight into the electronic structures of both types of the EA-SAC co-crystals and relate differences in electronic distribution with their polymorphic behaviour. To describe the nature and role of inter and intra-molecular interactions in a quantitative manner, the Hansen-Coppens formalism [2] and Bader's AIM theory [3] approach have been applied.

Halogen Bonds in Crystal Engineering: Like Hydrogen Bonds yet Different

2014 ◽  
Vol 47 (8) ◽  
pp. 2514-2524 ◽  
Author(s):  
Arijit Mukherjee ◽  
Srinu Tothadi ◽  
Gautam R. Desiraju
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Halogen Bonds

scholarly journals Side chain to main chain hydrogen bonds stabilize a polyglutamine helix in the activation domain of a transcription factor

2018 ◽  
Author(s):  
Albert Escobedo ◽  
Busra Topal ◽  
Micha Ben Achim Kunze ◽  
Juan Aranda ◽  
Giulio Chiesa ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Hydrogen Bonds ◽  
Transcriptional Activity ◽  
Main Chain ◽  
Muscular Atrophy ◽  
Helical Structure ◽  
Structural Basis ◽  
Tract Length ◽  
Spinobulbar Muscular Atrophy ◽  
Polyq Tract

Polyglutamine (polyQ) tracts are regions of low sequence complexity of variable length found in more than one hundred human proteins. These tracts are frequent in activation domains of transcription factors and their length often correlates with transcriptional activity. In addition, in nine proteins, tract elongation beyond specific thresholds causes polyQ disorders. To study the structural basis of the association between tract length, transcriptional activity and disease, here we addressed how the conformation of the polyQ tract of the androgen receptor (AR), a transcription factor associated with the polyQ disease spinobulbar muscular atrophy (SBMA), depends on its length. We found that the tract folds into a helical structure stabilized by unconventional hydrogen bonds between glutamine side chains and main chain carbonyl groups. These bonds are bifurcate with the conventional main chain to main chain hydrogen bonds stabilizing α-helices. In addition, since tract elongation provides additional interactions, the helicity of the polyQ tract directly correlates with its length. These findings suggest a plausible rationale for the association between polyQ tract length and AR transcriptional activity and have implications for establishing the mechanistic basis of SBMA.

Hierarchy of Supramolecular Synthons:  Persistent Hydroxyl···Pyridine Hydrogen Bonds in Cocrystals That Contain a Cyano Acceptor

2007 ◽  
Vol 4 (3) ◽  
pp. 401-416 ◽  
Author(s):  
Joanna A. Bis ◽  
Peddy Vishweshwar ◽  
David Weyna ◽  
Michael J. Zaworotko
Keyword(s):  
Hydrogen Bonds ◽  
Supramolecular Synthons

Reaction-path calculations and crystal structures of 1,1′-(ethylene-1,2-diyl)dipyridinium dichloride dihydrate and 1,1′-(ethylene-1,2-diyl)dipyridinium dibromide

2016 ◽  
Vol 72 (2) ◽  
pp. 112-118
Author(s):  
Mwaffak Rukiah ◽  
Mahmoud M. Al-Ktaifani ◽  
Mohammad K. Sabra
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Materials Science ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Substitution Reactions ◽  
Nucleophilic Substitutions ◽  
Triclinic Space Group ◽  
Pyridinium Bromide ◽  
Multinuclear Nmr Spectroscopy

The design of new organic–inorganic hybrid ionic materials is of interest for various applications, particularly in the areas of crystal engineering, supramolecular chemistry and materials science. The monohalogenated intermediates 1-(2-chloroethyl)pyridinium chloride, C5H5NCH2CH2Cl+·Cl−, (I′), and 1-(2-bromoethyl)pyridinium bromide, C5H5NCH2CH2Br+·Br−, (II′), and the ionic disubstituted products 1,1′-(ethylene-1,2-diyl)dipyridinium dichloride dihydrate, C12H14N22+·2Cl−·2H2O, (I), and 1,1′-(ethylene-1,2-diyl)dipyridinium dibromide, C12H14N22+·2Br−, (II), have been isolated as powders from the reactions of pyridine with the appropriate 1,2-dihaloethanes. The monohalogenated intermediates (I′) and (II′) were characterized by multinuclear NMR spectroscopy, while (I) and (II) were structurally characterized using powder X-ray diffraction. Both (I) and (II) crystallize with half the empirical formula in the asymmetric unit in the triclinic space groupP\overline{1}. The organic 1,1′-(ethylene-1,2-diyl)dipyridinium dications, which display approximateC2hsymmetry in both structures, are situated on inversion centres. The components in (I) are linkedviaintermolecular O—H...Cl, C—H...Cl and C—H...O hydrogen bonds into a three-dimensional framework, while for (II), they are connectedviaweak intermolecular C—H...Br hydrogen bonds into one-dimensional chains in the [110] direction. The nucleophilic substitution reactions of 1,2-dichloroethane and 1,2-dibromoethane with pyridine have been investigated byab initioquantum chemical calculations using the 6–31G** basis. In both cases, the reactions occur in two exothermic stages involving consecutive SN2 nucleophilic substitutions. The isolation of the monosubstituted intermediate in each case is strong evidence that the second step is not fast relative to the first.

The Dark Side of Crystal Engineering:  Creating Glasses from Small Symmetric Molecules that Form Multiple Hydrogen Bonds

2006 ◽  
Vol 128 (32) ◽  
pp. 10372-10373 ◽  
Author(s):  
Olivier Lebel ◽  
Thierry Maris ◽  
Marie-Ève Perron ◽  
Eric Demers ◽  
James D. Wuest
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Dark Side ◽  
Multiple Hydrogen Bonds
Sign in / Sign up

Export Citation Format

Share Document