scholarly journals A variable-temperature X-ray diffraction and theoretical study of conformational polymorphism in a complex organic molecule (DTC)

RSC Advances ◽  
2018 ◽  
Vol 8 (67) ◽  
pp. 38445-38454 ◽  
Author(s):  
Andrea Gionda ◽  
Giovanni Macetti ◽  
Laura Loconte ◽  
Silvia Rizzato ◽  
Ahmed M. Orlando ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Crystal Packing ◽  
Variable Temperature ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complex Organic Molecule ◽  
Non Covalent Interactions ◽  
Complex Organic ◽  
Covalent Interactions

A small conformational change in the asymmetric unit has a significant effect on how non-covalent interactions determine (i) the crystal packing and (ii) the effect of T on the relative balance of electrostatics and dispersion–repulsions.

Experimental and theoretical study on the molecular structure, covalent and non-covalent interactions of 2,4-dinitrodiphenylamine: X-ray diffraction and QTAIM approach

2017 ◽  
Vol 1141 ◽  
pp. 53-63 ◽  
Author(s):  
Javier Hernández-Paredes ◽  
Roberto C. Carrillo-Torres ◽  
Ofelia Hernández-Negrete ◽  
Rogerio R. Sotelo-Mundo ◽  
Daniel Glossman-Mitnik ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Theoretical Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Influence of 3-{5-[4-(diethylamino)benzylidene]rhodanine}propionic acid on the conformation of 5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-4(5H)-one

2018 ◽  
Vol 74 (11) ◽  
pp. 1427-1433 ◽  
Author(s):  
Ewa Żesławska ◽  
Wojciech Nitek ◽  
Waldemar Tejchman ◽  
Jadwiga Handzlik
Keyword(s):  
Crystal Structures ◽  
Crystal Packing ◽  
Protonated Form ◽  
Acid Form ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Basic Form ◽  
Piperazine Ring ◽  
X Ray ◽  
Intermolecular Contacts

The arylidene–imidazolone derivatives are a group of compounds of great interest in medicinal chemistry due to their various pharmacological actions. In order to study the possible conformations of an arylidene–imidazolone derivative, two new crystal structures were determined by X-ray diffraction, namely (Z)-5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-5(4H)-one, C15H17ClN4O, (6), and its salt 4-[5-(4-chlorobenzylidene)-5-oxo-4,5-dihydro-3H-imidazol-2-yl]-1-methylpiperazin-1-ium 3-{5-[4-(diethylamino)benzylidene]-4-oxo-2-thioxothiazolidin-3-yl}propionate, C15H18ClN4O+·C17H19N2O3S2 −, (7). Both compounds crystallize in the space group P\overline{1}. The basic form (6) crystallizes with two molecules in the asymmetric unit. In the acid form of (6), the N atom of the piperazine ring is protonated by proton transfer from the carboxyl group of the rhodanine acid derivative. The greatest difference in the conformations of (6) and its protonated form, (6c), is observed in the location of the arylidene–imidazolone substituent at the N atom. In the case of (6c), the position of this substituent is close to axial, while for (6), the corresponding position is intermediate between equatorial and axial. The crystal packing is dominated by a network of N—H...O hydrogen bonds. Furthermore, the crystal structures are stabilized by numerous intermolecular contacts of types C—H...N and C—H...Cl in (6), and C—H...O and C—H...S in (7). The geometry with respect to the location of the substituents at the N atoms of the piperazine ring was compared with other crystal structures possessing an N-methylpiperazine moiety.

Dynamic constitutional hybrid materials-toward adaptive self-organized devices

2009 ◽  
Vol 1189 ◽  
Author(s):  
Mihail Barboiu ◽  
Adinela Cazacu ◽  
Simona Mihai ◽  
Yves-Marie Legrand ◽  
Arie van der Lee
Keyword(s):  
Hybrid Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrophobic Silica ◽  
Self Organized ◽  
Non Covalent Interactions ◽  
Covalent Interactions

AbstractDynamic constitutional hybrid materials in which the functional self-organized macrocycles are reversibly connected with the inorganic silica mesopores through hydrophobic non-covalent interactions. Supramolecular columnar self-organized architectures confined within scaffolding hydrophobic silica mesopores can be structurally determined by using X-ray diffraction techniques.

scholarly journals Decoding conformational polymorphism in organic substances

2014 ◽  
Vol 70 (a1) ◽  
pp. C557-C557
Author(s):  
Ahmed Orlando ◽  
Laura Loconte ◽  
Emanuele Ortoleva ◽  
Carlo Gatti ◽  
Leonardo Lo Presti
Keyword(s):  
Molecular Conformation ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
Self Recognition ◽  
Crystallization Conditions ◽  
Polymorphic Forms ◽  
Non Covalent Interactions ◽  
Cohesive Energies ◽  
Covalent Interactions

Different polymorphs have different intensive physical properties and it is still impossible to predict from scratch if a change in the crystallization conditions will result in different crystal structures or not. In this contribution, possible correlations are highlighted among charge density features, molecular conformation and interaction energetics in the two known polymorphic forms of (DTC)[1,2], an isothiazole β-sultamic derivative. A tentative rationale is provided for the relative stability of the two forms on the basis of their different self-recognition patterns. Both polymorphs crystallize in the same P21/n space group and show very different non-covalent networks of weak C-H–X (X = N,O,π) interactions due to the dissimilar conformation of the asymmetric units (ASU). Accurate multi-temperature (100 K ≤ T ≤ 298 K) single-crystal X-Ray diffraction experiments were carried out and the evolution of crystal packing and self-recognition energetics were monitored through periodic quantum-mechanical calculations at fixed geometries. Preliminary results show that dispersive/repulsive and electrostatic non-covalent interactions dominate the crystal packing in both polymorphs. At T=100 K the form A have a tighter packing, as it shows a greater propensity in being involved in H bonds than B (see the Hirshfeld surface fingerprint plots[3] of forms A -left- and B -right- here reported). This reflects in greater density, whereas the estimated DFT cohesive energies of the two forms are similar. DTC has enough molecular flexibility to access various favourable arrangements during the nucleation, as the interconversion between the A and B conformers in the gas phase takes place with a very small activation energy. The possible role of the solvent in favouring either of the two observed conformations is discussed.

scholarly journals The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts

2010 ◽  
Vol 6 ◽  
Author(s):  
Kari Raatikainen ◽  
Massimo Cametti ◽  
Kari Rissanen
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Halogen Bonding ◽  
Relative Strength ◽  
Supramolecular Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Database ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The series of haloanilinium and halopyridinium salts: 4-IPhNH3Cl (1), 4-IPhNH3Br (5), 4-IPhNH3H2PO4 (6), 4-ClPhNH3H2PO4 (8), 3-IPyBnCl (9), 3-IPyHCl (10) and 3-IPyH-5NIPA (3-iodopyridinium 5-nitroisophthalate, 13), where hydrogen or/and halogen bonding represents the most relevant non-covalent interactions, has been prepared and characterized by single crystal X-ray diffraction. This series was further complemented by extracting some relevant crystal structures: 4-BrPhNH3Cl (2, CCDC ref. code TAWRAL), 4-ClPhNH3Cl (3, CURGOL), 4-FPhNH3Cl (4, ANLCLA), 4-BrPhNH3H2PO4, (7, UGISEI), 3-BrPyHCl, (11, CIHBAX) and 3-ClPyHCl, (12, VOQMUJ) from Cambridge Structural Database for sake of comparison. Based on the X-ray data it was possible to highlight the balance between non-covalent forces acting in these systems, where the relative strength of the halogen bonding C–X···A− (X = I, Br or Cl) and the ratio between the halogen and hydrogen bonds [C–X···A− : D–H···A−] varied across the series.

Color-tunable phosphorescence of 1,10-phenanthrolines by 4,7-methyl/-diphenyl/-dichloro substituents in cocrystals assembledviabifurcated C—I...N halogen bonds using 1,4-diiodotetrafluorobenzene as a bonding donor

2017 ◽  
Vol 73 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Rui Liu ◽  
Yuan Jun Gao ◽  
Wei Jun Jin
Keyword(s):  
Noncovalent Interactions ◽  
Halogen Bonding ◽  
Luminescent Properties ◽  
Halogen Bonds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Color Tunable ◽  
Non Covalent Interactions ◽  
The Impact ◽  
Covalent Interactions

Single-crystal X-ray diffraction reveals a series of phosphorescent cocrystals which were assembled by 1,4-diiodotetrafluorobenzene (1,4-DITFB) and either 4,7-dimethyl-1,10-phenanthroline (DMPhe), 4,7-diphenyl-1,10-phenanthroline (DPPhe) or 4,7-dichloro-1,10-phenanthroline (DClPhe)viaC—I...N halogen bonding. These cocrystals, labeled (1), (2) and (3), respectively, are phosphorescent and a distinct change in phosphorescent color can be observed from orange–yellow, green to yellow–green, with well defined vibrational band maxima at 587, 520 and 611 nm for (1), (2) and (3). Based on the dependence of halogen bonding in sites and strength, we discussed the impact of substituents with different electron-withdrawing effects and steric hindrance on intermolecular noncovalent interactions and phosphorescence. The method of inducing and modulating phosphorescence by halogen bonding and other weak non-covalent interactions through changing the substituent groups of molecules should be significant in both theory and the application of optical function materials with predictable and modulated luminescent properties.

scholarly journals A Comparative Theoretical and Spectroscopic Study of Aminomethylbenzoic Acid Derivatives as Potential NLO Candidates

2020 ◽  
Vol 3 (1) ◽  
pp. 102
Author(s):  
Amani Direm ◽  
Koray Sayın
Keyword(s):  
Nmr Spectra ◽  
Close Agreement ◽  
Molecular Electrostatic Potential ◽  
Structural Parameters ◽  
13C Nmr Spectra ◽  
X Ray Diffraction ◽  
1H And 13C Nmr ◽  
X Ray ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Three aminomethylbenzoic acid derivatives were theoretically studied at M062X/6-311++G(d,p) level in a vacuum, namely 2-ammonio-5-methylcarboxybenzene perchlorate (1), 4-(ammoniomethyl) carboxybenzene nitrate (2) and 4-(ammoniomethyl)carboxybenze perchlorate (3). The compounds’ structures were fully optimized and compared with the single-crystal X-ray diffraction results, showing a very close agreement with the experimental structural parameters. Their IR, 1H- and 13C-NMR spectra were calculated and examined in detail. Furthermore, the molecular electrostatic potential (MEP) maps of the studied compounds were investigated and the strength of the non-covalent interactions evaluated. In addition to these results, the NLO properties of the three compounds were predicted.

scholarly journals Exploration of Weak Interactions in Penta-Substituted Cyclohexanol: Crystal Structure and DFT study

2021 ◽  
Vol 1 (1) ◽  
pp. 1-11
Author(s):  
Sudipta Pathak ◽  
◽  
Shibashis Halder ◽  
Malay Dolai ◽  
Saugata Konar ◽  
...  
Keyword(s):  
Crystal Packing ◽  
Weak Interactions ◽  
Geometry Optimization ◽  
Solvent Mixture ◽  
Dft Study ◽  
Supramolecular Framework ◽  
X Ray ◽  
Bonding Interaction ◽  
Non Covalent Interactions ◽  
Covalent Interactions

During attempts to produce penta-substituted cyclohexanol involving weak interactions, we have crystallized A [where, A = (1S,2S,3R,4S,6S)-2,6-bis(4-bromrophenyl)-4-hydroxy-4-(pyridin- 2-yl)cyclohexane-1,3-diyl)-bis(pyridin-2-ylmethanone)] in DMF-water (1 : 1) solvent mixture with the P-1 space group. Interestingly, in this class of compound, weak interactions have not been explored elaborately in the literature. Herein, we have investigated various types of weak interactions like π · · · π interaction, C–H · · · π interaction, Br· · · Br interaction and H-bonding interaction. These types of non-covalent interactions attribute to the supramolecular framework in the crystal packing of the studied molecule. In addition, the composition of the organic molecule A is confirmed from Single crystal X-ray structure and then performed the theoretical geometry optimization (DFT study) on it.

scholarly journals Synthesis and structure of (E)-N-(4-methoxyphenyl)-2-[4-(3-oxo-3-phenylprop-1-en-1-yl)phenoxy]acetamide

2021 ◽  
Vol 77 (2) ◽  
pp. 184-189
Author(s):  
Cong Nguyen Tien ◽  
Trung Vu Quoc ◽  
Dat Nguyen Dang ◽  
Giang Le Duc ◽  
Luc Van Meervelt
Keyword(s):  
Title Compound ◽  
Crystal Packing ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Hydrogen Bonding Interactions ◽  
Hirshfeld Analysis ◽  
Phenyl Rings ◽  
C Nmr

The title compound N-(4-methoxyphenyl)-2-[4-(3-oxo-3-phenylprop-1-en-1-yl)phenoxy]acetamide, C24H21NO4, was prepared from reaction of N-(4-methoxyphenyl)-2-chloroacetamide and (E)-3-(4-hydroxyphenyl)-1-phenylprop-2-en-1-one, which was obtained from the reaction of 4-hydroxybenzaldehyde and acetophenone. The structure of the title compound was determined by IR, 1H-NMR, 13C-NMR and HR–MS spectroscopic data and further characterized by single-crystal X-ray diffraction. The asymmetric unit contains four molecules, each displaying an E-configuration of the C=C bond. The dihedral angle between the phenyl rings in each molecule varies between 14.9 (2) and 45.8 (2)°. In the crystal, C—H...O hydrogen-bonding interactions link the molecules into chains running along the [001] direction. In addition, C—H...π interactions further stabilize the crystal packing. A Hirshfeld analysis indicates that the most important contributions to the surface contacts are from H...H (43.6%), C...H/H...C (32.1%) and O...H/H...O (18.1%) interactions.

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