Electron Density of Paracetamol Metastable Polymorph, Topologycal H-Bonds Analysis

2013 ◽  
Vol 8 (2) ◽  
pp. 109-116
Author(s):  
Dmitriy Druzhbin ◽  
Tatyana Drebushchak ◽  
Elena Boldyreva
Keyword(s):  
Electron Density ◽  
Critical Points ◽  
Experimental Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Orthorhombic Modification ◽  
Experimental Electron Density

The experimental electron density of paracetamol metastable polymorph (orthorhombic, Pbca) was derived from highresolution X-ray diffraction at 100 K. The multipole model was used to refine electron density and for experimental analysis of the features of the critical points for orthorhombic modification. Geometrical H-bonds features were obtained from spherical and multipole models. The current study provides topological H-bonds analysis in orthorhombic paracetamol compared with stable monoclinic paracetamol polymorphs in normal conditions

Distribution and Topology of the Electron Density in an Aluminosilicate Compound from High-Resolution X-ray Diffraction Data: the Case of Scolecite

1998 ◽  
Vol 54 (6) ◽  
pp. 819-833 ◽  
Author(s):  
S. Kuntzinger ◽  
N. E. Ghermani ◽  
Y. Dusausoy ◽  
C. Lecomte
Keyword(s):  
High Resolution ◽  
Density Distribution ◽  
Electron Density ◽  
Critical Points ◽  
Diffraction Data ◽  
Electron Density Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
And Topology ◽  
Experimental Electron Density

The experimental electron density distribution in scolecite, CaAl2Si3O10.3H2O, has been derived from single-crystal high-resolution Ag Kα X-ray diffraction data. A statistical method based on the prediction matrix has been used to discuss the estimation of the valence populations (P val) in the kappa least-squares refinements. The densities on the Si—O—Si and Si—O—Al bridges have been characterized using the topology of the electron density through its Laplacian at the bond critical points. The Si—O and Al—O bond features are related to the atomic environment and to the Si—O—T geometries (T = Si, Al).

Weak interactions in chain polymers [M(μ-X)2 L 2]∞ (M = Zn, Cd; X = Cl, Br; L = substituted pyridine) – an electron density study

2009 ◽  
Vol 65 (5) ◽  
pp. 600-611 ◽  
Author(s):  
Ruimin Wang ◽  
Christian W. Lehmann ◽  
Ulli Englert
Keyword(s):  
Hydrogen Bonds ◽  
Electron Density ◽  
Critical Points ◽  
Weak Interactions ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Density Distributions ◽  
The One ◽  
Experimental Electron Density ◽  
Density Study

The experimental electron-density distributions in crystals of five chain polymers [M(μ-X)2(py)2] (M = Zn, Cd; X = Cl, Br; py = 3,5-substituted pyridine) have been obtained from high-resolution X-ray diffraction data sets (sin θ/λ > 1.1 Å−1) at 100 K. Topological analyses following Bader's `Atoms in Molecules' approach not only confirmed the existence of (3, −1) critical points for the chemically reasonable and presumably strong covalent and coordinative bonds, but also for four different secondary interactions which are expected to play a role in stabilizing the polymeric structures which are unusual for Zn as the metal center. These weaker contacts comprise intra- and inter-strand C—H...X—M hydrogen bonds on the one hand and C—X...X—C interhalogen contacts on the other hand. According to the experimental electron-density studies, the non-classical hydrogen bonds are associated with higher electron density in the (3, −1) critical points than the halogen bonds and hence are the dominant interactions both with respect to intra- and inter-chain contacts.

Experimental charge density and electrostatic potential of glycyl-L-threonine dihydrate

2000 ◽  
Vol 56 (1) ◽  
pp. 155-165 ◽  
Author(s):  
Farid Benabicha ◽  
Virginie Pichon-Pesme ◽  
Christian Jelsch ◽  
Claude Lecomte ◽  
Ahmed Khmou
Keyword(s):  
Electron Density ◽  
Electrostatic Potential ◽  
Electron Density Distribution ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Topological Methods ◽  
X Ray ◽  
Molecular Electron ◽  
Experimental Electron Density ◽  
Experimental Charge Density

The experimental electron density distribution in glycyl-L-threonine dihydrate has been investigated using single-crystal X-ray diffraction data at 110 K to a resolution of (sin θ/λ) = 1.2 Å−1. Multipolar pseudo-atom refinement was carried out against 5417 observed data and the molecular electron density was analyzed using topological methods. The experimental electrostatic potential around the molecule is discussed in terms of molecular interactions. Crystal data: C6H12N2O4.2H2O, Mr = 212.2, orthorhombic, P212121, Z = 4, F(000) = 456 e, T = 110 K, a = 9.572 (3), b = 10.039 (3), c = 10.548 (2) Å, V = 1013.6 (4) Å3, Dx = 1.3 g cm−3, µ = 1.2 cm−1 for λMo = 0.7107 Å.

Experimental electron density study of 1,2,4-triazole at 15 K. A comparison with ab initio-calculations

1997 ◽  
Vol 212 (3) ◽  
Author(s):  
P. Fuhrmann ◽  
T. Koritsánszky ◽  
P. Luger
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electron Density ◽  
Diffraction Data ◽  
Topological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Electron Density ◽  
Density Study

AbstractTopological properties and the Laplacian function of the electron density of 1,2,4-triazole have been determined from X-ray diffraction data collected at 15 K. 1,2,4-Triazole, C

Submolecular partitioning of morphine hydrate based on its experimental charge density at 25 K

2005 ◽  
Vol 61 (4) ◽  
pp. 443-448 ◽  
Author(s):  
S. Scheins ◽  
M. Messerschmidt ◽  
P. Luger
Keyword(s):  
Electron Density ◽  
Electron Density Distribution ◽  
Theoretical Calculations ◽  
Topological Analysis ◽  
Theoretical Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resolution Single ◽  
Experimental Electron Density ◽  
Experimental Charge Density

The electron density distribution of morphine hydrate has been determined from high-resolution single-crystal X-ray diffraction measurements at 25 K. A topological analysis was applied and, in order to analyze the submolecular transferability based on an experimental electron density, a partitioning of the molecule into atomic regions was carried out, making use of Bader's zero-flux surfaces to yield atomic volumes and charges. The properties obtained were compared with the theoretical calculations of smaller fragment molecules, from which the complete morphine molecule can be reconstructed, and with theoretical studies of another opiate, Oripavine PEO, reported in the literature.

scholarly journals Is It Conjugated or Not? The Theoretical and Experimental Electron Density Map of Bonding in p-CH3CH2COC6H4-C≡C-C≡C-p-C6H4COCH3CH2

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4388 ◽  
Author(s):  
Przemysław Starynowicz ◽  
Sławomir Berski ◽  
Nurbey Gulia ◽  
Karolina Osowska ◽  
Tadeusz Lis ◽  
...  
Keyword(s):  
Electron Density ◽  
Theoretical Calculations ◽  
Topological Analysis ◽  
Carbon Chain ◽  
Small Contribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Map ◽  
Electron Density Map ◽  
Experimental Electron Density

The electron density of p-CH3CH2COC6H4-C≡CC≡C-p-C6H4COCH3CH2 has been investigated on the basis of single-crystal X-ray diffraction data collected to high resolution at 100 K and from theoretical calculations. An analysis of the X-ray data of the diyne showed interesting “liquidity” of electron distribution along the carbon chain compared to 1,2-diphenylacetylene. These findings are compatible with the results of topological analysis of Electron Localization Function (ELF), which has also revealed a larger (than expected) concentration of the electron density at the single bonds. Both methods indicate a clear π-type or “banana” character of a single bond and a significant distortion from the typical conjugated structure of the bonding in the diyne with a small contribution of cumulenic structures.

Charge density in crystalline citrinin from X-ray diffraction at 19 K

1996 ◽  
Vol 74 (6) ◽  
pp. 1145-1161 ◽  
Author(s):  
Pietro Roversi ◽  
Felicita Merati ◽  
Riccardo Destro ◽  
Mario Barzaghi
Keyword(s):  
Electron Density ◽  
Chemical Reactivity ◽  
Topological Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Path ◽  
Topological Features ◽  
Path Lengths ◽  
The Stability ◽  
Experimental Electron Density

For the fungal metabolite citrinin, C13H14O5, the total experimental electron distribution ρ(r) and its Laplacian [Formula: see text] have been obtained from an extensive set (36 564 measurements) of single-crystal X-ray diffracted intensities at a temperature of 19 ± 2 K. Relevant steps in data collection and processing are reported. The resulting 7698 independent intensity data have been analysed with a multipole (pseudoatoms) formalism. The topological properties of ρ(r) have been determined according to the quantum theory of atoms in molecules. CC and CO bond path lengths have been obtained by numerical integration; their values are found to be well correlated with those of the electron density at the bond critical points. Topological features have been used to characterize the extension of the conjugated system of the molecule, and to confirm the stability of its rings, particularly the two formed by intramolecular H bonds. Maps of [Formula: see text] are presented, showing details in the valence charge distribution and providing a very sensitive tool for analysing dependence of the density on the model adopted to interpret X-ray data. The known chemical reactivity of the molecule towards nucleophiles at a Csp2 atom is confirmed by the shape of the molecular reactive surface (the zero envelope of [Formula: see text]). Key words: experimental electron density, low-temperature X-ray diffraction, topological analysis, Laplacian of ρ.

Experimental electron density study of the supramolecular aggregation between 4,4′-dipyridyl-N,N′-dioxide and 1,4-diiodotetrafluorobenzene at 90 K

2004 ◽  
Vol 60 (5) ◽  
pp. 559-568 ◽  
Author(s):  
Riccardo Bianchi ◽  
Alessandra Forni ◽  
Tullio Pilati
Keyword(s):  
Electron Density ◽  
Halogen Bond ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Experimental Electron Density ◽  
Supramolecular Aggregation ◽  
Density Study

The electron density of the halogen-bonded complex of 4,4′-dipyridyl-N,N′-dioxide (bpNO) with 1,4-diiodotetrafluorobenzene (F4dIb) at 90 K has been determined by X-ray diffraction and analysed. The nature of the I...O intermolecular bond connecting the bpNO and F4dIb molecules into one-dimensional infinite chains, as well as the other non-covalent interactions present in the crystal, such as C—H...O, C—H...F and C—H...I hydrogen bonds and C...C, C...N, C...I and F...F interactions, have been investigated. The integration of electron density over the atomic basins reveals the electrostatic nature of the I...O halogen bond, which is very similar to a previously analysed I...N halogen bond.

Experimental electron density in the triclinic phase of Co2(CO)6(μ-CO)(μ-C4O2H2) at 120 K

2001 ◽  
Vol 57 (5) ◽  
pp. 638-645 ◽  
Author(s):  
Riccardo Bianchi ◽  
Giuliana Gervasio ◽  
Domenica Marabello
Keyword(s):  
Bond Length ◽  
Electron Density ◽  
Closed Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Path ◽  
Length Difference ◽  
Triclinic Phase ◽  
Two Phases ◽  
Experimental Electron Density

The experimental electron density (ED) of the triclinic phase of Co2(CO)6(μ-CO)(μ-C4O2H2), μ-carbonyl-μ-5-oxo-2,5-dihydrofuran-2-ylbis(tricarbonylcobalt), has been determined through X-ray diffraction at 120 K. The presence of a `closed shell' Co—Co bond in the title compound, found in an experimental ED study of its orthorhombic form, is confirmed by the Quantum Theory of Atoms in Molecules. However, the two phases show a significant Co—Co bond length difference [triclinic: 2.4402 (2) Å; orthorhombic: 2.4222 (3) Å]. The flat distribution of the experimental ED along the Co—Co bond path and on the two Co2C rings allows for variations of the Co—Co bond length which may be easily induced by the different packing arrangements of the two forms.

Analyzing experimental electron density with the localized-orbital locator

2002 ◽  
Vol 58 (5) ◽  
pp. 780-785 ◽  
Author(s):  
Vladimir Tsirelson ◽  
Adam Stash
Keyword(s):  
Solid State ◽  
Electron Density ◽  
Chemical Bonds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Second Derivatives ◽  
Atomic Interactions ◽  
Different Types ◽  
Localized Orbital ◽  
Experimental Electron Density

The localized-orbital locator, which describes the features of bonding in terms of the local kinetic energy, is approximately expressed as a function of electron density and its first and second derivatives. Calculations based on accurate electron densities derived from X-ray diffraction data are carried out for crystals with different types of chemical bonds. It is demonstrated that the localized-orbital locator reveals the features of atomic interactions in a solid state and allows the covalent, ionic and van der Waals bonds to be distinguished.

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