Atomic and bond topological properties of the tripeptide l-alanyl–l-alanyl–l-alanine based on its experimental charge density obtained at 20 K

2006 ◽  
Vol 4 (3) ◽  
pp. 475 ◽  
Author(s):  
E. Rödel ◽  
M. Messerschmidt ◽  
B. Dittrich ◽  
P. Luger
Keyword(s):  
Charge Density ◽  
Topological Properties ◽  
Experimental Charge Density

scholarly journals Experimental charge density study and topological properties of Fidarestat

2007 ◽  
Vol 63 (a1) ◽  
pp. s28-s28
Author(s):  
El-E. Bendeif ◽  
C. Jelsch ◽  
B. Guillot ◽  
C. Lecomte ◽  
W. Morgenroth
Keyword(s):  
Charge Density ◽  
Topological Properties ◽  
Density Study ◽  
Experimental Charge Density

Experimental charge density in the transition metal complex Mn2(CO)10: a comparative study

2003 ◽  
Vol 59 (2) ◽  
pp. 234-247 ◽  
Author(s):  
Louis J. Farrugia ◽  
Paul R. Mallinson ◽  
Brian Stewart
Keyword(s):  
Charge Density ◽  
Transition Metal Complex ◽  
Topological Analysis ◽  
Atoms In Molecules ◽  
Topological Properties ◽  
B3lyp Level ◽  
Metal Metal ◽  
Density Study ◽  
Experimental Charge Density ◽  
Metal Ligand

An accurate experimental charge density study at 100 K of Mn2(CO)10 [bis(pentacarbonylmanganese)(Mn—Mn)] has been undertaken. A comparison with previously reported structural determinations reveals no evidence for significant Mn—Mn bond lengthening between 100 and 296 K. The nature of the metal–metal and metal–ligand atom interactions has been studied by topological analysis using the Atoms in Molecules (AIM) approach of Bader [(1990), Atoms in Molecules: a Quantum Theory.Oxford: Clarendon Press]. An analysis of the density ρ(r), the Laplacian of the density ∇2ρ(r b ) and the total energy densities H(r b ) at the bond critical points is used to classify all the chemical bonds as covalent in nature. The results are compared qualitatively and quantitatively with previous charge density studies on this molecule and DFT calculations at the 6-311+G* B3LYP level. The topological properties of the theoretical and experimental densities are in close agreement.

scholarly journals Experimental charge-density study on the nickel(II) coordination complex [Ni(H3 L)][NO3][PF6] [H3 L = N,N′,N′′-tris(2-hydroxy-3-methylbutyl)-1,4,7-triazacyclononane]: a reappraisal

2006 ◽  
Vol 62 (2) ◽  
pp. 236-244 ◽  
Author(s):  
L. J. Farrugia ◽  
C. S. Frampton ◽  
J. A. K. Howard ◽  
P. R. Mallinson ◽  
R. D. Peacock ◽  
...  
Keyword(s):  
Charge Density ◽  
Density Functional ◽  
Macrocyclic Ligand ◽  
Original Data ◽  
Title Complex ◽  
Topological Properties ◽  
Bond Path ◽  
Laplacian Distribution ◽  
Experimental Charge Density ◽  
Programming Errors

The experimental charge density in the title complex has been re-examined. The original work, reported some 8 years ago [Smith et al. (1997). J. Am. Chem. Soc. 119, 5028–5034], was undertaken using a very early version of the XD software, which contained serious programming errors. A re-refinement, using the original data and a recent version of the XD software, shows that many of the unusual aspects of this earlier study are artefacts due to these programming errors. The topological properties of the newly obtained experimental density compare well with those calculated from a theoretical DFT (density-functional theory) UHF-SCF (unrestricted Hartree Fock–self-consistent field) density. This report corrects several erroneous conclusions regarding the charge density in the title complex – in particular, the highly unusual diffuse Laplacian distribution about the Ni atom, and the trifurcated bond path from the Ni atom to the alcohol oxygen donor atoms are no longer observed. An examination of a range of topological properties of the metal–ligand bonds leads to the conclusion that the Ni—N and Ni—O bonds have an intermediate character, with a significant shared interaction, but with a substantial ionic component. This new study also reveals a previously unrecognized intramolecular H...H interaction in the macrocyclic ligand.

scholarly journals Charge density research: from inorganic and molecular materials to proteins

2005 ◽  
Vol 220 (4) ◽  
Author(s):  
Claude Lecomte ◽  
Emmanuel Aubert ◽  
Vincent Legrand ◽  
Florence Porcher ◽  
Sébastien Pillet ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Coordination Chemistry ◽  
Charge Density ◽  
Material Science ◽  
Electrostatic Energy ◽  
Topological Properties ◽  
Liesst Effect ◽  
Derived Properties ◽  
Density Methods ◽  
Experimental Charge Density

AbstractThis paper intends to present applications of experimental charge density research in physics, chemistry and biology. It describes briefly most methods for modelling the charge density and calculating and analyzing derived properties (electrostatic potential, topological properties). These methods are illustrated through examples ranging from material science and coordination chemistry to biocrystallography, like the estimation of electrostatic energy in a zeolite-like material or the relation between electrostatic energy and spin density to macroscopic magnetic properties in a ferrimagnetic molecular material. The accurate structure and charge density of a coordination compound exhibiting LIESST effect is also described, together with an exemple of transferability of charge density methods to macromolecular science and protein crystallography.

Reproducability and transferability of topological properties; experimental charge density of the hexapeptide cyclo-(D,L-Pro)_2–(L-Ala)_4 monohydrate

2002 ◽  
Vol 58 (4) ◽  
pp. 721-727 ◽  
Author(s):  
B. Dittrich ◽  
T. Koritsánszky ◽  
M. Grosche ◽  
W. Scherer ◽  
R. Flaig ◽  
...  
Keyword(s):  
Amino Acids ◽  
High Resolution ◽  
Synchrotron Radiation ◽  
Charge Density ◽  
Topological Properties ◽  
Peptide Bonds ◽  
Area Detector ◽  
Experimental Density ◽  
Experimental Charge Density ◽  
Good Agreement

The charge density of a hexapeptide was determined from high-resolution CCD area-detector experiments at 100 K. Two datasets, one from a rotating anode and a second one from synchrotron radiation, were measured and the results are compared. The data are interpreted in terms of the `rigid pseudoatom' model. The topology of the experimental density is analyzed and compared with the topology of the constituting amino acids, and shows good agreement. All critical points of the electron density at the covalent and hydrogen bonds, as well as those of the Laplacian, were located. With respect to the transferability of electronic and bond topological properties the six peptide bonds were compared with values given in the literature.

Experimental charge density of an L-phenylalanine formic acid complex with a short hydrogen bond determined at 25 K

2006 ◽  
Vol 221 (9) ◽  
Author(s):  
Stefan Mebs ◽  
Marc Messerschmidt ◽  
Peter Luger
Keyword(s):  
Hydrogen Bond ◽  
High Resolution ◽  
Formic Acid ◽  
Charge Density ◽  
Topological Properties ◽  
Acid Complex ◽  
Data Set ◽  
X Ray ◽  
Short Hydrogen Bond ◽  
Experimental Charge Density

AbstractThe experimental charge density and related atomic and bond topological properties of an L-phenylalanine formic acid complex were derived from a high resolution X-ray data set (sin θ/λ = 1.18 Å

Revisiting the charge density analysis of 2,5-dichloro-1,4-benzoquinone at 20 K

2017 ◽  
Vol 73 (4) ◽  
pp. 654-659 ◽  
Author(s):  
Zhijie Chua ◽  
Bartosz Zarychta ◽  
Christopher G. Gianopoulos ◽  
Vladimir V. Zhurov ◽  
A. Alan Pinkerton
Keyword(s):  
Charge Density ◽  
Electron Density ◽  
Topological Analysis ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Total Electron Density ◽  
Total Electron ◽  
Structure Factors ◽  
Density Analysis ◽  
Experimental Charge Density

A high-resolution X-ray diffraction measurement of 2,5-dichloro-1,4-benzoquinone (DCBQ) at 20 K was carried out. The experimental charge density was modeled using the Hansen–Coppens multipolar expansion and the topology of the electron density was analyzed in terms of the quantum theory of atoms in molecules (QTAIM). Two different multipole models, predominantly differentiated by the treatment of the chlorine atom, were obtained. The experimental results have been compared to theoretical results in the form of a multipolar refinement against theoretical structure factors and through direct topological analysis of the electron density obtained from the optimized periodic wavefunction. The similarity of the properties of the total electron density in all cases demonstrates the robustness of the Hansen–Coppens formalism. All intra- and intermolecular interactions have been characterized.

Characterization of the B⋯π-system interaction via topology of the experimental charge density distribution in the crystal of 3-chloro-7α-phenyl-3-borabicyclo[3.3.1]nonane

2004 ◽  
Vol 384 (1-3) ◽  
pp. 40-44 ◽  
Author(s):  
Konstatin A Lyssenko ◽  
Mikhail Yu Antipin ◽  
Mikhail E Gurskii ◽  
Yurii N Bubnov ◽  
Anna L Karionova ◽  
...  
Keyword(s):  
Density Distribution ◽  
Charge Density ◽  
Charge Density Distribution ◽  
Experimental Charge Density
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