scholarly journals Strong stacking interactions of metal–chelate rings are caused by substantial electrostatic component

2019 ◽  
Vol 48 (19) ◽  
pp. 6328-6332 ◽  
Author(s):  
Dušan P. Malenov ◽  
Snežana D. Zarić
Keyword(s):  
Metal Chelate ◽  
Electrostatic Energy ◽  
Stacking Interactions ◽  
Energy Component ◽  
Electrostatic Component ◽  
Chelate Rings

Stacking interactions of metal–chelate rings are strong due to very strong electrostatic energy component.

scholarly journals The Face-to-Face σ-Hole···σ-Hole Stacking Interactions: Structures, Energies, and Nature

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 877
Author(s):  
Yu Zhang ◽  
Weizhou Wang
Keyword(s):  
Quantum Chemical ◽  
Noncovalent Interactions ◽  
Electrostatic Energy ◽  
Stacking Interactions ◽  
Energy Component ◽  
Stacking Interaction ◽  
Face To Face ◽  
The Face ◽  
Π Stacking Interaction ◽  
Induction Energy

The existence of the π···π stacking interaction is well-known. Similarly, it is reasonable to assume the existence of the σ-hole···σ-hole stacking interaction. In this work, the structures, energies, and nature of the face-to-face σ-hole···σ-hole stacking interactions in the crystal structures have been investigated in detail by the quantum chemical calculations. The calculated results clearly show that the face-to-face σ-hole···σ-hole stacking interactions exist and have unique properties, although their strengths are not very significant. The energy component analysis reveals that, unlike many other dispersion-dominated noncovalent interactions in which the induction energies always play minor roles for their stabilities, for the face-to-face σ-hole···σ-hole stacking interaction the contribution of the induction energy to the total attractive energy is close to or even larger than that of the electrostatic energy. The structures, energies, and nature of the face-to-face σ-hole···σ-hole stacking interactions confined in small spaces have also been theoretically simulated. One of the important findings is that encapsulation of the complex bound by the face-to-face σ-hole···σ-hole stacking interaction can tune the electronic properties of the container.

Conformational analysis of EDTA-type chromium(III) complexes with β-propionato metal chelate rings

2002 ◽  
Vol 609 (1-3) ◽  
pp. 1-9 ◽  
Author(s):  
Sonja Grubišić ◽  
Maja Gruden ◽  
S.R. Niketić ◽  
Narumi Sakagami- Yoshida ◽  
Sumio Kaizaki
Keyword(s):  
Conformational Analysis ◽  
Metal Chelate ◽  
Chelate Rings

The Chemistry of Metal Chelate Rings. IV. Electrophilic Substitution of Optically Active Tris-acetylacetonates

1963 ◽  
Vol 2 (3) ◽  
pp. 576-580 ◽  
Author(s):  
James P. Collman ◽  
Robert P. Blair ◽  
Roger L. Marshall ◽  
Laird Slade
Keyword(s):  
Electrophilic Substitution ◽  
Metal Chelate ◽  
Optically Active ◽  
Chelate Rings

Disubstituted hydroxamic acids and the determination of vanadium

1968 ◽  
Vol 46 (2) ◽  
pp. 327-330 ◽  
Author(s):  
R. M. Cassidy ◽  
D. E. Ryan
Keyword(s):  
Extinction Coefficient ◽  
Metal Chelate ◽  
Visible Region ◽  
Hydroxamic Acids ◽  
Molecular Extinction Coefficient ◽  
Sensitivity Increase ◽  
Chelate Rings

A number of disubstituted hydroxamic acids were investigated as possible replacements for benzoylphenylhydroxylamine in the determination of vanadium; none is superior. At 378 mμ., p-phenylazobenzoylphenylhydroxylamine shows a marked sensitivity increase but selectivity is poor. In the visible region, there is an increase in molecular extinction coefficient as the reagent π system is extended; how ever, complete coplanarity of the aromatic and metal chelate rings is not possible and the increase is not large enough to be of much practical value.

Experimental and Numerical Studies on B-DNA Overstretching Transition in Presence of Sodium Ions at Physiological Temperature

2007 ◽  
Vol 121-123 ◽  
pp. 1093-1096 ◽  
Author(s):  
Hong Xia Fu ◽  
Chan Ghee Koh ◽  
Hu Chen ◽  
Chwee Teck Lim
Keyword(s):  
Optical Tweezers ◽  
Electrostatic Interactions ◽  
Electrostatic Energy ◽  
Stacking Interactions ◽  
Base Stacking ◽  
Physiological Temperature ◽  
Dna Molecule ◽  
Metropolis Monte Carlo ◽  
Dna Double Helix ◽  
Transition Force

In this paper, the effects of Na+ concentration on the overstretching transition of B-DNA molecule at physiological temperature are studied by both experimental and numerical methods. Using optical tweezers, the relationship of external force and relative extension is obtained by stretching single B-DNA molecule at 37°C. As the concentration increases from 0.909mM to 909mM, the overstretching transition force increases from 65.65 ± 1.2pN to 43.07 ± 1.2pN. An analytical expression is derived, which shows that overstretching transition force is linear with the natural logarithm of salt concentration. Based on a previous model, a three-dimensional model is proposed herein and solved by Metropolis Monte Carlo method. The bending deformation of DNA backbones, cooperativity of base-stacking interactions, electrostatic interactions, and spatial effects of DNA double helix structure are taken into account. Our key contribution is that the electrostatic energy is explicitly given as a function of folding angle and Na+ concentration. A new parameter is also introduced to account for the cooperativity of base-stacking interactions. The numerical results of this model are in good agreement with our experimental results.

Parallel stacking interactions in square-planar transition-metal complexes containing fused chelate and C6-aromatic rings

2012 ◽  
Vol 68 (3) ◽  
pp. 261-265 ◽  
Author(s):  
Dušan N. Sredojević ◽  
Dubravka Z. Vojislavljević ◽  
Zoran D. Tomić ◽  
Snežana D. Zarić
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Large Fraction ◽  
Stacking Interactions ◽  
Aromatic Rings ◽  
Metal Type ◽  
Square Planar ◽  
Planar Transition ◽  
Chelate Rings

Stacking interactions in the crystal structures of square-planar transition metal complexes from the Cambridge Structural Database with five- and six-membered chelate rings fused with C6-arom rings (arom = aromatic) were analyzed. The distribution of distances between the closest C6-arom–C6-arom and C6-arom–chelate contacts shows that in a large fraction of the intermolecular interactions the C6-arom ring of one molecule is closer to the chelate than to the C6-arom ring of the other molecule. These results indicate a possible preference of the C6-arom ring to form stacking contacts with the chelate rings. The preference is ubiquitous and does not depend on the metal type.

Five-membered metal chelate rings in complexes of palladium with 2-mercaptomethylazobenzene

1997 ◽  
Vol 7 (6) ◽  
pp. 239-240 ◽  
Author(s):  
Victor A. Kogan ◽  
Stanislav G. Kochin ◽  
Alla S. Antsyshkina ◽  
Georgii G. Sadikov ◽  
Alexander D. Garnovskii
Keyword(s):  
Metal Chelate ◽  
Chelate Rings
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