Unraveling non-covalent interactions within flexible biomolecules: from electron density topology to gas phase spectroscopy

2014 ◽  
Vol 16 (21) ◽  
pp. 9876 ◽  
Author(s):  
R. Chaudret ◽  
B. de Courcy ◽  
J. Contreras-García ◽  
E. Gloaguen ◽  
A. Zehnacker-Rentien ◽  
...  
Keyword(s):  
Gas Phase ◽  
Electron Density ◽  
Electron Density Topology ◽  
Density Topology ◽  
Non Covalent Interactions ◽  
Gas Phase Spectroscopy ◽  
Covalent Interactions

NON COVALENT INTERACTIONS IN LARGE DIAMONDOID DIMERS IN THE GAS PHASE - A MICROWAVE STUDY

2017 ◽  
Author(s):  
Cristobal Perez ◽  
Melanie Schnell ◽  
Peter Schreiner ◽  
Norbert Mitzel ◽  
Yury Vishnevskiy ◽  
...  
Keyword(s):  
Gas Phase ◽  
Non Covalent Interactions ◽  
Covalent Interactions

scholarly journals Non covalent interactions stabilizing the chiral dimer of CH2ClF: a rotational study

2019 ◽  
Vol 21 (7) ◽  
pp. 3695-3700 ◽  
Author(s):  
Laura B. Favero ◽  
Assimo Maris ◽  
Sonia Melandri ◽  
Paolo Ottaviani ◽  
Walther Caminati
Keyword(s):  
Spectral Analysis ◽  
Gas Phase ◽  
Rotational Spectroscopy ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Two C–H⋯Cl–C and one C–H⋯F–C bonds stabilize (by 5.9 kJ mol−1) the dimer of chlorofluoromethane observed by rotational spectroscopy in the gas phase. The spectral analysis is complicated by the quadrupolar effects of the two nonequivalent Cl nuclei.

scholarly journals Understanding the Reactivity of Trimethylsilyldiazoalkanes Participating in [3+2] Cycloaddition Reactions towards Diethylfumarate with a Molecular Electron Density Theory Perspective

Organics ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 3-18
Author(s):  
Luis R. Domingo ◽  
Nivedita Acharjee ◽  
Haydar A. Mohammad-Salim
Keyword(s):  
Electron Density ◽  
Energy Cost ◽  
Trimethylsilyl Group ◽  
Gibbs Energies ◽  
Molecular Electron ◽  
One Step ◽  
Molecular Electron Density Theory ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Step Mechanism

A Molecular Electron Density Theory (MEDT) study is presented here for [3+2] cycloaddition (32CA) reactions of three trimethylsilyldiazoalkanes with diethyl fumarate. The presence of silicon bonded to the carbon of these silyldiazoalkanes changes its structure and reactivity from a pseudomonoradical to that of a zwitterionic one. A one-step mechanism is predicted for these polar zw-type 32CA reactions with activation enthalpies in CCl4 between 8.0 and 19.7 kcal·mol−1 at the MPWB1K (PCM)/6-311G(d,p) level of theory. The negative reaction Gibbs energies between −3.1 and −13.2 kcal·mole−1 in CCl4 suggests exergonic character, making the reactions irreversible. Analysis of the sequential changes in the bonding pattern along the reaction paths characterizes these zw-type 32CA reactions. The increase in nucleophilic character of the trimethylsilyldiazoalkanes makes these 32CA reactions more polar. Consequently, the activation enthalpies are decreased and the TSs require less energy cost. Non-covalent interactions at the TSs account for the stereoselectivity found in these 32CA reactions involving the bulky trimethylsilyl group.

A Detailed Classification of Three-Centre Two-Electron Bonds

2020 ◽  
Vol 73 (8) ◽  
pp. 767
Author(s):  
Sharon Priya Gnanasekar ◽  
Elangannan Arunan
Keyword(s):  
Electron Density ◽  
Natural Bond Orbital ◽  
Nbo Analysis ◽  
Atoms In Molecules ◽  
Electron Density Topology ◽  
Density Topology ◽  
Detailed Classification ◽  
Theoretical Analyses ◽  
The Way

We evaluate the three-centre two-electron (3c-2e) bonds using atoms in molecules (AIM) and natural bond orbital (NBO) theoretical analyses. They have been classified as ‘open (V)’ or ‘closed (Δ)’, depending on how the three centres were bonded. Herein, we show that they could be classified as V, L, Δ, Y, T and I (linear) arrangements depending on the way the three centres are bonded. These different structures are found in B2H6 (V), CH5+ (V), Me-C2H2+ (L), B3+ (Δ), C3H3+ (Δ), H3+ (Y), 2-norbornyl+ (T), SiH5+ (T), and Al2H7− (I). Our results suggest that CH3Li2+ does not contain a 3c-2e bond according to NBO analysis. Therefore, we propose that 3c-2e bonds are classified more accurately as V, L, Δ, Y, T, or I, based on the electron density topology.

Revealing the electrophilicity of N-Ac indoles with FeCl3: a mechanistic study

2017 ◽  
Vol 53 (43) ◽  
pp. 5834-5837 ◽  
Author(s):  
Rodolphe Beaud ◽  
Raj Kumar Nandi ◽  
Alejandro Perez-Luna ◽  
Régis Guillot ◽  
Didier Gori ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Electron Density ◽  
Mechanistic Study ◽  
Electron Density Topology ◽  
Density Topology ◽  
Iron Trichloride

The puzzling hydroarylation of N-Ac indoles promoted by iron trichloride involves a doubly activated intermediate: as supported by the electron density topology of a crystal, IR monitoring, and DFT calculations.

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