When hydrogen bonding overcomes Coulomb repulsion: from kinetic to thermodynamic stability of cationic dimers

2019 ◽  
Vol 21 (16) ◽  
pp. 8215-8220 ◽  
Author(s):  
T. Niemann ◽  
P. Stange ◽  
A. Strate ◽  
R. Ludwig
Keyword(s):  
Hydrogen Bonding ◽  
Quantum Chemical Calculations ◽  
Long Range ◽  
Thermodynamic Stability ◽  
Quantum Chemical ◽  
Short Range ◽  
Coulomb Repulsion ◽  
Molecular Ions ◽  
Electrostatic Repulsion ◽  
Dispersion Forces

“Coulomb explosion” prevented! Quantum chemical calculations of dimers of like-charged molecular ions show that Coulomb repulsion can be overcome by hydrogen bonding and dispersion forces. Quantum-type short-range attraction wins over classical long-range electrostatic repulsion providing the first thermodynamically stable cationic dimer.

Weak intramolecular and intermolecular hydrogen bonding of benzyl alcohol, 2-phenylethanol and 2-phenylethylamine in the adsorption on graphitized thermal carbon black

2015 ◽  
Vol 17 (37) ◽  
pp. 24282-24293 ◽  
Author(s):  
V. V. Varfolomeeva ◽  
A. V. Terentev
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Carbon Black ◽  
Benzyl Alcohol ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Intermolecular Hydrogen Bonding ◽  
Weak Hydrogen Bond ◽  
Graphitized Thermal Carbon Black ◽  
Flexible Molecules

The present paper discusses the contemporary state of the studies of the weak hydrogen bond contribution to the adsorption of flexible molecules. We formulated the problems which can be solved today only using the NCI method and quantum chemical calculations.

Hydrogen-Bonding and the Dissolution Mechanism of Uracil in an Acetate Ionic Liquid: New Insights from NMR Spectroscopy and Quantum Chemical Calculations

2013 ◽  
Vol 117 (15) ◽  
pp. 4109-4120 ◽  
Author(s):  
João M. M. Araújo ◽  
Ana B. Pereiro ◽  
José N. Canongia Lopes ◽  
Luís P. N. Rebelo ◽  
Isabel M. Marrucho
Keyword(s):  
Ionic Liquid ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Dissolution Mechanism

Problems with a conformation assignment of aryl-substituted resorc[4]arenes

2011 ◽  
Vol 76 (10) ◽  
pp. 1199-1222 ◽  
Author(s):  
Jakub Kaminský ◽  
Hana Dvořáková ◽  
Jan Štursa ◽  
Jitka Moravcová
Keyword(s):  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Quantum Chemical Calculations ◽  
Dynamic Process ◽  
Quantum Chemical ◽  
Energy Barrier ◽  
Π Interactions ◽  
Temperature Range ◽  
Acid Catalyzed

Acid-catalyzed condensation of resorcinol with 3,5-diisopropoxybenzaldehyde and 3,5-dihydroxybenzaldehyde afforded aryl substituted resorc[4]arenes 1a and 1b, respectively. All 16 hydroxyls in 1b were acetylated providing resorc[4]arene 1c. The conformational behaviour of 1a, 1b and 1c was studied by NMR spectroscopy and quantum chemical calculations. It was found that the stabilization of their conformations is an effect of competing π-π and OH-π interactions, hydrogen bonding and steric features, respectively. As a result, C2 symmetrical boat conformations 1a, 1b and 1c with aryls in axial positions were identified in all cases. In case of 1c also the formation of C2 symmetrical conformation with aryls in equatorial positions (boat-eq) was identified. Moreover, compounds 1a and 1b being able to create hydrogen bonds, adopt also symmetrical C4 crown conformations. For 1c(boat-ax), the boat-boat conversion with energy barrier of 80 kJ/mol was observed, while the 1c(boat-eq) was found to be rigid in the whole accessible temperature range. Both conformers of 1c exhibit also second dynamic process – rotation of bridge aryl rings (ΔG‡ = 66 kJ/mol).

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