Hydrogen-Bonding Interactions of (CF3)3CH and (CF3)3C−in the Gas Phase. An Experimental (FT-ICR) and Computational Study

2009 ◽  
Vol 113 (23) ◽  
pp. 6422-6429 ◽  
Author(s):  
Andrés Guerrero ◽  
Rebeca Herrero ◽  
Juan Z. Dávalos ◽  
Ivar Koppel ◽  
José-Luis M. Abboud ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Computational Study ◽  
Hydrogen Bonding Interactions ◽  
Ft Icr

scholarly journals A computational study on how structure influences the optical properties in model crystal structures of amyloid fibrils

2017 ◽  
Vol 19 (5) ◽  
pp. 4030-4040 ◽  
Author(s):  
Luca Grisanti ◽  
Dorothea Pinotsi ◽  
Ralph Gebauer ◽  
Gabriele S. Kaminski Schierle ◽  
Ali A. Hassanali
Keyword(s):  
Optical Properties ◽  
Hydrogen Bonding ◽  
Proton Transfer ◽  
Crystal Structures ◽  
Amyloid Fibrils ◽  
Computational Study ◽  
Model Systems ◽  
Hydrogen Bonding Interactions ◽  
Model Crystal ◽  
Different Types

Different types of hydrogen bonding interactions that occur in amyloids model systems and molecular factors that control the susceptibility of the protons to undergo proton transfer and how this couples to the optical properties.

Spectroscopic investigations of hydrogen bonding interactions in the gas phase. II. The determination of the geometry and potential constants of the hydrogen-bonded heterodimer CH 3 CN • • • HF from its microwave rotational spectrum

1980 ◽  
Vol 370 (1741) ◽  
pp. 239-255 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Spectroscopic Constants ◽  
Rotational Spectrum ◽  
Hydrogen Bonding Interactions ◽  
Isotopic Species ◽  
Microwave Rotational Spectrum ◽  
Vibration Rotation ◽  
Hydrogen Bonded

The microwave rotational spectrum of the hydrogen-bonded heterodimer CH 3 CN • • • HF has been identified and shown to be characteristic of a symmetric top. A detailed analysis of several rotational transitions for a variety of isotopic species gives the spectroscopic constants summarized in the following table: Rotational constants/MHz, vibration-rotation constants/MHz and vibrational separations/cm -1 of CH 3 CN • • • HF

scholarly journals Simulating Absorption Spectra of Flavonoids in Aqueous Solution: A Polarizable QM/MM Study

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5853
Author(s):  
Sulejman Skoko ◽  
Matteo Ambrosetti ◽  
Tommaso Giovannini ◽  
Chiara Cappelli
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Force Field ◽  
Absorption Spectra ◽  
Computational Study ◽  
Md Simulations ◽  
Quantum Mechanical ◽  
Hydrogen Bonding Interactions

We present a detailed computational study of the UV/Vis spectra of four relevant flavonoids in aqueous solution, namely luteolin, kaempferol, quercetin, and myricetin. The absorption spectra are simulated by exploiting a fully polarizable quantum mechanical (QM)/molecular mechanics (MM) model, based on the fluctuating charge (FQ) force field. Such a model is coupled with configurational sampling obtained by performing classical molecular dynamics (MD) simulations. The calculated QM/FQ spectra are compared with the experiments. We show that an accurate reproduction of the UV/Vis spectra of the selected flavonoids can be obtained by appropriately taking into account the role of configurational sampling, polarization, and hydrogen bonding interactions.

Erratum

1986 ◽  
Vol 404 (1826) ◽  
pp. 147-147 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Ground State ◽  
Hyperfine Coupling ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Spectroscopic Investigations ◽  
Hydrogen Bonding Interactions ◽  
Hydrogen Bonded

Proc. R. Soc. Lond. A 401, 327-347 (1985) Spectroscopic investigations of hydrogen bonding interactions in the gas phase. X. Properties of the hydrogen-bonded heterodimer HCN⋯HF determined from hyperfine coupling and centrifugal distortion effects in its ground-state rotational spectrum By A. C. Legon, D. J. Millen and L. C. Willoughby On p. 327, at the end of the abstract, for 0.14 Å read 0.014 Å. On p. 343, line 7, for 0.025 Å read 0.014 Å. On p. 344, line 27, for 25.4° read 21.7°; line 33, for 6.6° read 2.9°. On p. 347, line 12, for 0.025 Å read 0.014 Å.

A computational study of the SNAr reaction of 2-ethoxy-3,5-dinitropyridine and 2-methoxy-3,5-dinitropyridine with piperidine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Oluwakemi A. Oloba-Whenu ◽  
Idris O. Junaid ◽  
Chukwuemeka Isanbor
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Density Functional ◽  
Computational Study ◽  
Density Functional Theory Method ◽  
Basis Set ◽  
Slow Step ◽  
Functional Theory ◽  
Snar Reaction ◽  
Hybrid Density Functional

AbstractA computational study of the chemical kinetics and thermodynamics study of the SNAr between 3,5-dinitroethoxypyridine 1a and 3,5-dinitromethoxypyridine 1b with piperidine 2 in the gas phase is reported using hybrid density functional theory method B3PW91 and 6–31G(d,p) basis set. The reaction was modeled via both the catalyzed and base-catalyzed pathways which proceeded with the initial attack of the nucleophile 2 on the substrates 1 to yield the Meisenheimer complex intermediate that is stabilized with hydrogen bonding. Calculations show that the reaction goes via the formation and decomposition of a Meisenheimer complex, which was observed to be stabilized by hydrogen bonding. Along the uncatalyzed pathway, the decomposition of the Meisenheimer complex was the slow step and requires about 28 kcal/mol. This barrier was reduced to about 14.8 kcal/mol with the intervention of the base catalyst, thus making the formation of the Meisenheimer complex rate determining. All reactions were calculated to be exothermic, about −6.5 kcal/mol and −0.6 kcal/mol, respectively, for the reaction of 1a and 1b with 2.

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