Conformational Equilibrium and Hydrogen Bonding in Liquid 2-Phenylethylamine Explored by Raman Spectroscopy and Theoretical Calculations

2011 ◽  
Vol 115 (14) ◽  
pp. 3060-3067 ◽  
Author(s):  
Min Xie ◽  
Yajing Qi ◽  
Yongjun Hu
Keyword(s):  
Raman Spectroscopy ◽  
Hydrogen Bonding ◽  
Conformational Equilibrium ◽  
Theoretical Calculations

High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

2021 ◽  
Author(s):  
Linfei Yang ◽  
Jianjun Jiang ◽  
Lidong Dai ◽  
Haiying Hu ◽  
Meiling Hong ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Spectroscopy ◽  
High Pressure ◽  
Structural Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Theoretical Calculations ◽  
Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

Nature of Monomeric Molybdenum(VI) Cations in Acid Solutions Using Theoretical Calculations and Raman Spectroscopy

2019 ◽  
Vol 123 (15) ◽  
pp. 3304-3311 ◽  
Author(s):  
Ning Zhang ◽  
Erich Königsberger ◽  
Siqi Duan ◽  
Ke Lin ◽  
Haibo Yi ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Theoretical Calculations ◽  
Acid Solutions

Privileged hydration sites in aromatic side chains: effect on conformational equilibrium

2017 ◽  
Vol 19 (42) ◽  
pp. 28684-28695 ◽  
Author(s):  
Belén Hernández ◽  
Fernando Pflüger ◽  
Manuel Dauchez ◽  
Mahmoud Ghomi
Keyword(s):  
Conformational Equilibrium ◽  
Theoretical Calculations ◽  
Side Chains ◽  
Aromatic Side Chains

The most energetically favourable hydration sites of aromatic (Phe, Tyr, Trp and His) side chains revealed by DFT-based theoretical calculations.

scholarly journals Conformational analysis and intramolecular interactions in monosubstituted phenylboranes and phenylboronic acids

2013 ◽  
Vol 9 ◽  
pp. 1127-1134 ◽  
Author(s):  
Josué M Silla ◽  
Rodrigo A Cormanich ◽  
Roberto Rittner ◽  
Matheus P Freitas
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Conformational Analysis ◽  
Conformational Equilibrium ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Interactions ◽  
Coupling Constant ◽  
Intramolecular Hydrogen ◽  
Phenylboronic Acids ◽  
Electron Donation

A 1 TS J F,H(O) coupling pathway, dictated by a hydrogen bond, in some 2-fluorobenzoic acids has been observed, while such an interaction does not occur in 2-fluorophenol. Thus, this work reports the conformational analysis of 2-fluorophenylboronic acid (1), in order to evaluate a possible intramolecular OH∙∙∙F hydrogen bond in comparison to an nF→pB interaction, which mimics the quantum nF→σ*OH hydrogen bond that would be expected in 2-fluorophenol. 2-Fluorophenylborane (3), which does not experience hydrogen bonding, was used to verify whether nF→pB interaction governs the conformational equilibrium in 1 due to a predominant OH∙∙∙F hydrogen bond or to other effects. A series of 2-X-phenylboranes (X = Cl, Br, NH2, PH2, OH and SH) were further computationally analyzed to search for electron donors to boron, capable of influencing the conformational equilibrium. Overall, the intramolecular OH∙∙∙F hydrogen bond in 1 is quite stabilizing and dictates the 1 h J F,H(O) coupling constant. Moreover, electron donation to the empty p orbital of boron (for noncoplanar BH2 moiety relative to the phenyl ring) is also significantly stabilizing for the NH2 and PH2 derivatives, but not enough to make the corresponding conformers appreciably populated, because of steric effects and the loss of πCC→pB resonance. Thus, the results found earlier for 2-fluorophenol about the lack of intramolecular hydrogen bonding are now corroborated.

scholarly journals Study of a Conformational Equilibrium of Lisinopril by HPLC, NMR, and DFT

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sondes Bouabdallah ◽  
Med Thaieb Ben Dhia ◽  
Med Rida Driss
Keyword(s):  
Experimental Data ◽  
Thermodynamic Parameters ◽  
Conformational Equilibrium ◽  
Theoretical Calculations ◽  
Nmr Data ◽  
Major Species ◽  
B3lyp Calculations

The isomerization of lisinopril has been investigated using chromatographic, NMR spectroscopic, and theoretical calculations. The NMR data, particularly the NOEDIFF experiments, show that the major species that was eluted first is thetransform. The proportion was 77% and 23% for thetransandcis, respectively. The thermodynamic parameters (ΔH,ΔS, andΔG) were determined by varying the temperature in the NMR experiments. The interpretations of the experimental data were further supported by DFT/B3LYP calculations.

Microwave Spectrum, Intramolecular Hydrogen Bonding and Conformational Equilibrium of trans-2-Methylcyclopropanemethanol.

1992 ◽  
Vol 46 ◽  
pp. 861-866 ◽  
Author(s):  
K.-M. Marstokk ◽  
Harald Møllendal ◽  
Sine Larsen ◽  
Carsten H. Petersen ◽  
Johan Springborg ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Conformational Equilibrium ◽  
Intramolecular Hydrogen Bonding ◽  
Microwave Spectrum ◽  
Intramolecular Hydrogen

scholarly journals Investigation of the cis–trans structures and isomerization of oligoprolines by using Raman spectroscopy and density functional theory calculations: solute–solvent interactions and effects of terminal positively charged amino acid residues

RSC Advances ◽  
2020 ◽  
Vol 10 (57) ◽  
pp. 34493-34500
Author(s):  
Mei-Chun Huang ◽  
Wei-Hao Chen ◽  
Chen-Wei Huang ◽  
Kuei-Yen Huang ◽  
Jia-Cherng Horng ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Raman Spectroscopy ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Density Functional Theory Calculations ◽  
State Density ◽  
Amino Acid Residues ◽  
Functional Theory ◽  
Solvent Interactions ◽  
Positively Charged

The low-wavenumber Raman spectra in combination with theoretical calculations via solid-state density functional theory (DFT)-D3 are displayed. The vibrational structures and interaction with solvent of poly-l-proline and the oligoproline P12 series are identified.

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