Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7628979 | Journal of Pharmaceutical and Biomedical Analysis | 2016 | 37 Pages |
Abstract
The thermodynamic parameters (ÎH, ÎS and ÎG) were determined by varying the temperature in the NMR experiments. At the coalescence temperature, we can evaluate the isomerization barrier to the rotation (ÎGâ ) around the amide bond. Using dynamics chromatography and an unified equation introduced by Trap, we can determine isomerization rate constants and Gibbs activation energies. Molecular mechanics calculations also provided evidence for the presence of low energy conformers for the ACE due to restricted amide rotation. With the value of barriers (ÎE) between them of the order of (20Â kJÂ molâ1), which is in agreement with the dynamic NMR results and DFT calculations.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
S. Bouabdallah, M.T. Ben Dhia, M.R. Driss, S. Touil,