Conformational cis- and trans- transitions in the ir spectra of behenic acid
Mikhail D. Moskvitin¹
Lev M. Babkov²
Alexey V. Larionov²
¹ Yuri Gagarin Saratov State University, Saratov, Russia
² Nikolay Chernyshevsky Saratov State University, Saratov, Russia
Abstract
In the IR spectra of behenic acid obtained over the temperature range of 11 to 365 K, differences are observed that may be associated with conformational changes. To confirm this hypothesis, structural-dynamic models of the cis- and trans-conformers of behenic acid monomers and dimers were developed using density functional theory (DFT) at the B3LYP/6-31G(d) level. Adiabatic potential parameters for the cis- and trans-conformers were calculated, including their minimum energies, optimized geometrical structures, dipole moments, force constants, and IR spectra within the harmonic approximation. The hydrogen bond energy was computed and its influence on the IR spectrum of behenic acid was evaluated. Based on the molecular modeling analysis, it was established that the conformational transition between cis- and trans-forms, which may occur upon heating, significantly affects the IR spectrum of behenic acid, particularly the vibrations of the dimer ring formed by hydrogen bonding.
Speaker
Moskvitin Michail
Saratov State Technical University
Russia
Discussion
Ask question
