Vibrational energy relaxation of the amide I mode of N-methylacetamide in D₂O studied through Born-Oppenheimer molecular dynamics.
The vibrational relaxation of the amide I mode of deuterated N-methylacetamide in D2O solution is studied through nonequilibrium simulations using the semiempirical Born-Oppenheimer molecular dynamics (SEBOMD) approach to describe the whole solute-solvent system. Relaxation pathways and lifetimes are determined using the instantaneous normal mode (INM) analysis. The relaxation of the amide I mode is characterized by three different time scales; most of the excess energy (80%) is redistributed through intramolecular vibrational energy redistribution processes, with a smaller contribution (20%) of intermolecular energy flowing into the solvent. The amide II mode is found to contribute modestly (7%) to the relaxation mechanism. The amide I mode and the total vibrational energy decay curves obtained using SEBOMD and INM are in satisfactory agreement with the experimental measurements.
Departamento de Química Física, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia , 30100 Murcia, Spain.
Marwa H
MH
Farag
Adolfo
A
Bastida
Manuel F
MF
Ruiz-López
Gérald
G
Monard
Francesca
F
Ingrosso
D000081:Acetamides / Q000737:chemistry*; D017666:Deuterium Oxide / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D012996:Solutions; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014732:Vibration
D000081:Acetamides; D012996:Solutions; D012997:Solvents; D017666:Deuterium Oxide; C018595:N-methylacetamide