Please use this identifier to cite or link to this item:
Type: Artigo
Title: Dealing with hydrogen bonding on the conformational preference of 1,3-aminopropanols: experimental and molecular dynamics approaches
Author: Batista, Patrick R.
Karas, Lucas J.
Viesser, Renan V.
Oliveira, Cynthia C. de
Gonçalves, Marcos B.
Tormena, Cláudio F.
Rittner, Roberto
Ducati, Lucas C.
Abstract: This study expands the knowledge on the conformational preference of 1,3-amino alcohols in the gas phase and in solution. By employing Fourier transform infrared spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, density functional theory (DFT) calculations, quantum theory of atoms in molecules (QTAIM), natural bond orbital (NBO) analysis, and molecular dynamics (MD), the compounds 3-aminopropan-1-ol (1), 3-methylaminopropan-1-ol (2), and 3-dimethylaminopropan-1-ol (3) are evaluated. The results show that the most stable conformation of each compound in the gas phase and in nonpolar solvents exhibited an O–H···N intramolecular hydrogen bond (IHB). Based on the experimental and theoretical OH-stretching frequencies, the IHB becomes stronger from 1 to 3. In addition, from the experimental NMR J-couplings, the IHB conformers are predominant in nonbasic solvents, representing 70–80% of the conformational equilibrium, while in basic solvents, such conformers only represent 10%. DFT calculations and QTAIM analysis in the gas phase support the occurrence of IHBs in these compounds. The MD simulation indicates that the non-hydrogen-bonded conformers are the lowest energy conformations in the solution because of molecular interactions with the solvent, while they are absent in the implicit solvation model based on density. NBO analysis suggests that methyl groups attached on the nitrogen atom affect the charge transfer energy involved in the IHB. This effect occurs mostly because of a decrease in the s-character of the LPN orbital along with weakening of the charge transfer from LPN to σ*OH, which is caused by an increase in the C–C–N bond angle
Subject: Ligação de hidrogênio
Equlíbrio conformacional
Dinâmica molecular
Country: Estados Unidos
Editor: American Chemical Society
Rights: fechado
Identifier DOI: 10.1021/acs.jpca.9b05619
Date Issue: 2019
Appears in Collections:IQ - Artigos e Outros Documentos

Files in This Item:
File Description SizeFormat 
101021acs.jpca9b05619.pdf2.62 MBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.