Conformational Analysis of Some Aliphatic Esters Bearing a Nitrogen Atom as a Substituent

• Grant number: 16/24109-0
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2017
• End date: April 30, 2019
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: Roberto Rittner Neto
• Grantee: Roberto Rittner Neto
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The conformational analysis of some esters with a nitrogen atom as a substituent, through 1H and 13C NMR spectroscopy, infrared spectroscopy and theoretical calculations. The theoretical calculations will be performed at MP2 and DFT level of theory, using several basis sets, and including Zero-Point corrections (ZPE), available in the Gaussian-09 for the determination of the energies and geometries of the most stable conformers in the isolated form and through the IEF-PCM model to simulate the solvation effects in the conformational isomerism of the proposed compounds. The analysis of the carbonyl band (fundamental and 1st overtone) in several solvents will give the populations of the more stable rotamers in solution. The NMR spectra will provide JHH coupling constants, geminal and vicinal, involving the CH and CH2 groups, in solution, which can indicate changes in conformer populations according to the permittivity of the solvent. Values obtained from theoretical calculations of the carbonyl stretching vibration and of the coupling constants, in the studied solvents, will be compared with the experimental data in the assessment of the populations of the more stable conformers. Lastly, the contributions of the classical intramolecular interactions (steric and electrostatic) and quantum interactions (hyperconjugation) to stabilize a given conformer will be evaluated through topological analyses from the Quantum Theory of Atoms in Molecules (QTAIM) and Non Covalent Interactions (NCI), and also the Natural Bond Orbitals (NBO) analysis. A joint analysis with these techniques may allow unequivocally the main effects which are responsible for the conformer stabilities of these important systems. (AU)

Scientific publications

(8)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BARBOSA, THAIS M.; CASTANAR, LAURA; MOUTZOURI, PINELOPI; NILSSON, MATHIAS; MORRIS, GARETH A.; RITTNER, ROBERTO; TORMENA, CLAUDIO F.. Improving the Sensitivity of FESTA Methods for the Analysis of Fluorinated Mixtures. Analytical Chemistry, v. 92, n. 2, p. 2224-2228, JAN 21 2020. (14/12776-6, 15/08541-6, 15/19229-3, 16/24109-0)

SIVA, WESLLEY G. D. P.; TORMENA, CLAUDIO F.; RITTNER, ROBERTO. Revealing the Conformational Preferences of Proteinogenic Glutamic Acid Derivatives in Solution by H-1 NMR Spectroscopy and Theoretical Calculations. Journal of Physical Chemistry A, v. 122, n. 18, p. 4555-4561, MAY 10 2018. (16/24109-0, 15/08541-6, 16/12005-5)

FRANCISCO, CAMILA B.; FERNANDES, CLEVERTON S.; DE MELO, ULISSES Z.; RITTNER, ROBERTO; GAUZE, GISELE F.; BASSO, ERNANI A.. Strong hyperconjugative interactions limit solvent and substituent influence on conformational equilibrium: the case of cis-2-halocyclohexylamines. Beilstein Journal of Organic Chemistry, v. 15, p. 818-829, APR 1 2019. (16/24109-0)

FERNANDES, CLEVERTON DE S.; FRANCISCO, CAMILA B.; GAUZE, GISELE DE F.; RITTNER, ROBERTO; BASSO, ERNANI A.. Rapid Synthesis of Primary Amines from Ketones using Choline Chloride/Urea Deep Eutectic as a Reaction Medium. ORGANIC PREPARATIONS AND PROCEDURES INTERNATIONAL, NOV 2021. (16/24109-0)

BRAGA, CAROLYNE B.; SILVA, WESLLEY G. D. P.; RITTNER, ROBERTO. Conformational preferences of N-acetyl-N-methylprolineamide in different media: a H-1 NMR and theoretical investigation. NEW JOURNAL OF CHEMISTRY, v. 43, n. 4, p. 1757-1763, JAN 28 2019. (12/18567-4, 16/24109-0, 16/12005-5)

CASTANAR, LAURA; MOUTZOURI, PINELOPI; BARBOSA, THAIS M.; TORMENA, CLAUDIO F.; RITTNER, ROBERTO; PHILLIPS, ANDREW R.; COOMBES, STEVEN R.; NILSSON, MATHIAS; MORRIS, GARETH A.. FESTA: An Efficient Nuclear Magnetic Resonance Approach for the Structural Analysis of Mixtures Containing Fluorinated Species. Analytical Chemistry, v. 90, n. 8, p. 5445-5450, APR 17 2018. (16/24109-0, 14/12776-6, 15/08541-6, 15/19229-3)

BARBOSA, THAIS M.; VIESSER, RENAN V.; MARTINS, LUCAS G.; RITTNER, ROBERTO; TORMENA, CLAUDIO F.. The Antagonist Effect of Nitrogen Lone Pair: (3)J(HF) versus (5)J(HF). ChemPhysChem, v. 19, n. 11, p. 1358-1362, JUN 5 2018. (16/24109-0, 15/08541-6, 14/12776-6, 17/20890-1)

KARAS, LUCAS J.; BATISTA, PATRICK R.; VIESSER, RENAN V.; TORMENA, CLAUDIO F.; RITTNER, ROBERTO; DE OLIVEIRA, PAULO R.. Trends of intramolecular hydrogen bonding in substituted alcohols: a deeper investigation. Physical Chemistry Chemical Physics, v. 19, n. 25, p. 16904-16913, JUL 7 2017. (16/24109-0, 15/08541-6, 12/12414-1)