Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Experimental and theoretical evaluation on the conformational behavior of L-aspartic acid dimethyl ester and its N-acetylated derivative

Full text
Author(s):
Braga, Carolyne B. [1] ; Ducati, Lucas C. [2] ; Rittner, Roberto [1]
Total Authors: 3
Affiliation:
[1] Univ Estadual Campinas, Phys Organ Chem Lab, Inst Chem, BR-13083970 Campinas, SP - Brazil
[2] Univ Sao Paulo, Inst Chem, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: RSC ADVANCES; v. 5, n. 23, p. 18013-18024, 2015.
Web of Science Citations: 6
Abstract

In this work the conformational preferences of L-aspartic acid dimethyl ester (AspOMe) and its N-acetylated derivative (AcAspOMe) were evaluated through spectroscopic data and theoretical calculations. Unlike amino acids, their corresponding amino ester derivatives do not exhibit a zwitterionic structure and are soluble in most organic solvents, enabling their studies in these media. Thus, the conformers of AspOMe and AcAspOMe were theoretically determined both in isolated phase and in solution (IEF-PCM model) at the omega B97X-D/aug-cc-pVTZ level. A joint analysis of the experimental and theoretical (3)J(HH) coupling constants in several aprotic solvents allowed assigning the most stable conformers, showing excellent agreement between these approaches. Also, IR spectroscopy allowed us to obtain quantitative data on AcAspOMe conformer populations in different solvents. Natural bond orbital (NBO) analysis indicated that both steric and hyperconjugative contributions count in determining the relative conformer stabilities of these compounds. Intramolecular hydrogen bonding, characterized by Quantum Theory of Atoms in Molecules (QTAIM) and Non-Covalent Interactions (NCI) methodologies, represents only a secondary factor to drive the stabilities of AspOMe and AcAspOMe conformers. (AU)

FAPESP's process: 12/18567-4 - Conformational investigation of amino acid derivatives and corresponding intramolecular interactions through NMR and IR spectroscopies and theoretical calculations
Grantee:Carolyne Brustolin Braga
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 12/03933-5 - Conformational equilibria and intramolecular interactions for a series of amino-acids: theoretical and experimental approaches
Grantee:Roberto Rittner Neto
Support Opportunities: Regular Research Grants