1
|
Kuş N, Sharma A, Peña I, Bermúdez MC, Cabezas C, Alonso JL, Fausto R. Conformers of β-aminoisobutyric acid probed by jet-cooled microwave and matrix isolation infrared spectroscopic techniques. J Chem Phys 2015; 138:144305. [PMID: 24981533 DOI: 10.1063/1.4799456] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
β-aminoisobutyric acid (BAIBA) has been studied in isolation conditions: in the gas phase and trapped into a cryogenic N2 matrix. A solid sample of the compound was vaporized by laser ablation and investigated through their rotational spectra in a supersonic expansion using two different spectroscopic techniques: broadband chirped pulse Fourier transform microwave spectroscopy and conventional molecular beam Fourier transform microwave spectroscopy. Four conformers with structures of two types could be successfully identified by comparison of the experimental rotational and (14)N nuclear quadruple coupling constants with those predicted theoretically: type A, bearing an OH⋯N intramolecular hydrogen bond and its carboxylic group in the trans geometry (H-O-C=O dihedral ∼180°), and type B, having an NH⋯O bond and the cis arrangement of the carboxylic group. These two types of conformers could also be trapped from the gas phase into a cryogenic N2 matrix and probed by Fourier transform infrared (IR) spectroscopy. In situ irradiation of BAIBA isolated in N2 matrix of type B conformers using near-IR radiation tuned at the frequency of the O-H stretching 1st overtone (∼6930 cm(-1)) of these forms allowed to selectively convert them into type A conformers and into a new type of conformers of higher energy (type D) bearing an NH⋯O=C bond and a O-H "free" trans carboxylic group.
Collapse
Affiliation(s)
- N Kuş
- Department of Chemistry, University of Coimbra, P-3004-535 Coimbra, Portugal
| | - A Sharma
- Department of Chemistry, University of Coimbra, P-3004-535 Coimbra, Portugal
| | - I Peña
- Grupo de Espectroscopia Molecular (GEM), Unidad Asociada CSIC, Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Universidad de Valladolid, 47005 Valladolid, Spain
| | - M C Bermúdez
- Grupo de Espectroscopia Molecular (GEM), Unidad Asociada CSIC, Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Universidad de Valladolid, 47005 Valladolid, Spain
| | - C Cabezas
- Grupo de Espectroscopia Molecular (GEM), Unidad Asociada CSIC, Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Universidad de Valladolid, 47005 Valladolid, Spain
| | - J L Alonso
- Grupo de Espectroscopia Molecular (GEM), Unidad Asociada CSIC, Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Universidad de Valladolid, 47005 Valladolid, Spain
| | - R Fausto
- Department of Chemistry, University of Coimbra, P-3004-535 Coimbra, Portugal
| |
Collapse
|
2
|
Saad ZB, Chong SX, Wong ZX, Abdallah HH, Al-Saadi AA. Structural properties and vibrational spectra of 2-formyloxazole and its 2-thioformyl and 2-selenoformyl derivatives. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2011.10.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
3
|
Lopes S, Nunes CM, Gómez-Zavaglia A, Pinho e Melo TM, Fausto R. Structure and photochemical behaviour of 3-azido-acrylophenones: a matrix isolation infrared spectroscopy study. Tetrahedron 2011. [DOI: 10.1016/j.tet.2011.07.084] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
4
|
Lopes S, Nunes CM, Gómez-Zavaglia A, Pinho e Melo TMVD, Fausto R. Photochemistry and Vibrational Spectra of Matrix-Isolated Methyl 4-Chloro-5-phenylisoxazole-3-carboxylate. J Phys Chem A 2011; 115:1199-209. [DOI: 10.1021/jp110705c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Susy Lopes
- Department of Chemistry, University of Coimbra, P-3004-535 Coimbra, Portugal
| | - Cláudio M. Nunes
- Department of Chemistry, University of Coimbra, P-3004-535 Coimbra, Portugal
| | - Andrea Gómez-Zavaglia
- Department of Chemistry, University of Coimbra, P-3004-535 Coimbra, Portugal
- Centro de Investigación y Desarrollo en Criotecnología de Alimentos (Conicet La Plata, UNLP), RA-1900, Argentina
| | | | - Rui Fausto
- Department of Chemistry, University of Coimbra, P-3004-535 Coimbra, Portugal
| |
Collapse
|