Elucidating the multiple structures of pipecolic acid by rotational spectroscopy. Issue 8 (6th December 2018)

• Record Type: Journal Article
• Authors: Simão, A.; Cabezas, C.; León, I.; Alonso, E. R.; Mata, S.; Alonso, J. L.
• Is Part Of: Physical chemistry chemical physics. Volume 21:Issue 8(2019)
• Page Start: 4155
• Page End: 4161
• Publication Date: 2018-12-06
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c8cp06120c
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The complex conformational space of the non-proteinogenic cyclic amino acid pipecolic acid has been explored in the gas phase for the first time, with 9 conformers characterized via a combination of CP-FTMW and LA-FTMW techniques, supported by theoretical data. Abstract : The complex conformational space of the non-proteinogenic cyclic amino acid pipecolic acid has been explored in the gas phase for the first time. Solid pipecolic acid samples were vaporized by laser ablation and expanded in a supersonic jet where the rotational spectral signatures owing to nine different conformers were observed by Fourier transform microwave spectroscopy. All species were identified by comparison of the experimental rotational and nuclear quadrupole coupling constants with those predicted theoretically. Observation of type-III conformers, leading to a difference when compared against the conformational behavior of the analog amino acid proline, has been interpreted by an increment in steric hindrance when increasing the number of carbons present in the ring.