RT info:eu-repo/semantics/article T1 Picolinic and Isonicotinic Acids: A Fourier Transform Microwave Spectroscopy Study A1 Peña Calvo, María Isabel A1 Franco, Vanina G. A1 López Alonso, Juan Carlos A1 Cabezas, Carlos A1 Alonso Hernández, José Luis K1 Análisis espectral AB The rotational spectra of laser ablated picolinic and isonicotinic acids have been studied using broadband chirped pulse (CP-FTMW) and narrowband molecular beam (MB-FTMW) Fourier transform microwave spectroscopies. Two conformers of picolinic acid, s-cis-I and s-cis-II, and one conformer of isonicotinic acid have been identified through the analysis of their rotational spectra. The values of the inertial defect and the quadrupole coupling constants obtained for the most stable s-cis-I conformer of picolinic acid, evidence the formation of an O–H···N hydrogen bond between the acid group and the endocyclic N atom. The stabilization provided by this hydrogen bond compensates the destabilization energy due to the adoption of a −COOH trans configuration in this conformer. Its rs structure has been derived from the rotational spectra of several 13C, 15N, and 18O species observed in their natural abundances. Mesomeric effects have been revealed by comparing the experimental values of the 14N nuclear quadrupole coupling constants in the isomeric series of picolinic, isonicotinic, and nicotinic acids. PB American Chemical Society SN 1089-5639 YR 2014 FD 2014 LK http://uvadoc.uva.es/handle/10324/22666 UL http://uvadoc.uva.es/handle/10324/22666 LA eng NO Journal of Physical Chemistry A, 2014, 118 (48), pp 11373–11379 NO Producción Científica DS UVaDOC RD 22-nov-2024