CEQUINOR   05415
CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
Unidad Ejecutora - UE
artículos
Título:
Molecular structure, experimental and theoretical 1H and 13C NMR chemical shift assignment of cyclic and acyclic α,β-unsaturated esters
Autor/es:
NORMA N. BUCETA; DIEGO RUIZ; GUSTAVO P. ROMANELLI; JUAN C. AUTINO; HELMUT DUDDECK; REINALDO PIS DIEZ; JORGE L. JIOS
Revista:
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY
Editorial:
JOHN WILEY & SONS LTD
Referencias:
Lugar: Londres; Año: 2014 vol. 27 p. 106 - 106
ISSN:
0894-3230
Resumen:
The experimental 1H and 13C NMR spectra of 13 phenyl cinnamates and four 4-methylcoumarins were investigated and their chemical shifts assigned on the basis of the two-dimensional spectra. For the unsubstituted cinnamic acid phenyl ester, optimized molecular structures were calculated at a B3LYP/6-311++G(d,p) level of theory. 1H and 13C NMR chemical shifts were also calculated with the GIAO method at the B3LYP/6-311 + G(2d,p) level of theory. The comparison between experimental and calculated NMR chemical shift suggests that the experimental spectra are formed from the superposition spectra of the two lowest energy conformers of the compound in solution. The most stable s-cis configuration found in our studies isĀ  also the conformation adopted for a related phenyl cinnamate in solid state. The experimental results were analyzed in terms of the substituent effects.