Substituent and Solvent Effects on the Proton Transfer Equilibrium in Anils and Azo Derivatives of Naphthol. Multinuclear NMR Study and Theoretical Calculations

ALARCON, SERGIO; OLIVIERI, ALEJANDRO; SANZ, DIONISIA; CLARAMUNT, ROSA; ELGUERO, JOSE

Journal of Molecular Structure

Elsevier

Lugar: AMSTERDAM; Año: 2004 vol. 705 p. 1 - 9

The tautomeric equilibrium due to proton transfer is compared in a series of anils of 2-hydroxynaphthalene-1-carbaldehyde and azo derivatives of 2-naphthol. Although structurally similar, these systems suffer different substituent effects on the solution-state proton transfer properties. The comparative study was performed using 1H, 13C and 15N NMR spectroscopy in a variety of solvents. Hartree-Fock ab initio calculations involving relative stability of tautomers and full geometry optimization for the ground state are in agreement with the experimental observations.