Experimental and theoretical study of methyl n-hydroxybenzoates
2018; Elsevier BV; Volume: 124; Linguagem: Inglês
10.1016/j.jct.2018.04.011
ISSN1096-3626
AutoresJ. Manuel Ledo, Henoc Flores, J. Manuel Solano-Altamirano, Fernando Ramos, Julio M. Hernández‐Pérez, E. Adriana Camarillo, Brenda Rabell, M. Patricia Amador,
Tópico(s)Thermal and Kinetic Analysis
ResumoWe determined the standard molar enthalpies of formation in gas-phase, at T = 298.15 K, of the methyl 2-, 3-, and 4-hydroxybenzoates, through static bomb combustion calorimetry and thermogravimetry. The enthalpies of formation in gas phase were derived from experimental combustion energies and phase-change enthalpies. In addition, we calculated the enthalpies of formation in the gas-phase with the Gaussian G4 composite method combined with atomization reactions and a Boltzmann weighted average to account for the conformational diversity of each compound. Experimental and theoretical determinations differ by less than 2 kJ·mol−1. We found that intramolecular hydrogen bonding strongly stabilizes methyl 2-hydroxybenzoate.
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