Affiliation:
1. Research Center, Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry (DQB), Faculty of Sciences, University of Porto (FCUP), Rua do Campo Alegre, 4169-007 Porto, Portugal
Abstract
The enthalpies of formation in the gaseous phase of methyl 3-methylanthranilate and methyl 5-methylanthranilate were determined from experimental measurements of the corresponding standard energies of combustion, obtained from combustion calorimetry, and the standard enthalpies of vaporization and sublimation, obtained from Calvet microcalorimetry and Knudsen mass-loss effusion. A computational study, using the G3(MP2)//B3LYP composite method, has also been performed for the calculation of the gas-phase standard enthalpies of formation of those two molecules at T = 298.15 K, as well as for the remaining isomers, methyl 4-methylanthranilate and methyl 6-methylanthranilate. The results have been used to evaluate and analyze the energetic effect of the methyl substituent in different positions of the ring.
Funder
Fundação para a Ciência e Tecnologia
Subject
Chemistry (miscellaneous),Analytical Chemistry,Organic Chemistry,Physical and Theoretical Chemistry,Molecular Medicine,Drug Discovery,Pharmaceutical Science