In
this work, we determine, both experimentally and computationally,
structural and thermochemical properties of the methyl 2- and 4-methoxybenzoates.
Combustion and vaporization enthalpies of these compounds were obtained
experimentally through combustion calorimetry and thermogravimetry.
From these properties, their standard molar enthalpies of formation
in the gas phase, at T = 298.15 K, were also determined.
In addition, we computed gas-phase enthalpies of formation of methyl
2-, 3-, and 4-methoxybenzoates using the composite method Gaussian
G4, atomization reactions, and a weighted Boltzmann average. This
average was performed over the stable conformers of each compound,
and the respective Gibbs energies were used to compute the weights
for the Boltzmann average. The analyses of the electronic density
of the molecules and of noncovalent interactions were performed as
well. We found a good agreement between our experimental and computational
enthalpies of formation of methyl 2- and 4-methoxybenzoates. Finally,
we discuss the enthalpic effects, as a function of the relative position
of the methoxy and methyl groups, upon the benzoate base structure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.