title: Thermodynamic properties of quinoxaline-1,4-dioxide derivatives: a combined experimental and computational study.
abstract: The mean (N-O) bond dissociation enthalpies were derived for three 2-methyl-3-(R)-quinoxaline 1,4-dioxide (1) derivatives, with R = methyl (1a), ethoxycarbonyl (1b), and benzyl (1c). The standard molar enthalpies of formation in the gaseous state at T = 298.15 K for the three 1 derivatives were determined from the enthalpies of combustion of the crystalline solids and their enthalpies of sublimation. In parallel, accurate density functional theory-based calculations were carried out in order to estimate the gas-phase enthalpies of formation for the corresponding quinoxaline derivatives. Also, theoretical calculations were used to obtain the first and second N-O dissociation enthalpies. These dissociation enthalpies are in excellent agreement with the experimental results herewith reported.
authors.affiliation: Centro de Investigação em Química, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto, Portugal. mdsilva@fc.up.pt
authors.forename: Maria D M C
authors.initials: MD
authors.lastname: Ribeiro da Silva
authors.forename: José R B
authors.initials: JR
authors.lastname: Gomes
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Gonçalves
authors.forename: Emanuel A
authors.initials: EA
authors.lastname: Sousa
authors.forename: Siddharth
authors.initials: S
authors.lastname: Pandey
authors.forename: William E
authors.initials: WE
authors.lastname: Acree