Thermochemical studies on 3-methyl-quinoxaline-2-carboxamide-1,4-dioxide derivatives: Enthalpies of formation and of N-O bond dissociation

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Gomes, JRB (Author) Other; Sousa, EA (Author) Other; Gomes, P (Author) FCUP; Vale, N (Author) FCUP; Goncalves, JM (Author) FCUP; Pandey, S (Author) Other; Acree, WE (Author) Other; Ribeiro Da Silva, MDMC (Author) FCUP

Journal

Title: Pain Medicine

Vol. 111

Pages: 2075-2080

ISSN: 1526-2375

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 14 Citations

Scopus - 15 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-004-BJF

DOI: 10.1021/jp067818c

Abstract (EN): The standard molar enthalpies of formation of the 3-methyl-N-R-2- quinoxalinecarboxamide-1,4-dioxides (R = H, phenyl, 2-tolyl) in the gas phase were derived using the values for the enthalpies of combustion of the crystalline compounds, measured by static bomb combustion calorimetry, and for the enthalpies of sublimation, measured by Knudsen effusion, at T = 298.15 K. These values have also been used to calibrate a computational procedure that has been employed to estimate the gas-phase enthalpies of formation of the corresponding 3-methyl-N-R-2-quinoxalinecarboxamides and also to compute the first, second, and mean N-O bond dissociation enthalpies in the gas phase. It is found that the size of the substituent almost does not influence the computed N-O bond dissociation enthalpies; the maximum enthalpic difference is ¿5 kJ·mol-1. © 2007 American Chemical Society.

Language: English

Type (Professor's evaluation): Scientific