Thermochemistry of 2-methylbenzoxazole and 2,5-dimethylbenzoxazole: an experimental and computational study

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Ana L R Silva (Author) Other; Alvaro Cimas (Author) Other; Maria D M C R Ribeiro da Silva (Author) FCUP

Journal

Title: Structural Chemistry

Vol. 24

Pages: 1863-1872

ISSN: 1040-0400

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 12 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-006-JB8

DOI: 10.1007/s11224-013-0245-x

Abstract (EN): The standard (p degrees = 0.1 MPa) molar energies of combustion of 2-methylbenzoxazole and 2,5-dimethylbenzoxazole were measured by static-bomb combustion calorimetry. The standard molar enthalpies of vapourization, at T = 298.15 K, were obtained from high-temperature Calvet microcalorimetry. The experimental results enable the calculation of the standard molar enthalpies of formation in the gaseous state, at T = 298.15 K, for both compounds, being the results discussed in terms of structural and energetic contributions. The theoretically estimated gas-phase enthalpies of formation were calculated from high-level ab initio molecular orbital calculations at the G3(MP2)//B3LYP level of theory. The computed values compare very well with the experimental results obtained in this work and show that the 2,5-dimethylbenzoxazole is enthalpically the most stable compound. Furthermore, this composite approach was also used to obtain information about the gas-phase basicities, proton and electron affinities and adiabatic ionization enthalpies.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10