Thermochemical Insights on the Conformational Energetics of Azepan and Azepan-1-ylacetonitrile

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Vera L S Freitas (Author) FCUP; Sara Leirosa (Author) Other; Rafael Notario (Author) Other; Maria D M C R Ribeiro da Silva (Author) FCUP

Journal

Title: Journal of Organic Chemistry

Vol. 79

Pages: 11583-11591

ISSN: 0022-3263

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 9 Citations

Scopus - 10 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-00A-29Y

DOI: 10.1021/jo5022376

Abstract (EN): This paper is concerned with computational and experimental thermochemical studies of azepan and azepan-1-ylacetonitrile, molecules whose flexible ring structure provides several conformational forms with low energy barriers among them. The computational study describes the energetic analysis of the six most stable conformers on the potential energy surfaces and the determination of their gas-phase standard enthalpy of formation at the reference temperature of 298.15 K. The same gas-phase enthalpic parameters are also derived from the enthalpies of formation in the liquid phase and the enthalpies of vaporization, at T = 298.15 K, determined experimentally using the combustion calorimetry and the Calvet microcalorimetry techniques, respectively. The experimental data reported in this work for the two titled compounds together with other available in the literature for related molecules enabled the establishment of an increments scheme, providing a reliable approach on the prevision of gas-phase enthalpy of formation of cyclic/acyclic hydrocarbons and amines. Complementary, natural bond orbital (NBO) calculations were also performed, allowing an advance on the analysis of the structural and reactivity behavior of these type of compounds.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9