Energetic Study Applied to the Knowledge of the Structural and Electronic Properties of Monofluorobenzonitriles

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Manuel A V R Ribeiro da Silva (Author) FCUP; Manuel J S Monte (Author) FCUP; Ines M Rocha (Author) Other; Alvaro Cimas (Author) Other

Journal

Title: Journal of Organic Chemistry

Vol. 77

Pages: 4312-4322

ISSN: 0022-3263

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 12 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-002-A54

DOI: 10.1021/jo3002968

Abstract (EN): The present work reports an energetic and structural study of 2-fluoro-, 3-fluoro-, and 4-fluorobenzonitrile. The standard molar enthalpies of formation, in the condensed phase, of the three isomers were derived from the standard molar energies of combustion, in oxygen, at T = 298.15 K. The standard molar enthalpies of vaporization or sublimation (for 4-fluorobenzonitrile), at T = 298.15 K, were measured using high-temperature Calvet microcalorimetry. The combination of these two parameters yields the standard molar enthalpies of formation in the gaseous phase. The vapor-pressure study of the referred compounds was performed by a static method, and the enthalpies of phase transition derived from the application of the Clarke and Glew equation. Theoretically estimated gas-phase enthalpies of formation, basicities, proton and electron affinities, and adiabatic ionization enthalpies were calculated from the G3MP2B3 level of theory. In order to evaluate the electronic properties, the geometries were reoptimized at MP2/cc-pVTZ level, and the QTAIM and NICS were computed. On the basis of the donor-acceptor system, another approach for evaluating the electronic effect for these compounds, using the NBO is suggested. The UV-vis spectroscopy study for the three isomers was performed. The intensities and the band positions were correlated with the thermodynamic properties calculated computationally.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11