Thermodynamic Study of Chlorobenzonitrile Isomers: A Survey on the Polymorphism, Pseudosymmetry, and the Chloro center dot center dot center dot Cyano Interaction

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

Authors

Ines M Rocha (Author) Other; Tiago L P Galvao (Author) Other; Maria D M C R Ribeiro da Silva (Author) FCUP; Manuel A V R Ribeiro da Silva (Author) Other

Journal

Title: Journal of Physical Chemistry A

Vol. 118

Pages: 1502-1510

ISSN: 1089-5639

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 11 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-009-7K3

DOI: 10.1021/jp410187q

Abstract (EN): The relationships among structural and thermodynamic properties of 2-, 3-, and 4-chlorobenzonitrile were investigated, in the present work, using several experimental techniques (Knudsen effusion, differential scanning calorimetry, and combustion calorimetry) and computational studies. The CN center dot center dot center dot Cl intermolecular interactions are weaker in 2-chlorobenzonitrile, reflecting a lower enthalpy of sublimation. The two polymorphic forms of 4-chlorobenzonitrile were observed by differential scanning calorimetry and interpreted in terms of the strength of CN center dot center dot center dot Cl intermolecular interactions. The entropic differentiation due to the pseudosymmetry observed in the crystalline packing of 2-chlorobenzonitrile was evaluated. Using adequate working reactions and the respective standard molar enthalpies of formation, in the gaseous phase, the halogen-cyano intramolecular interaction was also evaluated. The theoretically estimated gas-phase enthalpies of formation were calculated using high-level ab initio molecular orbital calculations at the G3MP2B3 and MP2/cc-pVTZ levels of theory. The computed values support very well the experimental results obtained in this work.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9