Thermochemical and conformational study of optical active phenylbenzazole derivatives

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Silva, ALR (Author) FCUP; Matos, MAR (Author) FCUP; Victor M F Morais (Author) ICBAS; Maria D M C R Ribeiro da Silva (Author) FCUP

Journal

Title: Journal of Chemical Thermodynamics

Vol. 116

Pages: 7-20

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 8 Citations

Other information

Authenticus ID: P-00M-XKT

DOI: 10.1016/j.jct.2017.08.017

Abstract (EN): The energetic study of 2-phenylbenzoxazole (PBO), 2-phenylbenzothiazole (PBT), 2-(2-hydroxyphenyl) benzoxazole (HBO) and 2-(2-hydroxyphenyl) benzothiazole (HBT) has been developed either using experimental techniques or computational calculations. The enthalpies of combustion and of sublimation of these compounds were determined and the gas-phase standard molar enthalpies of formation were derived. The experimental techniques used were static or rotating bomb combustion calorimetry, high temperature Calvet microcalorimetry and/or the Knudsen-effusion method. Additionally, we have obtained the gas-phase standard molar enthalpies of formation of these compounds, as well of 2-(2-hydroxyphenyl) benzimidazole (HBI), through high level ab initio calculations, at the G3(MP2)//B3LYP level. The computational study of the molecular structures of all these compounds has been carried out and four possible conformers were observed for the molecules of each compound, where the keto tautomers have always higher energy than the enol forms. Furthermore, the energetic effects associated to the presence of the hydroxyl group on the core of the 2-phenylbenzazole rings, in particular the hydrogen bond network, were also evaluated. (C) 2017 Elsevier Ltd.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 14