Standard enthalpies of formation of 2,6-di-tert-butyl-4-methylphenol and 3,5-di-tert-butylphenol and their phenoxy radicals

• Type: Article in International Scientific Journal
• Date: 2001

Authors

da Silva, MAVR (Author) FCUP; Matos, MAR (Author) FCUP; Miranda, MS (Author) FCUP; Sousa, MHFA (Author) Other; dos Santos, RMB (Author) Other; Bizarro, MM (Author) Other; Simoes, JAM (Author) Other

Journal

Title: Structural Chemistry

Vol. 12

Pages: 171-181

ISSN: 1040-0400

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 21 Citations

Scopus - 19 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-000-W20

DOI: 10.1023/a:1016600727116

Abstract (EN): The standard (p(o) = 0.1 MPa) enthalpies of formation of 2,6-di-tert-butyl-4-methylphenol and 3,5-di-tert-butylphenol in the gaseous phase, -315.5 +/- 4.4 kJ mol(-1) and -312.7 +/- 4.6 kJ mol(-1), respectively, were derived from the standard enthalpies of combustion, in oxygen, at 298.15 K, measured by static bomb combustion calorimetry, and from the standard enthalpies of sublimation, at 298.15 K, measured by Calvet microcalorimetry. The O-H bond dissociation enthalpies in those compounds were determined in benzene by photoacoustic calorimetry, leading to the standard enthalpies of formation of the gaseous phenoxy radicals: -189 +/- 8 kJ mol(-1) and -154 +/- 6 kJ mol(-1), respectively. These results were used to calculate enthalpies of substituent redistribution reactions, which are proposed as a method to estimate new data for substituted phenols.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11