Thermochemical properties of branched alkylsubstituted benzenes

✍ Scribed by Sergey P. Verevkin

• Book ID: 102578347
• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 188 KB
• Volume: 30
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.1998.0370

✦ Synopsis

The standard pЊ s 0.1 MPa molar enthalpies of formation ⌬ H l or cr at the temperature f m Ts298.15 K were measured using combustion calorimetry for tert-butylbenzene, 4-methyl-1-tert-butylbenzene, 3,5-dimethyl-1-tert-butylbenzene, 5-methyl-1,3-di-tert-butylbenzene, and 1,4-di-tert-butylbenzene. The standard molar enthalpies of vaporization ⌬ g H T , or sublimation l m

⌬ g H T , of these compounds, and also of 3-methyl-1-tert-butylbenzene, 1,3-di-tertcr m butylbenzene, and 1,3,5-tri-tert-butylbenzene were obtained from the temperature function of the vapour pressure measured in a flow system. Enthalpies of fusion ⌬ l H T of solid cr m compounds were measured by d.s.c. Strain enthalpies of branched alkylbenzenes were derived from the measured enthalpies of formation of the gaseous compounds. These experimental results, together with the data available from the literature, provided a quantitative understanding of the interrelations of structure and energetics of alkylbenzenes, and a further improvement on the group-contribution methodology for estimation of thermodynamic properties of organic compounds.