Equilibria for the isomerization of (secondary-alkyl)phenols and cyclohexylphenols

Article abstract of DOI:10.1016/0021-9614(89)90139-0

Equilibria of a series of isomerizations and trans-alkylations of alkylphenols have been investigated in the liquid phase over a wide range of temperatures.Equilibria of isomerizations connected with the displacement of a substituent on a benzene nucleus were studied for secondary-butyl, -amyl, -hexyl, and cyclohexyl-phenols, and di-(secondary-butyl)phenols.Equilibria of positional isomerization connected with the displacement of an oxyphenyl radical in an alkyl chain were investigated for oxyphenyl-pentanes, -hexanes, -octanes, and -decanes.Trans-alkylation was investigated for di- and tri-(secondary-butyl)phenols.Values of Δ_rH⁰_m and Δ_rS⁰_m were found for all investigated reactions.An analysis was made of the thermodynamic quantities for the reactions.Enthalpies of formation of isopropylphenols (IPP) in the gaseous state were calculated.The values of Δ_fH⁰_m/(kJ * mol^-1) were found at 298.15 K: o-IPP, -(175.3 +/- 2.4); p-IPP, -(175.3 +/- 2.4); m-IPP, -(175.3 +/-2.4); 2,4-di-IPP, -(254.1 +/- 2.8); 2,5-di-IPP, -(254.1 +/- 2.8); 2,6-di-IPP, -(254.1 +/- 2.8); 3,5-di-IPP, -(254.1 +/- 2.8); 2,4,6-tri-IPP, -(333.0 +/- 3.1).