Equilibria of isomeric transformations of alkylbiphenyls

Article abstract of DOI:10.1016/0021-9614(87)90137-6

Equilibria of mutual transformations of mono-, di-, and tri-alkylbiphenyls (ABP) were investigated in the liquid phase at 308 to 423 K.On the basis of experimental equilibrium constants, values of Δ_rH_m⁰/(kJ * mol^-1) and Δ_rS_m⁰/(J * K^-1 * mol^-1) were calculated.Below are given correspondingly: reaction, compound and values for Et-BP (I), i-Pr-BP (II), and t-Bu-BP (III): 4-ABP = 3-ABP, I, 0.23, 5.76; II, (0.45+/-0.4), (5.72+/-1.13); III, (0.48+/-0.53), (4.83+/-0.53); 2-ABP = 4-ABP, I, -3,3, -5.76; II, -12.6, -5.76; III, -15.4, -5.76; 3,5-di-ABP = 3,3'-di-ABP, I, -0.1, 5.76; II, (0+/-0.60), (5.98+/-1.65); III, (-1.34+/-0.67), (4.48+/-1.87); 3,3'-di-ABP = 3,4'-di-ABP, I, -0.37, 0; II, (-0.64+/-1.6), (-0.48+/-4.6); III, (-0.90+/-0.39), (0+/-1.08); 4,4'-di-ABP = 4,3'-di-ABP, I, 0.24, 11.53; II, (0.47+/-0.06), (11.88+/-0.15); III, (0.35+/-2.2), (11.37+/-6.23).The joint processing of the above results gave the values of Δ_rH_m⁰/(kJ * mol^-1) and Δ_rS_m⁰/(J * K^-1 * mol^-1) for meta-to-para-transformations of ABP: I, 0.33, 0; II, (0.59+/-0.76), (0.31+/-2.12); III, (0.71+/-1.34), (-0.37+/-3.78).