INVESTIGATION OF THERMODYNAMIC PROPERTIES OF TRANS-2-CYCLOHEXYLCYCLOHEXANOL

A comprehensive study of thermodynamic properties of trans-2-cyclohexy lcyclohexanol (t-2CCOL) was carried out in this work. The subject comp ound is a by-product from the synthesis of 2-phenylphenol. The standar d molar enthalpy of combustion of t-2CCOL, found by the bomb calorimet ry method, Delta(c)H(m)(o)(cr,298.15 K) = - (7388.05 +/- 1.37) kJ.mol( -1), and the standard molar enthalpy of formation Delta(c)H(m)(o)(cr,2 98.5 K) = - (478.25 +/- 2.11) kJ.mol(-1). The molar sublimation and va porization enthalpies of t-2CCOL were measured with a heal-conduction differential microcalorimeter: Delta(cr)(g)H(m)(o)(319.5K) = (98.56 +/ - 0.52)kJ.mol(-1); Delta(i)(g)(345.8 K) = (80.31 +/- 0.34) kJ.mol(-1). Vapour pressure of t-2CCOL was measured by the integral effusion Knud sen method in the temperature range 293 K to 325 K for crystal: In(p/P a) = (37.30 +/- 0.22) - (11616 +/- 69).T-1, and in the temperature ran ge 328 K to 364 K for liquid: (p/Pa)=(34.41 +/- 0.44)- (10013 +/- 150) .T-1. The heat capacity of t-2CCOL was measured by the vacuum adiabati c calorimetry (T = 5 K to T = 338 K). The fusion temperature of t-2CCO L is 325.8 K, and the molar enthalpy of fusion is Delta(fus)H(m)(o) = (14.515 +/- 0.029) kJ.mol(-1). Standard molar thermodynamic functions of t-2CCOL in the crystalline stare at T = 298.15 K were obtained on t he basis of these measurements: C-p,m(o) = (248.68 +/- 0.99); Delta(O) (T)S(m)(o) = (263.85 +/- 1.18); Delta(O)(T)H(m)(o)/T = (130.52 +/- 0.5 1); Phi(m)(o) = (133.33 +/- 1.29) J.K-1.mol(-1). (C) 1997 Academic Pre ss Limited.