Chemical thermodynamic properties for 1-alkanethiols

The thermodynamic quantities (G s - H 0 o ) T , (H s - H 0 o ) T , Hs - H0o, Ss, and Cs were evaluated for the solid and liquid states of ethanethiol, 1-pentanethiol, 1-hexanethiol, 1-heptanethiol, and 1-decanethiol in the range 10 to 370 K. The molar entropies So were evaluated for the ideal gas states at 298.15 K of 1-pentanethiol, 1-hexanethiol, 1-heptanethiol, and 1-decanethiol. Values for heat capacity, enthalpy of fusion, triple point temperature, and purity were determined by adiabatic calorimetric measurements. The experimentally determined average entropy increments per methylene group at 298.15 K in liquid and ideal gas states, 7.78 and 9.30 cal K−1 mol−1, respectively, are very likely constant for alkanethiols above 1-pentanethiol, and the increments agree satisfactorily with those for n-alkanes, alkyl-sustituted cyclopentanes, and alkyl-substituted cyclohexanes.