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Heat capacities and phase-transition enthalpies measured by adiabatic calorimetry are reported for pent-1-ene (10 K to 320 K), cis -hex-2-ene (10 K to 330 K), non-1-ene (10 K to 400 K), and hexadec-1-ene (10 K to 400 K). Entropies and enthalpies relative to the crystals at T → 0 are derived. Results are compared with published heat-capacity results for less pure samples of pent-1-ene and hexadec-1-ene.

Low-temperature thermodynamic properties were measured for cyclopropylamine, cyclopentylamine, and methylenecyclobutane from 12 K to near their respective boiling temperatures. Values of molar heat capacities at saturation pressure of the condensed phases, melting temperatures, purities, and enthalpies of fusion were measured by adiabatic calorimetry. From these measurements the thermodynamic quantities, −{G s (T)−H o (0)} T , {H s (T)−H o (0)} T , { H s ( T )− H o (0)}, S s and C s , were derived for the solid and liquid states. Values at 298.15 K of the standard entropy, standard Gibbs energy of formation, and logarithm of equilibrium constant of formation for the three materials in the ideal-gas state were computed.

The low-temperature thermal properties of three dimethylindans (1,1; 4,6; and 4,7) and two tetramethylindans (1,1,4,6 and 1,1,4,7) were measured by adiabatic calorimetry from 10 to about 400 K. Properties measured included the heat capacity of the condensed phases at saturation pressure, enthalpy of fusion, triple-point temperature, and purity of sample. The 1,1,4,6-tetramethylindan exhibited a lambda transition with a peak at 191 K. The 1,1,4,7 sample formed a glass when cooled rapidly from the liquid. The glass was studied from 10 K to the transition temperature (about 160 K). The results were used to calculate thermodynamic functions at selected temperature for the condensed phases −{G 3 (T)−H°(0)} T , {H 3 (T)−H°(0)} T , {H s (T)−H°(0)},S s , C s , and the thermodynamic functions for the ideal gas.

Low-temperature calorimetric quantities were determined for 2,3-dimethylpentane, 3,3-dimethylpentane, 2,2,3,3-tetramethylpentane, 2,2,4,4-tetramethylpentane, and 3,3-diethylpentane from 10 to about 400 K. Molar heat capacity at saturation pressure of the condensed phases, transition and melting temperatures, and enthalpies of transition and fusion were measured by adiabatic calorimetry. From the results, the thermodynamic quantities {Hs(T) − Ho(0)}, Ss, and Cs were derived and tabulated over the experimental temperature ranges of the crystalline and liquid states of each substance, and except for 2,3-dimethylpentane the standard entropies in the perfect gas state at 298.15 K were determined with the aid of literature data for vapor pressure and enthalpy of vaporization. Because, 2,3-dimethylpentane could not be crystallized, its thermodynamic properties are reported only for the glass and liquid states.

The low-temperature thermal properties of trimethylamineborane and triethylamineborane were determined by adiabatic calorimetry over the range 12 to 390 K and 12 to 310 K, respectively. The quantities measured include the heat capacity of the condensed phases, enthalpies of transition, transition temperatures, enthalpies of fusion, and triple-point temperatures. The results were used to calculate the following thermodynamic functions at selected temperatures for the solid and liquid phases: (G s − H 0 o ) T , (H s − H 0 o ) T , Hs − H0o, Ss, and Cs. Third law entropies and Gibbs energies of formation in the ideal gas state at 298.15 K for both compounds were computed from the results together with vapor pressures and enthalpies of formation from the literature.

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.