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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.

Heat capacity and enthalpy of transition were measured for phenanthrene, acenaphthene, fluorene, 1,2′-dinaphthylmethane, 1,8-,2,6-, and 2,7-dimethylnaphthalene from 10 to about 440 K in order to provide experimental data for deriving the following thermodynamic quantities over a range of temperature of the condensed phases and the perfect gas state: { H s ( T ) − H 0 (0)}, { S s ( T ) − S (0)}, C s , { H 0 ( T ) − H 0 (0)}, S o , ΔH f o , ΔS f o , ΔG f o , and log 10 K f o . Experimental values for the condensed states were converted to gaseous-state values with the aid of enthalpies of vaporization derived from vapor pressures and the Clapeyron equation. Linear relations of ΔG f o against T were used to extrapolate to standard values at 298.15 K.

Condensed-phase heat capacities and enthalpies were determined at temperatures from 10 to near 400 K for 1,4-dimethylbenzene, 1,2-diphenylethane, and 2,3-dimethylnaphthalene, and were used to provide values of enthalpies, entropies, and heat capacities at vapor saturation. Enthalpies and entropies for the ideal-gas state were determined at selected temperatures with available vapor pressures and enthalpies of vaporization. The enthalpies, entropies, and Gibbs energies of formation, also at selected temperatures, were derived for the ideal-gas state with available enthalpies of combustion.

Low-temperature calorimetric measurements were obtained on the condensed phases three alkanediamines, ethylenediamine, (dl)-1,2-propanediamine, and 2-methyl-1,2-propanediamine, as a basis for deriving their heat capacities, Cs, entropies, Ss, thermodynamic functions, −“Gs(T) − Ho(0)’T, “Hs(T) − Ho(0)’T, and Hs(T) − Ho(0), and the enthalpies, entropies, and temperatures of phase transitions. Vapor-pressure measurements were carried out on the above alkanediamines and (dl)-1,2-butanediamine as a means for transforming the condensed-state thermodynamic properties to the perfectgas state at 1 atm. Standard values at 298.15 K were calculated for the enthalpy, Gibbs energy, and equilibrium constant of formation.

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.

Low-temperature calorimetric studies were made on pure samples of 3-methyl-1-butanethiol (12 to 370 K), 3-methyl-2-butanethiol (12 to 370 K), 2-methylthiacyclopentane (12 to 370 K), 3-methylthiacyclopentane (12 to 336 K), cyclopentyl-1-thiaethane (12 to 370 K), and phenyl-1-thiaethane (12 to 320 K). From the above measurements the following thermodynamic functions at selected temperatures were calculated for the condensed phases: −{G s (T) − H(0)} T , { H s ( T ) − H (0)}, S s ( T ), and C s . By use of accurate vapor pressuresfrom this laboratory, S o ( g , 298.15 K) was obtained for each compound. From previously published values of ΔH t o for all six compounds and the measured value of S o ( g , 298.15 K), ΔG f o , and log 10 K t o were calculated.

Condensed-phase heat capacities and enthalpies were determined at temperatures from near 10 to 400 K for N-methylpyrrole, 2,5-dimethylpyrrole, piperidine, 2-methylpiperidine, 4-methylpyridine, and N-methylcarbazole, and were used to provide the Gibbs energy, enthalpy, entropy, and heat capacity along the vapor-saturation line at temperatures from 0 to 400 K. The corresponding ideal-gas thermodynamic properties were derived using available vapor pressures and enthalpies of vaporization. The Gibbs energy, enthalpy, and entropy of formation were derived for the ideal gas at selected temperatures with available enthalpies of combustion.

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.

Experimental measurements were made of the low-temperature thermal properties of 2-methylheptane and 2-methyldecane from 12 to 360 K and 12 to 390 K, respectively. From these measured values and data from the literature the following chemical thermodynamic properties were calculated at selected temperatures for the condensed phases of 2-methylbutane, 2-methylpentane, 2-methylhexane, 2-methylheptane, and 2-methyldecane: Gibbs energy function, enthalpy function, enthalpy, entropy, and heat capacity. The entropies of 2-methylheptane and 2-methyldecane in the ideal gas state at 298.15 K were calculated and methylene entropy increments obtained for the 2-methylalkanes, C 5 to C 11 .

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.

Calorimetrically determined values of the enthalpy and entropy of pure cis - and trans -hexahydroindan were used to calculate the thermodynamic properties and isomerization equilibrium mole fractions of the isomers in liquid and vapor phases. Experimental results are presented for heat capacities of the condensed phases from 12 to 390 K, enthalpies and entropies of fusion and solid-solid transitions, triple-point temperatures, sample purities, vapor pressures from 0.3 to 2025 Torr, and derived thermodynamic functions {G s (T)−H o (0)} T , {H s (T)−H o (0)} T , { H s ( T )− H s (0)}, and S s ( T ) at selected temperatures in solid, liquid, and vapor phases. Calculated isomeric equilibrium mole fractions for the reaction: trans -hexahydroindan = cis -hexahydroindan, based on the calorimetric measurements, are compared with mole fractions observed in catalyzed reaction equilibrium studies.

The low-temperature thermal properties of hexafluorobenzene and 1,3-difluorobenzene were measured by adiabatic calorimetry from 13 to 342 K and 11 to 355 K, respectively. The properties measured were heat capacities of solid and liquid, enthalpies of fusion, triple point temperature, and purity, and, in addition, for 1,3-difluorobenzene, the enthalpy and temperature of a solid-solid transition. From these results the following chemical thermodynamic functions were calculated for the condensed phases at selected temperature: Gibbs energy function, enthalpy function, enthalpy, entropy, and heat capacity. For 1,3-difluorobenzene the entropies in the ideal gas state were calculated at several temperatures, a revised vibrational assignment was made from Raman and infrared frequencies reported in the literature, and the chemical thermodynamic functions in the ideal gas state were calculated from 0 to 1500 K. Values of the Gibbs energy of formation and logarithm of equilibrium constant of formation for 1,3-difluorobenzene were also computed for the range 0 to 1500 K.

Low-temperature calorimetric quantities were determined for acrylonitrile, 1-aminopropane, 2-aminopropane, and 2-methyl-2-aminopropane from 12 K to near their respective normal boiling temperatures. Values of 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 these data the thermodynamic quantities −{G s (T) − H o (0)} T , {H a (T) − H o (0)} T , {Ha(T) − Ho(0)}, Ss, and Cs were evaluated for the solid and liquid states. For acrylonitrile a revised vibrational assignment was made from Raman and infrared wavenumbers reported in the literature, and a table of thermodynamic functions for the ideal gas state from 0 to 1000 K was prepared. Values of the enthalpy, Gibbs energy, and logarithm of equilibrium constant of formation for acrylonitrile also were computed for the range 0 to 1000 K.

The low-temperature thermal properties of 3-methylpentane and 3-methylheptane were measured by adiabatic calorimetry from 10 to 330 K and 10 to 380K, respectively. Properties measured included the heat capacity of the condensed phases, enthalpy of fusion, triple point temperature, and purity of sample. The results were used to calculate the following thermodynamic functions at selected temperatures for the solid and liquid phases: − {Gs(T) − H°(0)}/T, {Hs(T) − H°(0)}/T, Hs(T) − H°(0), Ss, and Cs. The entropies in the ideal gas state at 298.15 K were computed, and methylene increments of 7.69 calth K−1 mol−1 for the liquid state and 9.23 calth K−1 mol−1 for the vapor state were derived. Crystallization of the 3-methylpentane sample was induced (apparently for the first time) by cooling the liquid through the liquid-to-glass transition temperature (about 77 K), followed by slow warming to temperatures between the transition and the triple point (110.25 K).

Condensed-phase heat capacities and enthalpies were determined at temperatures from 10 to near 400 K for 1,4-dimethylbenzene, 1,2-diphenylethane, and 2,3-dimethylnaphthalene, and were used to provide values of enthalpies, entropies, and heat capacities at vapor saturation. Enthalpies and entropies for the ideal-gas state were determined at selected temperatures with available vapor pressures and enthalpies of vaporization. The enthalpies, entropies, and Gibbs energies of formation, also at selected temperatures, were derived for the ideal-gas state with available enthalpies of combustion.

Condensed-phase heat capacities and enthalpies were determined at temperatures from near 10 to 400 K for N-methylpyrrole, 2,5-dimethylpyrrole, piperidine, 2-methylpiperidine, 4-methylpyridine, and N-methylcarbazole, and were used to provide the Gibbs energy, enthalpy, entropy, and heat capacity along the vapor-saturation line at temperatures from 0 to 400 K. The corresponding ideal-gas thermodynamic properties were derived using available vapor pressures and enthalpies of vaporization. The Gibbs energy, enthalpy, and entropy of formation were derived for the ideal gas at selected temperatures with available enthalpies of combustion.