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Low-temperature heat capacities of pyrimethanil laurate (C24H37N3O2) were precisely measured with an automated adiabatic calorimeter over the temperature range between T=78 K and T=340 K. The sample was observed to melt at (321.52±0.04) K. The molar enthalpy and entropy of fusion as well as the chemical purity of the compound were determined to be (67244±11) J·mol−1, (209.28±0.02) J·mol−1·K−1, (0.9943±0.0004) mass fraction, respectively. The extrapolated melting temperature for the absolutely pure compound obtained from fractional melting experiments was (322.264±0.006) K. [Copyright &y& Elsevier]

Pyrimethanil myristic salt was synthesized and its heat capacities were measured with an automated adiabatic calorimeter over the temperature range from T=(79 to 360) K.The melting point, molar enthalpy, ΔfusHm and entropy, ΔfusSm, of fusion of this compound were determined to be (321.84 ± 0.05) K, (56.53 ± 0.03) kJ · mol−1 and (175.64 ± 0.05) J · mol−1 · K−1, respectively. The purity of the compound was calculated to be 98.99 mol% by using the fractional melting technique. The thermodynamic functions relative to the reference temperature, T=298.15 K, were calculated based on the heat capacity measurements in the temperature ranges from T=(80 to 360) K. The TG-DTG results demonstrate that the mass loss of the sample takes place in one step with the maximum rate at T=500 K, which was caused by evaporation of the sample. [Copyright &y& Elsevier]

The molar heat capacities of 1-(2-hydroxy-3-chloropropyl)-2-methyl-5-nitroimidazole (Ornidazole) (C7H10ClN3O3) with purity of 99.72 mol% were measured with an adiabatic calorimeter in the temperature range between 79 and 380 K. The melting-point temperature, molar enthalpy, ΔfusHm, and entropy, ΔfusSm, of fusion of this compound were determined to be 358.59±0.04 K, 21.38±0.02 kJ mol−1 and 59.61±0.05 J K−1 mol−1, respectively, from fractional melting experiments. The thermodynamic function data relative to the reference temperature (298.15 K) were calculated based on the heat capacities measurements in the temperature range from 80 to 380 K. The thermal stability of the compound was further investigated by DSC and TG. From the DSC curve an intensive exothermic peak assigned to the thermal decomposition of the compound was observed in the range of 445–590 K with the peak temperature of 505 K. Subsequently, a slow exothermic effect appears when the temperature is higher than 590 K, which is probably due to the further decomposition of the compound. The TG curve indicates the mass loss of the sample starts at about 440 K, which corresponds to the decomposition of the sample. [Copyright &y& Elsevier]

Low-temperature heat capacities of the 9-fluorenemethanol (C14H12O) have been precisely measured with a small sample automatic adiabatic calorimeter over the temperature range between T=78 K and T=390 K. The solid–liquid phase transition of the compound has been observed to be Tfus=(376.567±0.012) K from the heat-capacity measurements. The molar enthalpy and entropy of the melting of the substance were determined to be ΔfusHm=(26.273±0.013) kJ · mol−1 and ΔfusSm=(69.770±0.035) J · K−1 · mol−1. The experimental values of molar heat capacities in solid and liquid regions have been fitted to two polynomial equations by the least squares method. The constant-volume energy and standard molar enthalpy of combustion of the compound have been determined, ΔcU(C14H12O, s)=−(7125.56 ± 4.62) kJ · mol−1 and ΔcHm∘(C14H12O, s)=−(7131.76 ± 4.62) kJ · mol−1, by means of a homemade precision oxygen-bomb combustion calorimeter at T=(298.15±0.001) K. The standard molar enthalpy of formation of the compound has been derived, ΔfHm∘(C14H12O,s)=−(92.36 ± 0.97) kJ · mol−1, from the standard molar enthalpy of combustion of the compound in combination with other auxiliary thermodynamic quantities through a Hess thermochemical cycle. [Copyright &y& Elsevier]