Heat Capacities and Thermodynamic Functions of Propanoylferrocene and Propylferrocene

Abstract

The heat capacities of propanoylferrocene (POF), C 5 H 5 FeC 5 H 4 COC 2 H 5 , and propylferrocene (PF), C 5 H 5 FeC 5 -H 4 C 3 H 7 -n, were measured by vacuum adiabatic calorimetry in the temperature ranges from (10 and 7) K to 372 K. The temperatures and enthalpies of the phase transitions and the purity of the samples have been determined. The solid phase transition of PF was studied by single-crystal crystallography in the temperature range from (150 to 200) K. The thermodynamic functions (absolute entropies, changes of the enthalpy, and Gibbs energy) of POF and PF were calculated for the solid and liquid phases of the temperature intervals studied. The ideal gas thermodynamic functions were derived at T ) 298.15 K using the data on saturated vapor pressure and the enthalpies and entropies of vaporization. A reliability of the ideal gas thermodynamic functions was corroborated by the additive calculation method. A mutual congruence of the absolute entropies of alkylferrocenes and acylferrocenes studied in this work and available in the literature were critically analyzed.