Thermochemistry of the ternary complex Eu(Et2dtc)3(phen)

A ternary solid complex Eu(Et2dtc)3(phen) has been obtained the from reaction of sodium diethyldithiocarbamate (NaEt2dtc), 1,10-phenanthroline (phen) and hydrated europium chloride in absolute ethanol. The title complex was described by chemical and elemental analyses, TG-GTG and IR spectrum. The enthalpy change of liquid-phase reaction of formation of the complex, ΔrHmθ (l), was determined as−(13.481 ± 0.0314) kJ · mol−1 at T = 298.15 K by a RD-496 III heat conduction microcalorimeter. The enthalpy change of the solid-phase reaction of formation of the complex, ΔrHmθ (s), was calculated as (152.317 ± 0.542) kJ · mol−1 on the basis of a designed thermochemical cycle and other auxiliary thermodynamic qualities. The thermodynamics of reaction of formation of the complex was investigated by changing the temperature of liquid-phase reaction. Fundamental parameters, the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A), the reaction order (n), the activation enthalpy (ΔH≠θ), the activation entropy (ΔS≠θ), the activation free energy (ΔG≠θ) and the enthalpy (ΔrH≠θ), were obtained combination the reaction thermodynamic and kinetic equations with the data of thermokinetic experiments. The constant-volume combustion energy of the complex, ΔcU, was determined as −(17410.63 ± 8.95) kJ · mol−1by a RBC-Π rotating-bomb calorimeter at T = 298.15 K. Its standard enthalpy of combustion, ΔcHmθ, and standard enthalpy of formation, ΔfHmθ, were calculated to be −(17429.84 ± 8.95) kJ · mol−1 and −(1231.76 ± 9.92) kJ · mol−1, respectively.