| Abstract: A ternary solid complex Lu(Et2dtc)3(phen) has been obtained from the reaction of hydrated lutetium chloride with sodium diethyldithiocarbamate
(NaEt2dtc), and 1,10-phenanthroline (o-phen·H2O) in absolute ethanol. IR spectrum of the complex indicates that
Lu3+ binds with sulfur atom in the Na(Et2dtc)3 and nitrogen atom in the o-phen. The enthalpy change of liquid-phase reaction of formation of the complex,
ΔrHmӨ (l), was determined to be (-32.821 ± 0.147 ) kJ·mol-1 at 298.15 K by an RD-496 Ⅲ type heat conduction microcalormeter. The enthalpy change of the solid-phase reaction of formation of the complex,
ΔrHmӨ (s), was calculated to be (104.160 ± 0.168) kJ ·
mol-1 on the basis of an appropriate thermochemistry cycle. The thermodynamics of liquid-phase reaction of formation of the complex was investigated by changing the temperature of liquid-phase reaction. Fundamental parameters, such as the activation enthalpy (ΔH≠Ө), the activation entropy (ΔS≠Ө), the activation free energy (ΔG≠Ө), the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A) and the reaction order (n), were obtained by combination the reaction thermodynamic and kinetic equations with the data of thermokinetic experiments. The molar heat capacity of the complex,
cm, was determined to be (82.23 ± 1.47) J·mol-1·K-1 by the same microcalormeter. The constant-volume combustion energy of the complex, ΔcU, was determined as (-17 898.228 ± 8.59) kJ·mol-1 by an RBC-Ⅱtype rotating-bomb calorimeter at 298.15 K. Its standard enthalpy of combustion,
ΔcHmӨ, and standard enthalpy of formation, ΔfHmӨ, were calculated to be (-17 917.43 ± 8.11) kJ·mol-1 and (-859.95 ±10.12) kJ·mol-1, respectively. |
