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

A ternary solid complex Eu(Et(2)dtc)(3)(phen) has been obtained from the reaction of sodium diethyldithiocarbamate (NaEt(2)dtc), 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, Delta H-t(m)theta (1), 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, Delta H-t(m)theta (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 (Delta H-not equal(0)), the activation entropy (Delta S-not equal(0)), the activation free energy (Delta G(not equal)(0)) and the enthalpy (Delta H-r(not equal)0), were obtained combination the reaction thermodynamic and kinetic equations with the data of thermokinetic experiments. The constant-volume combustion energy of the complex, Delta U-c, was determined as -(17410.63 +/- 8.95) kJ (.) mol(-1) by a RBC-Pi rotating-bomb calorimeter at T = 298.15 K. Its standard enthalpy of combustion, Delta H-c(m)0, and standard enthalpy of formation, Delta H-f(m)0, were calculated to be -(17429.84 +/- 8.95) kJ (.) mol(-1) and -(1231.76 +/- 9.92) kJ (.) mol(-1), respectively. (c) 2004 Elsevier Ltd. All rights reserved.