Thermochemical Study of Coordination of Holmium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate

摘要

The complex of holmium chloride hydrate with diethylammonium diethyldithiocarbamate(D-DDC) was synthesized via mixing their solutions in absolute alcohol under a dry N 2 atmosphere. The elemental and chemical analyses show that the complex has the general formula Et 2NH 2[Ho(S 2CNEt 2) 4]. It was also characterized by IR spectroscopy. The enthalpies of the dissolution of holmium chloride hydrate and D-DDC in absolute alcohol at 298.15 K, and the enthalpy changes of liquid-phase reactions of the formation of Et 2NH 2[Ho(S 2CNEt 2) 4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters(the activation enthalpy, the activation entropy and the activation free energy), the rate constant and three kinetic parameters(the apparent activation energy, the pre-exponential constant and the reaction order) of the liquid-phase reaction of the complex formation were obtained. The enthalpy change of the solid-phase complex formation reaction at 298.15 K was calculated by means of a thermochemical cycle.