Abstract: The ternary solid complex, Tb(Et2dtc)3(phen),has been synthesized with sodium diethyldithiocarbamate(NaEt2dtc), 1,10-phenanthroline(o-phen•H2O) and low hydrated terbium chloride in absolute ethanol. IR spectrum of the complex showed that the Tb3＋ coordinated with six sulfur atoms of three NaEt2dtc and two nitrogen atoms of phen. The enthalpies change of liquid-phase reaction of formation,ΔrHmθ(l),was determined as(－21.819±0.055) kJ•mol－1 at 298.15 K by a microcalorimeter, the enthalpies change of the solid-phase reaction of formation,ΔrHmθ(s), was calculated as(128.476±0.675) kJ•mol－1 on the basis of a thermochemical cycle. The thermodynamic of reaction of formation was studied by changing the temperature of liquid-phase reaction. The constant-volume combustion energy of the complex,ΔcU, was determined as(－17646.95±8.64) kJ•mol－1 by a precise rotating-bomb calorimeter at 298.15 K. Its standard enthalpies of combustion,ΔcHmθ, and standard enthalpies of formation,ΔfHmθ, were calculated as(－17666.16±8.64) kJ•mol－1 and (－1084.04±9.49) kJ•mol－1, respectively.

Key words: Tb(Et₂dtc)₃(phen), Microcalorimeter, 　Thermodynamics, Constant-volume combustion energy, Standard mole enthalpy of formation