Thermochemistry of the Ternary Complex Nd（Et2dtc）3（phen）

Introduction A series of lanthanide sulfide complexes have beenlargely used for ceramics and thin film materials1 andthese complexes could be prepared from the precursorswhich are the compounds containing lanthanide-sulfurbonds.2-4 For instance, the compounds synthesized with(alkyl)2dtc]-, phen?H2O and lanthanide salts were usedas the volatile precursors for preparing lanthanide sul-fide, its friction properties in lubricant was investigatedin literature 5 and the preparation and propertie…

Thermochemistry of the Ternary Complex Nd(Et_2dtc)_3(phen)

The ternary solid complex has been synthesized with sodium diethyldithiocarbamate (NaEt₂dtc·3H₂O), 1,10‐phenanthroline (o‐phen·H₂O) and hydrated neodymium chloride in absolute ethanol. The title complex was identified as the general formula of Nd(Et₂dtc)₃(phen) by chemical and elemental analyses. IR spectrum of the complex showed that the Nd³⁺ coordinated with six sulfur atoms of three NaEt₂dtc and two nitrogen atoms of o‐phen. It was assumed that the coordination number of Nd³⁺ is eight. The enthalpy change of liquid‐phase reaction of formation, Δ_rH (1), was determined as (‐12.274±0.050) kJ·mol^?1 at 298.15 K by a microcalorimeter, the enthalpy change of the solid‐phase reaction of formation, Δ_rH (s), was calculated as (149.069±0.314) kJ·mol^?1 on the basis of a thermochemical cycle. The thermodynamics of reaction of formation was studied by changing the temperature of liquid‐phase reaction. The constant‐volume combustion energy of the complex, Δ_cU, was determined as (‐18674.22±8.33) kI·mol^?1 by a precise rotating‐bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, Δ_cH, and standard enthalpy of formation, Δ_fH, were calculated as (‐18693.43 ± 8.33) kJ·mol^?1 and (‐47.03 ± 9.17) kJ·mol^?1, respectively.