Thermodynamics Research Center / ThermoML | Thermochimica Acta

Low-temperature Heat Capacities and Thermochemistry on the Complex of Erbium Perchlorate with L-alpha-Glutamic Acid [Er2(L-Glu)2(H2O)8](ClO4)4*3H2O(s)

Di, Y.-Y.[You-Ying], Zhang, J.[Jian], Tan, Z.-C.[Zhi-Cheng]
Thermochim. Acta 2007, 463, 1-2, 10-12
ABSTRACT
A coordination compound of erbium perchlorate with l- -glutamic acid, [Er2(l-Glu)2(H2O)6](ClO4)4*6H2O(s), was synthesized. By chemical analysis, elemental analysis, FTIR, TG/DTG and comparison with relevant literature, its chemical composition and structure were established. The purity was found to be greater than 99.0%, without melting point. Low-temperature heat capacities were measured by a precision automated adiabatic calorimeter from 78 to 318 K. An endothermic peak in the heat-capacity curve was observed over the temperature region of 290-316 K, which was ascribed to a solid-to-solid phase transition. The temperature Ttrans, the enthalpy transHm and the entropy transSm of the phase transition for the compound were determined to be: 308.73+-0.45 K, 10.49+-0.05 kJ mol-1 and 33.9+-0.2 JK-1 mol-1. Polynomial equation of heat capacities as a function of the temperature in the region of 78-290K was fitted by the least square method.
Compounds
# Formula Name
1 C10H42Cl4Er2N2O36 erbium (II) perchlorate, L-glutamic acid complex, hydrate
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Triple point temperature, K ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Gas
  • Adiabatic calorimetry
  • 1
  • POMD
  • 1
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal 2
  • Crystal 2
  • Crystal 1
  • Gas
  • Adiabatic calorimetry
  • 1
  • POMD
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal 2
  • Temperature, K; Crystal 2
  • Pressure, kPa; Crystal 2
  • Crystal 2
  • Small (less than 1 g) adiabatic calorimetry
  • 83
  • POMD
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal 1
  • Temperature, K; Crystal 1
  • Pressure, kPa; Crystal 1
  • Crystal 1
  • Small (less than 1 g) adiabatic calorimetry
  • 6