title: Thermodynamics of the hydration equilibrium derived from the luminescence spectra of the solid state for the case of the Eu-EDTA system.
abstract: The luminescence properties of two compounds, [C(NH2)3][Eu(EDTA)(H2O)3] (I) and [C(NH2)3]2[Yb0.97Eu0.03(EDTA)(H2O)2]ClO4·6H2O (II), were determined. The weighted sum of luminescence spectra of I and II was used to reproduce the spectra of the Eu-EDTA system in aqueous solution in the temperature range 276-363 K. By implementing this method it was possible to determine the thermodynamic functions (ΔH = 18113 ± 506 J mole(-1) and ΔS = 62.5 ± 4.9 J mole(-1) K(-1)) of the reaction [Eu(EDTA)(H2O)3](-)⇆ [Eu(EDTA)(H2O)2](-) + H2O, which is difficult using other methods.
authors.affiliation: University of Wrocław, Faculty of Chemistry, F. Joliot-Curie 14, 50-383 Wrocław, Poland. rafal.janicki@chem.uni.wroc.pl.
authors.forename: R
authors.initials: R
authors.lastname: Janicki
authors.forename: A
authors.initials: A
authors.lastname: Mondry
mesh_terms: D004492:Edetic Acid / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D049449:Luminescence; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D005063:Europium; D004492:Edetic Acid