INTERACTIONS BETWEEN LANTHANIDE CATIONS AND NITRATE ANIONS IN WATER PART 2 MICROCALORIMETRIC DETERMINATION OF THE GIBBS ENERGIES, ENTHALPIES AND ENTROPIES OF COMPLEXATION OF Y3+ AND TRIVALENT LANTHANIDE CATIONS
C. Bonal et al., INTERACTIONS BETWEEN LANTHANIDE CATIONS AND NITRATE ANIONS IN WATER PART 2 MICROCALORIMETRIC DETERMINATION OF THE GIBBS ENERGIES, ENTHALPIES AND ENTROPIES OF COMPLEXATION OF Y3+ AND TRIVALENT LANTHANIDE CATIONS, Journal of the Chemical Society. Faraday transactions, 94(10), 1998, pp. 1431-1436
Citations number
48
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Microcalorimetry is applied to the study of the very weak complexation
of Y3+ and trivalent lanthanide cations (La3+, Ce3+ , Pr3+, Gd3+, Tb3
+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+ and Lu3+) by nitrate anion in water at
298.15 K. For each cation, both the apparent association constant and
enthalpy of reaction at an ionic strength of 2.0 mol kg(-1) are extra
cted from the calorimetric data. The Gibbs energies, enthalpies and en
tropies of complexation of these lanthanide cations, to which are adde
d the values previously found for Nd3+, Sm3+ and Eu3+, are extrapolate
d to infinite dilution using the Fitter interaction model and the ioni
c strength effect previously observed with neodymium. An attempt is al
so made to extract the enthalpies of complexation from the available h
eats of dilution by comparing the nitrate and perchlorate heat data; t
he results agree quite well with the values found by microcalorimetry.
The trends in the thermodynamic properties of association with the ca
tion radius are examined. Some of the properties show breakpoints that
delimit four subfamilies, a pattern that may possibly be attributed t
o a tetrad effect.