114363-89-2Relevant articles and documents
Solution enthalpies of hydrates LnCl3·xH2O (Ln=Ce-Lu)
Seifert,Funke
, p. 1 - 7 (2008/10/09)
Trichlorides of the lanthanide elements Ln=Ce-Lu form: (a) isotypic hexahydrates LnCl3·6H2O with a coordination number (CN) 8 for the Ln3+ ions. (b) Two isotypic groups of trihydrates LnCl3·3H2O, in the first group Ln=Ce-Dy the CN is 8; the structure of the second group Ln=Er-Lu is unknown. With Ho no trihydrate exists; a dihydrate is formed. (c) Two isotypic groups of monohydrates LnCl3·H2O with unknown structure - Ln=Ce-Dy and Ln=Ho-Lu. For all compounds and for anhydrous chlorides LnCl3 solution enthalpies were measured with an isoperibolic calorimeter. The ΔsolH0 values do not depend only on the difference (lattice enthalpies/hydration enthalpies), but also on the state in solution. According to Spedding the CN of the Ln3+ ions against water changes from 9 to 8 between Nd and Sm, causing minima in the series of solution enthalpies. Dihydrates LnCl3·2H2O are found for Ln=Ce, Pr, Nd, Sm and presumably for Eu and Gd. They are not yet well characterised.
Ternary chlorides in the systems CsCl/ErCl3 and RbCl/ErCl3
Buechel, Dorothea,Krok-Kowalski, Jozef,Seifert, Hans-Joachim
, p. 297 - 304 (2008/10/09)
The phase diagram of the system RbCl/ErCl3 was investigated by means of DTA and the system CsCl/ErCl3 was re-investigated. The existence of the caesium compounds Cs3ErCl6 (dimorphic), Cs2ErCl5, Cs3Er2Cl7 and CsEr2Cl7 was confirmed. In the system RbCl/ErCl3, there are two dimorphic, congruently melting compounds, Rb3ErCl6 and RbEr2Cl7. The incongruently melting compound Rb2ErCl5 (Cs2DyCl5 structure) is stable at temperatures higher than 348°C. The thermodynamic stabilities of the compounds were determined by solution calorimetry and e.m.f. measurements in a galvanic chlorine cell for solid electrolytes.