177723-35-2Relevant academic research and scientific papers
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.
The dehydration schemes of rare-earth chlorides
Hong, Vu Van,Sundstroem, Johan
, p. 37 - 43 (2008/10/09)
The dehydration schemes of LaCl3·7H2O, CeCl3·7H2O, PrCl3·7H2O, PrCl3·7H2O, EuCl3·6H2O, GdCl3·OH2O, HoCl3·6H2O, ErCl3·OH2O, TmCl3·6H2O, YbCl3·OH2O and YCl3·6H2O have been investigated by the isothermal fluidizedbed technique. This technique is based on the fact that reactions proceed at a close approach to equilibrium and thus give rise to constant reaction rate regimes at constant gas flow and temperature in the bed. By injecting a small portion of HCl(g) (～1%) into the gas stream, hydrolysis is avoided, and dehydration to the monohydrate is recorded by both thermal analysis of the preheated inlet gas and chemical analysis of samples taken from the bed. Based on the present results, together with previous results on NdCl3·OH2O, TbCl3·6H2O and DyCl3·6H2O, dehydration schemes of all rare-earth chlorides except LuCl3 and ScCl3 are suggested.
