Thermodynamical Study on Rare Earth L-Isoleucine Chlorate Complexes [RE₂(lle)₄(H₂O)₈](ClO₄)₆ (RE = Nd, Er)

Abstract

Using perchloric acid, Nd2O3, Er2O3 and L-isoleucine (Ile) as raw materials, two crys-talline compounds of rare earth isoleucine chlorate, [Nd2(Ile)4(H2O)8](ClO4)6 and [Er2(Ile)4(H2O)8](ClO4)6, were synthesized. Their compositions were determined after chemical analysis, IR spectrum study, thermogravimetric (TG) and differential thermal analysis (DTA). By using the RD496-2000 microcalorimeter, the standard enthalpies of formation of the synthesized compounds were obtained according to a pre-designed thermal cycle. Four sets of TG data with different heating rates (2.5 K•min-1, 5 K•min-1, 10 K•min-1 and 15 K•min-1) were obtained. After the exploration of the kinetic data in the non-isothermal thermal decomposition process, the activation energy E, the logarithm of the pre-exponential factor lnA, the reaction order n, and the dynamical equation of the water loss step were derived. Ozawa method was also used to test the obtained dy-namical data.