稀土脯氨酸配合物[RE2(L-Pro)6(H2O)4](ClO4)6的标准生成焓测定

合成了两种稀土高氯酸盐与L 脯氨酸配合物的晶体.经热重、差热、化学分析及对比有关文献,知其组成是Pr2(L Pro)6(H2O)4](ClO4)6和Er2(L Pro)6(H2O)4](ClO4)6,质量分数为99.24％和98.20％.选用RE(NO3)3•6H2O(RE=Pr,Er)、L Pro、NaClO4•H2O和NaNO3作辅助物,使用具有恒温环境的反应热量计,以2 mol•L－1 HCl作溶剂,分别测定了2RE(NO3)3•6H2O＋6L Pro＋6NaClO4•H2O]和{RE2(L PrO)6(H2O)4](ClO4)6＋6NaNO3}在298.15 K时的溶解热.设计一热化学循环求得化学反应的反应焓ΔrHm分别是：63.904 kJ•mol－1和91.017 kJ•mol－1,经计算得配合物RE2(L Pro)6(H2O)4](ClO4)6(s)在298.15 K时的标准生成焓ΔfHm(298.15 K)分别是－6 594.78 kJ•mol－1和－6 532.87 kJ•mol－1.

Determination of Standard Enthalpies of Formation of Rare Earth (RE = Pr, Er)with L-Proline [ RE2 (L-Pro)6 (H2O)4 ] (ClO4)6 Complexes

Crystals of two complex compounds of rare earth perchlorate with L proline,RE2(L Pro)6(H2O)4](ClO4)6(RE=Pr,Er),were synthesized.Their structures were characterized using TG,DTA,chemical analytic method and comparing with literatures,and the purity is determined as 99.24％ and 98.20％,respectively.For the calculation of chemical reaction heat,solution heat of the 2RE(NO3)3•6H2O＋6L Pro＋6NaClO4•H2O] and the {RE2(L Pro)6(H2O)4](ClO4)6＋6NaNO3} were firstly measured in 2 mol•L 1 HCl solvent with an isoperibel reaction calorimeter,respectively.The standard enthalpy of formation of the two crystals were calculated by chemical reaction heat and a designed thermochemical cycle at 298.15 K.The following reaction enthalpy and standard enthalpy of formation were obtained: 　　RE=Pr:ΔrHm=－63.904 kJ•mol－1;RE=Er:ΔrHm=－ 91.017 kJ•mol－1; 　　ΔfHm(Pr2(L Pro)6(H2O)4](ClO4)6,s,298.15 K)=－6 594.78 kJ•mol－1; 　　ΔfHm(Er2(L Pro)6(H2O)4](ClO4)6,s,298.15 K)=－6 532.87 kJ•mol－1.