稀土脯氨酸高氯酸盐配合物[RE_2(Pro)_6(H_2O)_4](ClO_4)_6(RE=Pr,Er)的低温热容及热力学性质

Low Temperature Heat Capacities and Thermodynamic Property of Rare Earth Complexes with Proline Perchlorate [RE_2(Pro)_6(H_2O)_4](ClO_4)_6(RE=Pr,Er)

合成了两种纯度分别是 99.2 4%和 98.2 0 %的单晶稀土脯氨酸高氯酸盐配合物 [Pr2 (Pro) 6 (H2 O) 4](Cl O4) 6 和 [Er2 (Pro) 6 (H2 O) 4](Cl O4) 6 ,对该配合物进行了热容、热重、差热和标准燃烧热等测定。在 78～ 370 K温度区 ,用高精密全自动绝热量热仪测定了热容值 ,计算机拟合得其热容对温度的多项式方程分别为 :Cp=140 7.0 8+75 1.6 7X +170 .17X2 +89.5 9X3- 76 .11X4和 Cp=1317.99+6 33.0 5 X +16 3.82 X2 +15 0 .2 3X3- 86 .2 1X4,[Er2(Pro) 6 (H2 O) 4](Cl O4) 6 的 Cp- T曲线有一熔化峰 ,计算熔点为 35 5 .5 5 K,熔化熵为 6 9.5 42 J/(K m ol) ,熔化焓为2 472 5 .81J/m ol。 TG、DTA技术研究了其热分解过程 ,初步分析了配合物的分解机理。燃烧热实验给出了它们的标准燃烧热分别为 1772 0 .41k J/mol和 1810 1.6 5 k J/m

Two single crystal rare earth complexes with proline perchlorate [Pr 2(Pro) 6(H 2O) 4](ClO 4) 6,[Er 2(Pro) 6(H 2O) 4](ClO 4) 6,have been synthesized.The heat capacities,standard combustion heats and TG,DTA curves have been measured.Heat capacities of [RE 2(Pro) 6(H 2O) 4](ClO 4) 6(RE=Pr,Er)were determined with a high precision automatic adiabatic calorimeter over the temperature range from 78 to 370K.The heat capacity curves of two samples are fitted by computer:C p=1407.08+751.67X+170.17X 2+89.59X 3-76.11X 4 and C p=1317.99+633.05X+163.82X 2+150.23X 3-86.21X 4.There is a peak temperature in the C p-T curve of [Er 2(Pro) 6(H 2O) 4](ClO 4) 6,the melting point,the melting entropy and enthalpy are 355.55K,69.542J/K mol and 24725.81J/mol by calculation,respectively.The experiments of TG and DTA of the samples have been made,while their possible thermal decomposition mechanisms have been proposed.Their combustion heat values have been determined to be 17720.41kJ/mol and 18101.65kJ/mol,respectively.