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合成了一种稀土高氯酸盐-谷氨酸配合物.经TG/DTG、化学和元素分析、FTIR及与相关文献对比,确定其组成为[Pr2(L-α-Glu)2(ClO4)(H2O)7](ClO4)3?4H2O,纯度为99.0%以上.利用显微熔点仪分析发现其没有熔点.在78～370K温区,用精密绝热量热仪测量其低温热容,在285～306K温区发现一明显吸热峰,归结为固-固相变过程.通过相变温区三次重复热容测量,得到相变温度Ttr、相变焓?trHm和相变熵?trSm分别为(297.158±0.280)K,(12.338±0.016)kJ?mol-1和(41.520±0.156)J?K-1?mol-1.用最小二乘法将非相变温区的热容对温度进行拟合,得到了热容随温度变化的两个多项式方程.用此方程进行数值积分,得到每隔5K的舒平热容值和相对于273.15K的热力学函数值.根据TG/DTG结果,推测了该配合物的热分解机理.依据Hess定律,选择1mol?dm-3盐酸为量热溶剂,利用等温环境溶解-反应量热计,测定了该配合物的标准摩尔生成焓为:?fHm=-(7223.1±2.4)kJimol-1.
A novel rare earth perchlorate-glutamate complex was synthesized and its composition was determined to be [Pr2 (L-α-Glu) 2 (ClO4)) by TG / DTG, chemical and elemental analysis, FTIR and related literature. (H2O) 7] (ClO4) 3 ~ 4H2O, the purity is above 99.0% .It has no melting point by means of micro melting point analysis.At the temperature range of 78 ~ 370K, its low temperature heat capacity is measured by precision adiabatic calorimeter, ~ 306K temperature region was found a significant endothermic peak, attributed to the solid-solid phase transformation process.Through the phase transition temperature measurement of three repeated heat capacity, the phase transition temperature Ttr, phase transition enthalpy? TrHm and phase transition entropy? TrSm were (297.158 ± 0.280) K, (12.338 ± 0.016) kJ? Mol-1 and (41.520 ± 0.156) J? K-1? Mol- 1. The heat capacity of non-phase- And got two polynomial equations of heat capacity with temperature.Using this equation for numerical integration, the heat capacity at 5K and the thermodynamic function value at 273.15K were obtained.According to the results of TG / DTG According to Hess’s law, 1 mol? Dm-3 hydrochloric acid was used as a caloric solvent, and the standard molar enthalpy of formation of the complex was determined by isothermal environment dissolution-reaction calorimeter: fHm = - (7 223.1 ± 2.4) kJimol-1.