【摘要】 合成了两种固态稀土丙氨酸配合物[Ho2（Ala）4（H2O）8]Cl6和[ErY（Ala）4（H2O）8]（ClO4）6（Ala为丙氨酸）,用量热和热分析方法研究了这两种配合物的热力学性质.用全自动高精密绝热量热计测定了在78-377K温区内的低温热容.对于[Ho2（Ala）4（H2O）8]Cl6,在214-255K温区内发现一固-固相变,其相变温度为235.09K.对于[ErY（Ala）4（H2O）8]（ClO4）6,在99-121K温区内也发现一固-固相变,其相变温度为115.78K.[Ho2（Ala）4（H2O）8]Cl6固-固相变焓为3.02kJ·mol-1,相变熵为12.83J·K-1·mol-1;[ErY（Ala）4（H2O）8]（ClO4）6固-固相变焓为1.96kJ·mol-1,相变熵为16.90J·K-1·mol-1.同时,用TG技术在40-800℃温区研究了两配合物的热稳定性.由TG/DTG曲线分析可知,[Ho2（Ala）4（H2O）8]Cl6从80℃到479℃热分解分两步完成,[ErY（Ala）4（H2O）8]（ClO4）6从120℃到430℃热分解分三步完成.更多还原

【Abstract】 Two solid complexes of rare-earth compounds with alanine, [Ho2(Ala)4(H2O)8] Cl6, and [ErY(Ala)4 (H2O)8] (ClO4)6 (Ala = alanine) were synthesized, and a calorimetric study and thermal analysis for the two complexes were performed through adiabatic calorimetry and thermogravimetry. The low-temperature heat capacities of [Ho2(Ala)4 (H2O8]Cl6 and [ErY(Ala)4(H2O)8] (ClO4)6, were measured with an automated adiabatic precision calorimeter over the temperature range from 78 to 377 K. Solid-solid phase transitions were found between 214 K and 255 K with a peak temperature of 235. 09 K for [Ho2(Ala)4(H2O)8]Cl6, between 99 K and 121 K with a peak temperature of 115. 78 K for [ErY(Ala)4(H2O)8] (ClO4)6. The enthalpies and entropies of the phase transitions were determined to be 3. 02 kJ . mol-1, 12.83 J .K-1.mor-1 for [Ho2(Ala)4(H2O)8]Cl6; 1. 96 kJ. mol-1, 16.90 J. K-1.mor-1 for [ErY(Ala)4 (H2O)8] (C1O4)6, respectively. Thermal decomposition of the two complexes were investigated in the temperature range of 40 ~800℃ by using the thermogravimetric and differential thermogravimetric (TG/DTG ) analysis techniques. The TG/DTG curves showed that the decomposition started from 80℃ and ended at 479℃, completed in two steps for [Ho2(Ala)4(H2O)8]Cl6, and started from 120℃ and ended at 430 C, completed in three steps for [ErY(Ala)4(H2O)8] (ClO4)6, respectively. The possible mechanisms of the thermal decompositions were elucidated.更多还原