| 王 凯,高肖汉,吕雪川,谭志诚,曹慧.化学通报,2016,79(2):141-146. |
| 稀土-天冬氨酸-咪唑配合物Sm2(Asp)2(Im)6(ClO4)6.6H2O的特殊低温相变和热力学性质 |
| Special phase transition under low temperature and thermodynamic properties of rare earth complex Sm2(Asp)2(Im)6(ClO4)6.6H2O |
| 投稿时间：2015-06-30 修订日期：2015-08-24 |
| DOI： |
| 中文关键词: 稀土配合物 固-固相转变 热稳定性 绝热量热法 热容 热力学函数 |
| 英文关键词:Rare earth complexes Solid-solid Phase transition Thermal stability Adiabatic calorimetry Heat capacity Thermodynamic function |
| 基金项目:国家自然科学青年基金资助项目(21103078,21003069) |
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| 中文摘要: |
| 合成了稀土钐配合物Sm2(Asp)2(Im)6(ClO4)6.6H2O。 (Asp, 天冬氨酸; Im, 咪唑),测定了该配合物晶体80–385 K温度区域的等压摩尔热容(Cp,m), 低温区间的绝热量热和差示扫描量热 (DSC)均发现配合物在220 K和 245 K附近存在固-固相转变, 推测其机理可能是配合物中高氯酸根离子重取向运动不同阶段所造成,根据实验热容数据和热力学公式, 计算出配合物80–385 K温度区域内相对于298.15 K 的标准热力学函数 [HT–H298.15]和[ST–S298.15], 根据热容测定数据计算出该相变的焓变和熵变。用热重法(TG)检测了配合物的热稳定性并推测其热分解机理。这两个低温区相变过程的发现,使开发此类配合物作为新低温相变材料成为可能。 |
| 英文摘要: |
| A ternary complex of rare earth ion, Sm2(Asp)2(Im)6(ClO4)6.6H2O, was synthesized and the thermodynamic properties of the complex were studied. Molar heat capacities at constant pressure (Cp,m) of the complex were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 80 to 390 K, and the thermodynamic functions (HT–H298.15 and ST–S298.15) were derived from the heat capacity data with temperature interval of 5 K. The phase transitions of the new complex around 220 K and 245 K were discovered both by adiabatic calorimetry and differential scanning calorimetry (DSC). The thermodynamic data of the phase transitions were calculated and the mechanism of transitions was deduced to be the reorientational process of perchlorate ions in the complex. Thermal stability of the complex was tested by thermogravimetric (TG) technique and a possible mechanism for the decomposition was suggested. |
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