Heat Capacities and Thermodynamic Properties of Lanthanum/Holmium Perchlorate Complexes with Glycine  

作　　者：刘北平 谭志诚 余华光 陈贞干 孙立贤 兰孝征 刘平 邸友莹 

机构地区：[1]Thermochemistry Laboratory,Dalian Institute of Chemical Physics,Chinese Academy of Sciences [2]Department of Chemistry, Changde Normal College, Changde, Hunan 415000, China [3]Department of Chemistry,Changde Normal College

出　　处：《Chinese Journal of Chemistry》2003年第4期396-399,共4页中国化学（英文版）

基　　金：theNationalNaturalScienceFoundationofChina (No .2 0 0 73 0 47);theNaturalScienceFoundationofHunanProvince(No .0 0JJY2 0 115 )

摘　　要：The heat capacities of the two complexes, [La 2(Gly) 6(H 2O) 4]^(ClO 4) 6 and [Ho 2(Gly) 6(H 2O) 4](ClO 4) 6·2H 2O (Gly=glycine), were measured by adiabatic calorimetry in the temperature range from 78 to 375 K. A solid solid phase transition was found between 322 87 and 342 29 K for [Ho 2(Gly) 6(H 2O) 4](ClO 4) 6·2H 2O, and the peak temperature, the enthalpy and the entropy of the transition were obtained to be 330 94 K, 11 65 kJ·mol -1 and 35 20 J·K -1 ·mol -1 , respectively. No indication of any phase transition or thermal anomaly was observed for [La 2(Gly) 6(H 2O) 4]^(ClO 4) 6. Thermal stabilities of the two complexes were investigated by thermogravimetry in the temperature range of 40—800 ℃. The possible mechanisms for the thermal decompositions were proposed according to the TG and DTG curves.The heat capacities of the two complexes, [La 2(Gly) 6(H 2O) 4]^(ClO 4) 6 and [Ho 2(Gly) 6(H 2O) 4](ClO 4) 6·2H 2O (Gly=glycine), were measured by adiabatic calorimetry in the temperature range from 78 to 375 K. A solid solid phase transition was found between 322 87 and 342 29 K for [Ho 2(Gly) 6(H 2O) 4](ClO 4) 6·2H 2O, and the peak temperature, the enthalpy and the entropy of the transition were obtained to be 330 94 K, 11 65 kJ·mol -1 and 35 20 J·K -1 ·mol -1 , respectively. No indication of any phase transition or thermal anomaly was observed for [La 2(Gly) 6(H 2O) 4]^(ClO 4) 6. Thermal stabilities of the two complexes were investigated by thermogravimetry in the temperature range of 40—800 ℃. The possible mechanisms for the thermal decompositions were proposed according to the TG and DTG curves.

关 键 词：lanthanum/holmium perchlorate  glycine complex adiabatic calorimetry heat capacity THERMOGRAVIMETRY thermal decomposition 

分 类 号：O621[理学—有机化学]