Low-temperature Heat Capacities and Thermodynamic Properties of Solid State Coordination Compound Zn(nicotinate)_2·H_2O(s)  

作　　者：CHEN Jing-tao DI You-ying DAN Wen-yan HONG Yuan-ping YANG Wei-wei KONG Yu-xia HE Dong-hua TAN Zhi-cheng 

机构地区：[1]College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, P. R. China [2]Department of Chemistry, Shaanxi Educational College, Xi ＇an 710061, P. R. China

出　　处：《Chemical Research in Chinese Universities》2009年第4期526-531,共6页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China(No.20673050);Key Project of Science Foundation from Shaanxi Educational College of China(No.08KJ017)

摘　　要：A novel compound-monohydrated zinc nicotinate was prepared via room temperature solid phase synthesis and ball grinding.FTIR,chemical and elemental analyses and X-ray powder diffraction technique were applied to characterizing the structure and composition of the complex.Low-temperature heat capacities of the solid coordination compound were measured by a precision automated adiabatic calorimeter over a temperature range from 77 to 400 K.A solid-solid phase transition process occurred in a temperature range of 321―342 K inferred according to the heat capacity curve,and the peak temperature,molar enthalpy and entropy of the phase transition of monohydrated zinc nicotinate were determined to be Ttrs=（340.584±0.829） K,ΔtrsHm=（12.682±0.041） kJ/mol and ΔtrsSm=（37.235±0.101） KJ/mol）.The experimental values of the molar heat capacities in the temperature regions of 77―321 K and 342―400 K were,respectively,fitted to two polynomial equations.In addition,the polynomial fitted values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were calculated and tabulated at intervals of 5 K.A novel compound-monohydrated zinc nicotinate was prepared via room temperature solid phase synthesis and ball grinding.FTIR,chemical and elemental analyses and X-ray powder diffraction technique were applied to characterizing the structure and composition of the complex.Low-temperature heat capacities of the solid coordination compound were measured by a precision automated adiabatic calorimeter over a temperature range from 77 to 400 K.A solid-solid phase transition process occurred in a temperature range of 321―342 K inferred according to the heat capacity curve,and the peak temperature,molar enthalpy and entropy of the phase transition of monohydrated zinc nicotinate were determined to be Ttrs=（340.584±0.829） K,ΔtrsHm=（12.682±0.041） kJ/mol and ΔtrsSm=（37.235±0.101） KJ/mol）.The experimental values of the molar heat capacities in the temperature regions of 77―321 K and 342―400 K were,respectively,fitted to two polynomial equations.In addition,the polynomial fitted values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were calculated and tabulated at intervals of 5 K.

关 键 词：Zinc nicotinate Adiabatic calorimeter Heat capacity Phase transition Thermodynamic function 

分 类 号：O642.1[理学—物理化学] O614.113[理学—化学]