摘要
利用精密绝热热量仪测定了配合化合物Zn(Met)_3(NO_3)_2·H_2O(s)(Met=L-α-蛋氨酸)在78-371 K温区的摩尔热容.通过热容曲线解析,得到了该配合物的起始脱水温度为T_D=325.10 K.将该温区的摩尔热容实验值用最小二乘法拟合得到了摩尔热容(C_p)对约化温度(T)的多项式方程,由此计算得到了配合物的舒平热容值和热力学函数值.基于设计的热化学循环,选择100 mL 2 mol·L^(-1)HCl溶液为量热溶剂,利用等温环境溶解-反应热量计,得到了298.15 K配合物的标准摩尔生成焓Δ_f H_m^0[Zn(Met)_3(NO_3)_2·H_2O,s]=-(1472.65±0.76)J·mol^(-1).
Low temperature heat capacities of the compound Zn(Met)3(NO3)2 .H2O(s) have been measured by a precision automated adiabatic calorimeter over the temperature range 78-371 K. The initial dehydration temperature of the coordination compound was determined to be TD=325,10 K by analysis of the heat-capacity curve. The experimental values of the molar heat capacities in the temperature region have been fitted to a polynomial equation of heat capacities with the reduced temperature (X), [X= f(T)], by the least squares method. Smoothed heat capacities and thermodynamic functions relative to the standard reference temperature 298.15 K of the compound were derived from the fitted polynomial equation and listed at 5 K internals. Using 100 mL of 2 mol. L-1 HCl(aq) as calorimetric solvent, with an isoperibol solution-reaction calorimeter, the standard molar enthalpy of formation of the compound was determined to be △fH0m[Zn(Met)3(NO3)2·H2O,s]=-(1472.6±0.76)J.mol-1 by a designed thermochemical cycle.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2013年第10期2129-2134,共6页
Acta Physico-Chimica Sinica
基金
the National Natural Science Foundation of China(21273171,21127004,21173168)
Scientific Research Program Funded by Shaanxi Provincial Education Department,China(11JK0578,11JS110)~~