二水合2-吡嗪羧酸锌(Zn(pyza)_2(H_2O)_2(s))的晶体结构和热化学性质  

Crystal structure and thermochemical properties of 2-pyrazine carboxylate zinc dihydrate(Zn(pyza)_2(H_2O)_2(s))

作　　者：王晓兰[1] 王建军[1] 陈经涛[1] 

机构地区：[1]陕西学前师范学院化学与化工系,陕西西安710061

出　　处：《陕西师范大学学报（自然科学版）》2015年第5期54-60,共7页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：陕西省教育厅科学研究计划(2013JK0663);陕西学前师范学院科研基金重点项目(2012KJ008)

摘　　要：以二次蒸馏水为溶剂,合成了二水合2-吡嗪羧酸锌（Zn（pyza）2（H2O）2（s））。利用X-射线单晶衍射法表征其晶体结构,应用TG/DSC热分析技术研究了该化合物的热分解特性,采用绝热量热计测量了该配合物在80~400K的低温热容。根据实验结果,通过最小二乘法拟合原理,得到了该配合物的摩尔热容随折合温度变化的公式,计算出该化合物的舒平热容和热力学函数数据。依据热化学循环原理,利用等温环境下的溶解-反应热量计,测定了所设计热化学反应的反应物和生成物在所选定溶剂中的溶解焓,通过计算得出该反应的反应焓数值为-（49.555±0.403）kJ/mol。利用Hess定律计算出2-吡嗪羧酸锌的标准摩尔生成焓为-（858.62±2.30）kJ/mol。利用紫外-可见光谱仪对反应物和产物溶解所得溶液分别进行测量,从而证实所设计热化学循环的可靠性。With twice-distilled water as the solvent,2-pyrazinyl acid dihydrate zinc（Zn（pyza）2（H2O）2（s））was synthesized,and its crystal structure was characterized bny X-ray diffraction method.By using TG/DSC technique,the behavior for the thermal decomposition of the compound were revealed.Using automatic adiabatic calorimeter,the complex at 80~400Kof the low-temperature heat capacity was measured.Based on the results,and the least squares fitting,the formula of complex the molar heat capacity versus the equivalent temperature was obtained,and the smoothed heat capacities of the compound and various thermodynamic function data were calculated.Based on thermochemical cycle principle,the use of dissolution-reaction calorimeter under isothermal environment,the designed heat chemical reaction enthalpy of the reactants and products dissolved in the selected were measured,solvents and the reaction enthalpy is-（49.555±0.403）kJ/mol.Using Hess′s law,the standard molar enthalpy of 2- pyridine triazine zinc carboxylate was-（858.62±2.30）kJ/mol.Using UV-visible spectrometer,the speatra of the reactants and products solution were measured.Based on the spectra results,the reliability of the designed thermochemical cycle is confirmed.

关 键 词：水合2-吡嗪羧酸锌 晶体结构 TG/DSC 低温热容 标准摩尔生成焓 

分 类 号：O642.3[理学—物理化学]