高氯酸镝与L-谷氨酸的反应热及标准生成焓的测定

Reaction heat and standard enthalpy of formation of dysprosium perchlorate coordinated with L-glutamic acid

合成了稀土高氯酸镝谷氨酸配合物晶体。经热重、差热、化学分析及对比有关文献,确定了其组成是Dy2(Glu)2(ClO4)4·9H2O,纯度是96.54%。选用Dy(NO3)3·6H2O,L Glu,NaClO4·H2O和NaNO3作辅助物,使用具有恒温环境的反应热量计和热化学手段,以2mol/LHCl作溶剂,分别测定了[2Dy(NO3)3·6H2O+2Glu+6NaClO4·H2O]和[Dy2(Glu)2(ClO4)4·9H2O+6NaNO3]在25℃时的溶解焓。通过设计热化学循环求得化学反应的反应焓ΔrHΘm,25℃=234.300kJ/mol,计算得到配合物Dy2(Glu)2(ClO4)4·9H2O(s)在25℃时的标准生成焓ΔfHΘm,25℃=-6476.116kJ/mol。

Rare-earth perchlorate complex compound coordinated with L-glutamic acid, Dy_2(Glu)_2(ClO_4)_4·9H_2O, was synthesized. By using TG, DTA and chemical analytic method and comparing with the literatures related, its structure was characterized with a purity of 96.54%. A thermochemical cycle was designed at 25?℃, the chemical reaction and standard enthalpy of formation were measured by a solution calorimeter, and the solution reaction of [2Dy(NO_3)_3·6H_2O+2Glu+6NaClO_4·H_2O] and [Dy_2(Glu)_2(ClO_4)_4·9H_2O+6NaNO_3] were carried out in an isoperibel reaction calorimeter, respectively. The calorimetric solvent used was 2 mol/L HCl. According to the results, the following data were obtained Δ_rH Θ_m=230.588?kJ/mol, Δ_fH Θ_m(Dy_2(Glu)_2(ClO_4)_4·9H_2O, s, 25?℃)=-6?479.828?kJ/mol.