稀土脯氨酸配合物[Nd_2(L-pro)_6(H_2O)_4](ClO_4)_6的热化学研究

Thermochemical Study on Standard Enthalpies of Formation of Rare Earth with L-Proline [Nd_2(L-pro)_6(H_2O)_4](ClO_4)_6 Complexes

稀土氨基酸高氯酸盐 [Nd2 (pro) 6 (H2 O) 4](ClO4 ) 6 的标准生成焓数据未见有文献报道。用L 脯氨酸与稀土钕盐合成了稀土高氯酸盐L 脯氨酸配合物 ,经热重、差热、化学分析及对比有关文献 ,得知其组成是 [Nd2 (L pro) 6 (H2 O) 4](ClO4 ) 6 。采用具有恒温环境的反应热量计 ,以 2mol/LHCl作溶剂 ,NdCl3·6H2 O、L pro、NaClO4 ·H2 O和NaCl作辅助物 ,测定了 [2NdCl3· 6H2 O +6L pro +6NaClO4 ·H2 O]和 {[Nd2 (L pro) 6 (H2 O) 4](ClO4 ) 6 +6NaCl +1 4H2 O}在 2 98 1 5K时的溶解热。利用Hess定律设计一热化学循环求得化学反应的反应焓ΔrH m =-2 0 840kJ/mol,由标准生成焓热力学数据求得配合物 [Nd2 (L pro) 6 (H2 O) 4](ClO4 ) 6 (s)在 2 98 1 5K时的ΔfH m (2 98 1 5K) =-65 2 3 496kJ/mol。

Crystals of complex compounds of rare-earth perchlorate with L-proline, [Nd 2(L-pro) 6(H 2O) 4](ClO 4) 6, were synthesized. Their structures were characterized using TG, DTA, chemical analytic method and comparison with relative literatures. Using a solution-reaction isoperibol calorimeter, solution heat of the [2NdCl 3· 6H 2O + 6L-pro + 6NaClO 4·H 2O] and｛[Nd 2(L-pro) 6(H 2O) 4](ClO 4) 6 + 6NaCl +14H 2O｝ were firstly measured in 2 mol/L HCl solvent, respectively. Standard enthalpy of formation of the crystals was calculated by Hess Law and a designed thermochemical cycle at 298.15 K. According to the results, the reaction enthalpy and standard enthalpy of formation were obtained:Δ rH  m(cycle)=-20.840 kJ/mol,Δ fH  m([Nd 2(L-pro) 6(H 2O) 4](ClO 4) 6, s, 298.15 K)=-6 523.496 kJ/mol.