稀土配合物Sm2(CH3COO)4(NO3)2(phen)2 的合成、 结构及非等温热分解动力学研究

在水-乙醇混合体系中, 将浓硝酸硝化的Sm2O3与1,10-邻菲啰啉反应, 用冰醋酸调节pH≈4, 形成醋酸根桥联的双核钐配合物［Sm2(CH3COO)4(NO3)2(phen)2］(phen=1,10-邻菲啰啉), 用元素分析、红外光谱和核磁共振谱等进行了表征, 并用X射线衍射测定了配合物的晶体结构, 此外, 对配合物进行了非等温热分解动力学研究. 该晶体属于三斜晶系, P1空间 群, 晶胞参数a=0.979 6(3) nm, b=0.981 3(4) nm, c=1.127 3(4) nm, α=106.666(5)°, β=113.034(5)°, γ=102.656(5)°, V=0.885 4(5) nm3, Z=1, μ=3.361 mm-1, Dc=1.915 g/cm3, F(000)=498, R1=0.059 6, wR2=0.144 8. 该配合物是双核分子, 2个Sm(Ⅲ)离子通过4个醋酸根的羧基桥联, 每个中心离子分别与周围5个来自羧基的桥氧原子、 一个硝酸根的两个氧原子和一个邻菲啰啉分子中的两个氮原子配位, 形成九配位扭曲多面体. 非等温热分解动力学研究结果表明， 配合物第一步热分解反应可能为二级反应, 其动力学方程为dα/dT=A/［βe-E/RT(1-α)2］, 分解反应的表观活化能为344.84 kJ/mol, 指前因子lnA=66.52.

Synthesis, Crystal Structure and Kinetics of Thermal Decomposition of Lanthanide Complex Sm2(CH3COO)4(NO3)2(phen)2

Reaction of nitrated Sm2O3 with 1,10-phenanthroline in the system of EtOH/H2O with pH≈4 adjusted by HAc resulted in a novel acetate anions bridged dinuclear Sm(Ⅲ) complex Sm2(CH3COO)4·(NO3)2(phen)2, the complex was characterized by elemental analysis, IR, NMR spectroscopy and the crystal structure was determined by X-ray diffraction. Besides, the kineticsof thermal decomposition of the complex was studied by thermal analysis technique under non-isothermal condition. The crystal structure belongs to the triclinic system, space group P1 with a=0.979 6(3) nm, b=0.981 3(4) nm, c=1.127 3(4) nm, α=106.666(5)°, β=113.034(5)°, γ=102.656(5)°, V=0.885 4(5) nm3, Z=1, μ=3.361 mm-1, Dc=1.915 g/cm3, F(000)=498, R1=0.059 6, wR2=0.144 8. The possible reaction mechanism was suggested to be a second order chemical reaction. The kinetic equation may be expressed as dα/dT=A/［βe-E/RT(1-α)2］. The apparent activation energy and pre-exponential factor of the reaction were 344.84 kJ/mol and lnA=66.52, respectively.