一个新颖的三维异核锑(Ⅲ)-镨(Ⅲ)配合物[Sb_2-μ_4-(EDTA)_2Pr(H_2O)_5]NO_3·4H_2O的合成、晶体结构及热分解研究

Synthesis,Crystal Structure and Thermal Decomposition of a Novel 3D Heterometallic Sb(Ⅲ)-Pr(Ⅲ) Complex [Sb_2-μ_4-(EDTA)_2Pr(H_2O)_5]NO_3·4H_2O

合成了锑-镨与乙二胺四乙酸形成的新颖三维配合物[Sb2-μ4-(EDTA)2Pr(H2O)5]NO3·4H2O,用元素分析、红外光谱、热分析及X射线单晶衍射法等进行了组成和结构表征.结果表明该配合物属正交晶系,空间群Pnn2;晶胞参数:a=1.07031(2)nm,b=2.30805(4)nm,c=0.72343(2)nm,V=1.78711(7)nm3,Z=2,Dc=2.202g/cm3,F(000)=1164,μ=2.955mm-1,GOF=1.000,最终偏离因子R1=0.0203,wR2=0.0545[I>2σ(Ⅰ)].在标题化合物中,每个镨(Ⅲ)离子的配位数为9,与五个水分子中的五个氧原子和四个羧基氧原子配位,形成三帽三角棱柱空间配位多面体.锑(Ⅲ)与EDTA离子中的四个氧原子和两个氮原子配位,在赤道平面上有一孤对电子.同时讨论了配合物的热分解过程.

A novel 3D EDTA-linked（EDTA=ethylenediamine-N,N,N＇,N＇-tetraacetate）heterometallic antimony-praseodymium complex [Sb2-μ4-（EDTA）2Pr（H2O）5]NO3？4H2O has been synthesized and characterized by elemental analysis,FT-IR spectrum,TG-DSC and X-ray diffraction analyses.It crystallizes in the orthorhombic system,space group Pnn2 with α=1.07031（2）nm,b=2.30805（4）nm,c=0.72343（2）nm,V=1.78711（7）nm^3,Z=2,Dc=2.202 g/cm^3,F（000）=1164,μ=2.955 mm^-1,GOF=1.000,the final R1= 0.0203 and wR2=0.0545 [I〉2σ（I）].In the title complex,the Pr（Ⅲ）ion is nine-coordinated.The coordination polyhedron around each praseodymium atom is a distorted tricapped trigonal prism with four oxygen atoms from four carboxylic groups and five oxygen atoms from five H2O molecules.The Sb（Ⅲ）ion is coordinated by two N atoms and four O atoms from an EDTA,together with a lone electron pair in the equatorial position.It shows the possible pyrolysis reactions of experimental and calculated percentage mass losses in the thermal decomposition process.