摘要
以4'-(2-吡啶基)-2,2':6',2"-三联吡啶(2-pyterpy)为配体,通过溶剂热法合成了 5个双核配合物[Ln(2-pyterpy)(NO3)2(μ-OCH3)]2(Ln-2-pyterpy,Ln=Pr、Sm、Eu、Dy、Er).单晶 X 射线衍射分析表明,配合物 Pr-2-pyterpy 和 Sm-2-pyterpy 同构,属于单斜晶系,P21空间群,a=0.956 43(19)nm,b=1.965 4(4)nm,c=1.193 5(2)nm,β=90.41(3)°.配合物Er-2-pyterpy 属于单斜晶系,C2/c空间群,a=2.838 8(6)nm,b=1.204 8(2)nm,c=1.520 6(3)nm,β=121.70(3)°.粉末X射线衍射研究表明,配合物 Eu-2-pyterpy 与 Dy-2-pyterpy同构且与文献报道的配合物[Ln(2-pyterpy)(NO3)2(μ-OCH3)]2(Ln=Tb,Dy)结构相同,属于单斜晶系,P21/n空间群.镧系收缩效应在调整该系列配合物结构中起到了重要作用.固态配合物Ln-2-pyterpy(Ln=Pr、Sm、Eu、Dy)均发射Ln(Ⅲ)的特征荧光.在300 K,配合物Ln-2-pyterpy(Ln=Pr、Sm、Eu、Dy)的xMT实验值与2个孤立的Ln(Ⅲ)离子的理论值基本一致.根据2 K时xMT实验值推断,配合物Sm-2-pyterpy和Eu-2-pyterpy的顺磁离子间分别通过甲氧基桥传递弱的反铁磁和铁磁耦合作用.
Abstract
Five dinuclear complexes[Ln(2-pyterpy)(NO3)2(μ-OCH3)]2(Ln-2-pyterpy,Ln=Pr,Sm,Eu,Dy,Er)were synthesized by solvothermal method using 4'-(2-pyridyl)-2,2':6',2"-terpyridine(2-pyterpy)as ligand.Single crystal X-ray diffraction analysis showed that complexes Pr-2-pyterpy and Sm-2-pyterpy are isomorphic and crystallize in monoclinic system,space group P2,with a=0.956 43(19)nm,b=1.965 4(4)nm,c=1.193 5(2)nm,β=90.41(3)°.Com-plex Er-2-pyterpy crystallizes in monoclinic system,space group C2/c with a=2.838 8(6)nm,b=1.204 8(2)nm,c=1.520 6(3)nm,β=121.70(3)°.Powder X-ray diffraction results showed that complexes Ln-2-pyterpy(Ln=Eu,Dy)are isomorphic and have the same structure as the reported complexes[Ln(2-pyterpy)(NO3)2(µ-OCH3)]2(Ln=Tb,Dy),crystallizing in monoclinic crystal system,space group P21/n.The lanthanide contraction effect plays an important role in adjusting the structure of this series of complexes.The solid complexes Ln-2-pyterpy(Ln=Pr,Sm,Eu,Dy)emitted the characteristic fluorescence of Ln(Ⅲ)ions.At 300 K,the xMT experimental values of complexes Ln-2-py-terpy(Ln=Pr,Sm,Eu,Dy)were consistent with the theoretical values of two corresponding isolated Ln(Ⅲ)ions.Ac-cording to the xMT experimental value at 2 K,the weak antiferromagnetic and ferromagnetic coupling effects be-tween the Ln(Ⅲ)ions of the complexes Sm-2-pyterpy and Eu-2-pyterpy are transmitted by methoxy-bridge,respec-tively.CCDC:2333490,Pr-2-pyterpy;2333491,Sm-2-pyterpy;2333483,Er-2-pyterpy.
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