Synthesis of hetero-multinuclear metal complexes containing lanthanide ions

合成了V(V)-Ce(IV)-V(V)三核配合物[{V^VO2(L)}2Ce^&lt；IV&gt；]和V(V)-Ln(III)-Ln(III)-V(V)四核配合物[{V^VO2(L)Ln^&lt；III&gt；(Acac)}2(H2O)]{Ln=Eu，Gd，Tb；H3L：N，N‘-bis-3-ethoxysalicylidene-2-hydroxy-1，3-propanediamine；HacAc：2，4-戊二酮}。通过X-射线晶体结构分析确定了化合物的结构。二氧钒(V)部分的基氧原子与中心稀土离子配位形成三核或四核结构。V(V)-Ce(IV)三核配合物的钒-基氧原子距离(1.711(3)Å)大于V(V)-Ln(III)四核配合物(1.664(4)-1.675(4)Å)。V(V)-Ce(IV)三核配合物的基氧原子与Ce(IV)离子的配位比V(V)-Ln(III)四核配合物对Ln(III)离子的配位更强。三核和四核配合物结构的不同可能与稀土离子的不同氧化状态有关。V(V)-Ce(IV)三核络合物的循环伏安曲线显示一个准可逆的双电子氧化还原对，E_&lt；1/2&gt；=-0.60V vs.Fc/Fc^+。观察到V(V)-Tb(III)四核配合物的溶剂依赖性荧光。

A V(V)-Ce(IV)-V(V) trinuclear complex, [{V^VO_2(L)} _2Ce^<IV>] and V(V)-Ln(III)-Ln(III)-V(V) tetranuclear complexes, [{V^vO_2 (L)Ln^<III>(acac)}_2(H_2O)]{Ln=Eu, Gd, Tb ; H_3L : N,N'-bis-3-ethoxysalicylidene-2-hydroxy-1,3-propanediamine ; Hacac:2,4-pentanedione} were prepared. The structures of the complexes were determined by X-ray crystal structure analysis. The basal oxo atoms of the dioxovanadium(V) moieties are coordinated to the central lanthanide ions to form trinuclear or tetranuclear structures. However, the vanadium-basal oxo atom distance of the V(V)-Ce(IV) trinuclear complex (1.711(3)Å) is longer than those of the V(V)-Ln(III) teranuclear complexes (1.664(4)-1.675(4)Å). The basal oxo atoms of the V(V)-Ce(IV) trinuclear complex are coordinated to the Ce(IV) ion more strongly than those of the V(V)-Ln(III) tetranuclear complexes to the Ln(III) ions. The difference between the structures of trinuclear and tetranuclear complexes can be related to the different oxidation states of the lanthanide ions. The cyclic voltammogram of the V(V)-Ce(IV) trinuclear complex shows a quasi-reversible two-electron redox couple with E_<1/2> = -0.60 V vs. Fc/Fc^+. Solvent-dependent fluorescence was observed for the V(V)-Tb(III) tetranuclear complex.