Synthesis of hetero-multinuclear metal complexes containing lanthanide ions

合成了V（V）-Ce（IV）-V（V）三核配合物[{V^VO_2（L）} _2Ce^<IV>]和V（V）-Ln（III）-Ln（III）-V（V）四核配合物[{V^vO_2（L）Ln^<III>（acac）}_2（H_2O）]{Ln=Eu，Gd，Tb ; H_3L：N，N ′-双-3-乙氧基水杨醛-2-羟基-1，3-丙二胺; Hacac：2，4-戊二酮}。通过X-射线晶体结构分析确定了配合物的结构。二氧钒（V）部分的基础氧原子与中心镧系元素离子配位以形成三核或四核结构。但V（V）-Ce（IV）三核配合物的钒-基底氧原子距离（1.711（3）&lt;$）比V（V）-Ln（III）三核配合物的钒-基底氧原子距离（1.664（4）-1.675（4）&lt;$）长。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）四核配合物的基氧原子与Ln（III）离子的配位强。三核和四核配合物的结构差异可能与镧系离子的不同氧化态有关。V（V）-Ce（IV）三核配合物的循环伏安图显示出准可逆的两电子氧化还原电对，E &lt;1/2&gt; = -0.60 Vvs. Fc/Fc^+。V（V）-Tb（III）四核配合物具有溶剂依赖性荧光。

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.