一个Yb_(8)簇合物的合成、结构及CO_(2)催化转化性质

Synthesis,crystal structure,and conversion of CO_(2) of a Yb_(8) cluster

使用多齿席夫碱配体H_(2)L与Yb(acac)3·2H_(2)O反应,设计并通过溶剂热法合成了一例结构新颖的八核镱簇合物[Yb_(8)(acac)4(HL)4(L)2(μ3-O)4(C2H_(5)O)4]·2C2H_(5)OH·2CH_(2)Cl2(1)。单晶X射线衍射分析表明,簇合物呈中心对称的八核结构,中心稀土离子Yb1(Ⅲ)为八配位的双帽三角棱柱几何构型,Yb2、Yb3和Yb4均为七配位,分别为单帽三角棱柱、五角双锥及单帽八面体几何构型。簇合物1具有良好的溶剂稳定性。近红外荧光测试表明:簇合物1在室温下表现出Yb(Ⅲ)特征发射峰。此外,催化性质研究表明:簇合物1可以有效地催化CO_(2)与环氧化合物的环加成反应,且作为异相催化剂表现出良好的循环性能。

A novel and interesting Yb_(8) cluster,namely[Yb_(8)(acac)4(HL)4(L)2(μ3-O)4(C2H_(5)O)4]·2C2H_(5)OH·2CH_(2)Cl2(1)(H_(2)L=2-hydroxy-benzoic acid(5-hydroxymethyl-furan-2-ylmethylene)-hydrazide,and Hacac=acetylacetone),has been constructed by using a polydentate Schiff base ligand(H_(2)L).X-ray diffraction analysis indicates that cluster 1 shows a central symmetric octanuclear structure.The eight-coordinated Yb1(Ⅲ) ion possesses a distorted bi-augmented trigonal prism geometrical configuration;while the three seven-coordinated Yb(Ⅲ) ions(Yb2,Yb3,and Yb4)possess capped trigonal prism,pentagonal bipyramid,and capped octahedron geometrical configuration,respectively.Cluster 1 possesses excellent solvent stability.Moreover,the photoluminescence property study shows that 1 displayed typical near-infrared luminescence of Yb􀃮at room temperature.Interestingly,cluster 1 exhibited high catalytic activity and can effectively catalyze the cycloaddition reaction of CO_(2) with various epoxides.As a heterogeneous catalyst,cluster 1 showed good cycling performance.CCDC:2098280.