Use of 2,2-Bipyrimidine for the Preparation of UO₂²⁺-3d Diphosphonates

Three new multidimensional bimetallic UO22+-3d three-dimensional complexes were crystallized in high yield under mild hydrothermal conditions: [Mn­(H2O)]2­[(UO2)4­(PO3C6H4PO3)3­(bipym)]·​2H2O (1), [Ni­(H2O)]2­[(UO2)3­(O3PC6H4­PO3)­(O3PC6H4­PO3H)2­(bipym)]·​6H2O (2), and Zn­[(UO2)­(HO3PC6H4­PO3)­(HO3PC6H4­PO3H)0.5­(bipym)0.5] (3), where bipym = 2,2-bipyrimidine. The structure of 1 is composed of edge-sharing dimers of uranyl pentagonal bipyramids that are linked by rigid phenyl spacers to form pillared three-dimensional networks. This compound is remarkable in that the [Mn2(H2O)2(bipym)]4+ moiety is incorporated within the uranyl phosphonate frameworks without reducing the dimensionality of the overall structure. Compound 2 consists of uranyl tetragonal and pentagonal bipyramids that are linked by phosphonate groups to form a pillared three-dimensional framework with channels that are occupied by the [Ni2(H2O)2­(bipym)2]4+ moiety. In compound 3, edge-sharing dimers of uranyl pentagonal bipyramids are connected through the phosphonate ligand to create corrugated uranyl-phosphonate chains. The incorporated [Zn2(bipym)]4+ subunits are located within the interlayer of the uranyl-phosphonate chains. All three compounds are characterized by absorption, fluorescence, and infrared spectroscopy.我们在温和水热条件下以高产率结晶得到了三种新型双金属UO₂²⁺-3d三维配合物：[Mn(H₂O)]₂[(UO₂)₄(PO₃C₆H₄PO₃)₃(bipym)]·2H₂O（化合物1）、[Ni(H₂O)]₂[(UO₂)₃(O₃PC₆H₄PO₃)(O₃PC₆H₄PO₃H)₂(bipym)]·6H₂O（化合物2）以及Zn[(UO₂)(HO₃PC₆H₄PO₃)(HO₃PC₆H₄PO₃H)₀.₅(bipym)₀.₅]（化合物3），其中bipym（2,2'-联嘧啶，2,2-bipyrimidine）为配体。化合物1的结构由边共享的铀酰五角双锥二聚体构成，该二聚体通过刚性苯基间隔基连接形成柱撑三维网络。该化合物的独特之处在于，[Mn₂(H₂O)₂(bipym)]⁴⁺单元被嵌入铀酰膦酸盐骨架中，且未改变整体结构的维度。化合物2由铀酰四方双锥与五角双锥单元构成，这些单元通过膦酸酯基团连接形成带有孔道的柱撑三维骨架，孔道内填充有[Ni₂(H₂O)₂(bipym)₂]⁴⁺单元。在化合物3中，边共享的铀酰五角双锥二聚体通过膦酸酯配体连接形成波纹状铀酰-膦酸盐链，嵌入的[Zn₂(bipym)]⁴⁺亚单元位于该铀酰-膦酸盐链的层间区域。上述三种化合物均通过吸收光谱、荧光光谱及红外光谱进行了表征。