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.