Two New Tetranuclear Cluster-based Coordination Polymers based on Isomorphic Semi-rigid Tetracarboxylate Ligands: Syntheses, Structures, and Luminescent Properties

Two new tetranuclear cluster-based compounds, namely [Cd 2 (L1)(H 2 O)(DMA)] n ( 1 ) and [Cd 2 Ba 2 (L2)(H 2 O) 6 (DMA)] n ( 2 ) [H 4 L1 = 3-(3',5'-dicarboxylphenoxy) phthalic acid, H 4 L2 = 6-(3',4'-dicarboxyl-phenoxy) isophthalic acid, DMA = N,N' -dimethylacetamide], were successfully synthesized under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction analyses. Compound 1 features a two-dimensional (2D) layered framework with tetranuclear [Cd 4 (COO) 6 ] clusters as building subunits, and can be simplified into a binodal (3, 6)-connected kgd topological network with the schläfli symbol of {4 3 } 2 {4 6 ;6 6 ;8 3 }, and compound 2 features a three-dimensional (3D) complicated framework based on heterometallic tetranulear [Cd 2 Ba 2 (COO) 8 ] cluster subunits, and can be simplified into a binodal (3, 6)-connected topological network. In addition, compounds 1 and 2 not only have high thermal stabilities but also show strong luminescent emissions at room temperature.