Structural diversity of four new metal-organic frameworks with a curved tetracarboxdiimide dicarboxylic acid

Four new metal-organic frameworks (MOFs), {[Co-2(L)(2)(DMF)(3)]center dot 6.5DMF center dot 5H(2)O}(n) (1), {[Cu(L)(H2O)]center dot 2DMA}(n) (2), {[Zn-2(L)(DMF)(2)(HCOO)(2)]center dot 3DMF center dot 2H(2)O}(n) (3), and {[Cd-2(L)(2)(DMF)(H2O)(mu(2)-OH2)(2)]center dot 3.5DMF center dot 2H(2)O}(n) (4) (H2L = N-phenyl-N'-phenylbicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxdiimide dicarboxylic acid; DMA = N,N-dimethylacetamide; DMF = N,N-dimethylformamide) have been synthesized under solvothermal conditions. MOFs 1, 2 and 3 display various interesting two-dimensional (2D) structures, including 2D lattice structure, 2-fold interpenetrated 2D structure, and 2D tube-based network. MOF 4 features an interesting two-fold interpenetrated 3D structure possessing a 6-connected pcu network with the point symbol of {4(12)center dot 6(3)}. Photoluminescent properties of MOFs 3 and 4 have been investigated in the solid state at room temperature.