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

Abstract

Four new metal–organic frameworks (MOFs), {[Co₂(L)₂(DMF)₃]·6.5DMF·5H₂O}_n (1), {[Cu(L)(H₂O)]·2DMA}_n (2), {[Zn₂(L)(DMF)₂(HCOO)₂]·3DMF·2H₂O}_n (3), and {[Cd₂(L)₂(DMF)(H₂O)(μ₂-OH₂)₂]·3.5DMF·2H₂O}_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 {4¹²·6³}. Photoluminescent properties of MOFs 3 and 4 have been investigated in the solid state at room temperature.