Three-Dimensional Metal-Organic Frameworks Based on Functionalized Tetracarboxylate Linkers: Synthesis, Strucures, and Gas Sorption

New tetracarboxylate ligands with dihydroxy (L-1) and crown ether functionalities (L-2) have been synthesized and treated with Cull and Zn-II ions to generate three-dimensional (3D) metal-organic frameworks (MOFs) with the compositions of [Cu-2(L-1)(H2O)(2)]center dot 14DMF center dot 10H(2)O, 5, [Cu-2(L-2)(H2O)(2)]center dot 12DMF, 6, [Zn-6(mu(4)-O)(L-1)(2)(L-1-H-2)center dot 35DMF center dot 27H(2)O, 7, and [Zn3Na2(L-2)(2)(DMF)(2)]center dot 7DMF center dot 14H(2)O, 8. The four compounds show different framework structures with different connectivities. Compound 5 exhibits the PtS topology whereas compound 6 has a [6(4).8(2)](3)[6(6)] topology. Compound 7 adopts a new [4.6(5)] [4(2).6(8)][4(4).6(2)][4(5).6][4(8).6(10).8(3)] topology while compound 8 exhibits the Flu topology. The porosity and H-2 uptake were studied by gas sorption experiments and grand canonical Monte Carlo (GCMC) simulations. Compound 5 shows a high H2 uptake of up to 1.11 wt % at 77 K.