A series of isostructural hybrid bimetallic metal-organic frameworks (MOFs), Ni(x)M(1-x)-ITHDs [M = Zn(II), Co(II)], have been prepared via a conventional solvothermal reaction in the presence of varying mole ratios of Ni(II)/Zn(II) or Ni(II)/Co(II) mixed metal ions. While a critical amount of the doped Ni(II) ion (more than ≈0.2 mol fraction) is needed to have any enhancement of the framework stability of the hybrid bimetallic NixZn1-x-ITHDs, even a very small amount of the doped Ni(II) ion (≈0.1 mol fraction) produced a full enhancement of the framework stability of the hybrid bimetallic Ni(x)Co(1-x)-ITHDs. The highly porous and rigid Ni(x)Co(1-x)-ITHDs activated via a conventional vacuum drying process shows a Brunauer-Emmett-Teller specific surface area of 5370 m(2) g(-1), which is comparable to that of pure Ni-ITHD. The CO2 uptake capacities of Ni-ITHD and Ni(0.11)Co(0.89)-ITHD (2.79 and 2.71 g g(-1), respectively) at 1 bar and 195 K are larger than those of any other reported MOFs under similar conditions and the excess CO2 uptake capacity at 40 bar and 295 K (≈1.50 g g(-1)) is comparable to those of other MOFs, which are activated via the supercritical carbon dioxide drying process, with similar pore volumes.

A general strategy was developed for edge-directed self-assembly of tetragonal metal-organic polyhedra (MOPs) having a C(4) symmetry Cu(II)(2)(COO)(4) paddle-wheel as a secondary building unit, using C(2) symmetric dicarboxylic ligands as pincer-type primary building units.

A twofold interpenetrating polyhedron-based metal-organic framework with high hydrothermal stability was prepared using a rigid and bent C(2)-symmetric ligand containing two 3,5-benzenedicarboxylate units, which have large surface area and high uptake capacities for various gas molecules.

Single crystalline hollow metal-organic frameworks (MOFs) with cavity dimensions on the order of several micrometers and hundreds of micrometers were prepared using a metal-organic polyhedron single crystal as a sacrificial hard template. The hollow nature of the MOF crystal was confirmed by scanning electron microscopy of the crystal sliced using a focused ion beam.

Solvothermal reactions of manganese(II) chloride tetrahydrate with a bis-tetrazole ligand, 2,6-di(1H-tetrazol-5-yl)naphthalene (H(2)NDT), in N,N'-dimethylformamide (DMF)/MeOH mixed solvent at two slightly different temperatures, 75 and 100 °C, led to two different metal-organic frameworks (MOFs), [Mn(II)(3)O(HNDT)(2)(NDT)(DMF)(3)] (1) and [Mn(II)(5)O(2)(HNDT)(2)(NDT)(2)(DMF)(8)] (2), with different net topologies. Single-crystal X-ray diffraction studies reveal that 1 is constructed from an unprecedented trinuclear building block, [Mn(II)(3)O(CN(4))(6)], as a 6-connected trigonal prismatic secondary building unit (SBU) of topological D(3h) site symmetry, and that the ligand in the HNDT(-1)/NDT(2-) deprotonation states is a linker, where two tetrazole (CN(4)) groups of the ligand are connected via a rigid naphthyl group. The tetrazole groups in 1 adopt a 1,2-μ-bridging mode with the manganese(II) ions to form a μ(3)-oxo trinuclear SBU. The trigonalprismatic SBU in 1 is connected to six neighboring SBUs to form a three-dimensional MOF of acs net topology. 2 is constructed from an unprecedented pentanuclear building block, [Mn(II)(5)O(2)(CN(4))(8)], as an 8-connected tetragonal prismatic SBU of topological D(4h) site symmetry. The tetrazole groups in 2 adopt monodentate, 1,2-μ- and 2,3-μ-bridging bidentate and 1,2,3-μ-bridging tridentate binding modes with the manganese(II) centers to form a bis-μ(3)-oxo pentanuclear SBU of local C(2) site symmetry. The tetragonal prismatic SBU in 2 is connected to eight neighboring SBUs to form a 3-D MOF of bcu net topology.