Construction of Two Microporous Metal-Organic Frameworks with flu and pyr Topologies Based on Zn4(μ3-OH)2(CO2)6 and Zn6(μ6-O)(CO2)6 Secondary Building Units

By employment of a tripodal phosphoric carboxylate ligand, tris(4-carboxylphenyl)phosphine oxide (H3TPO), two novel porous metal organic frameworks, namely, [Zn-4(mu(3)-OH)(2)(TPO)(2)(H2O)(2)] (1) and [Zn-6(mu(6)-O)(TPO)(2)](NO3)(4)center dot 3H(2)O (2), have been synthesized by solvothermal methods. Complexes 1 and 2 exhibit three-dimensional microporous frameworks with flu and pyr topologies and possess rare butterfly-shaped Zn-4(mu(3)-OH)(2)(CO2)(6) and octahedral Zn-6(mu(6)-O)(CO2)(6) secondary building units, respectively. Large cavities and one-dimensional channels are observed in these two frameworks. Gas-sorption measurements indicate that complex 2 has a good H-2 uptake capacity of 171.9 cm(3) g(-1) (1.53 wt %) at 77 K and 1.08 bar, and its ideal adsorbed solution theory calculation predicts highly selective adsorption of CO2 over N-2 and CH4. Furthermore, complexes 1 and 2 exhibit excellent blue emission at room temperature.