Dioxole functionalized metal-organic frameworks.

The synthesis and physical properties of dioxole functionalized metal-organic frameworks (MOFs) are reported. Combination of benzo[d][1,3]dioxole-4,7-dicarboxylic acid (dioxole-BDC) and Zn(II) under solvothermal conditions yields either an isoreticular metal-organic framework analog (IRMOF-1-dioxole) or a new MOF material (MOF-1-dioxole). With the addition of a co-ligand, namely 4,4'-bipyridine, a mixed-linker Zn(II)-paddlewheel MOF (BMOF-2-dioxole) is obtained. The structure of all three MOFs has been determined by single-crystal X-ray diffraction studies. MOF-1-dioxole reveals that the dioxole group binds to the Zn(II) ions, while there is no such binding in IRMOF-1-dioxole or BMOF-2-dioxole, hence preserving the parent topology of these frameworks. Thermal gravimetric analysis and gas sorption studies reveal quite different physical properties for each of these functionalized MOFs.