Crystalline zinc diphosphonate metal-organic framework with three-dimensional microporosity.

While typically structures from linear diphosphonate ligands form dense phases, we report that with the functionalized ligand 1,4-dihydroxy-2,5-benzenediphosphonate (DHBP) and Zn2+ a microporous network is formed. {[Zn(DHBP)](DMF)2} (1; DMF = dimethylformamide) possesses three-dimensional microporosity as shown by X-ray diffraction and confirmed by CO2 and N2 sorption studies. Compound 1 is composed of one-dimensional columns of tetrahedral Zn ions with homoleptic phosphonate coordination. This infinite building unit enables a robust and porous yet still crystalline material.