Stitching 2D Polymeric Layers into Flexible 3D Metal-Organic Frameworks via a Sequential Self-Assembly Approach

Article abstract of DOI:10.1021/acs.cgd.5b01772

Two-dimensional (2D) coordination polymer [Zn(ATZ)₂]_n (HATZ = 5-amino-1H-tetrazole) featuring a 2D + 2D → 2D pillar-layer array was synthesized, wherein two honeycomb-shaped Zn(ATZ)_1.5 sublayers can be stitched together by dicarboxylate bridging linkers of varied length and type to generate 4 three-dimensional (3D) isoreticular noninterperpentrated frameworks under solvothermal conditions. The interpenetration behavior may be constrained to some extent by the pillar length because a 3D twofold interpenetrated architecture was obtained with a longer ligand using a similar process. The pillar-exchange process enabled the facile synthesis of a family of isoreticular metal-organic framework structures with different flexibilities and interpenetration behaviors through the judicious choice of the type and size of the pillar units. Thermal analysis indicated that [Zn(ATZ)₂]_n also possesses excellent thermostability at a high decomposition temperature up to 356 °C. The kinetic parameters of its exothermic process were studied by Kissingers and Ozawa-Doyles methods. Furthermore, its luminescent properties at room temperature were also studied in detail.