CFA-7: an interpenetrated metal-organic framework of the MFU-4 family.

The novel interpenetrated metal-organic framework CFA-7 (Coordination Framework Augsburg University- 7), [Zn5Cl4(tqpt)(3)], has been synthesized containing the organic linker {H-2-tqpt = 6,6,14,14-tetramethyl-6,14-dihydroquinoxalino[2,3-b] phenazinebistriazole}. Reaction of H-2-tqpt and anhydrous ZnCl2 in N, N-dimethylformamide (DMF) yields CFA-7 as pseudo-cubic crystals. CFA-7 serves as precursor for the synthesis of isostructural frameworks with redox-active metal centers, which is demonstrated by postsynthetic metal exchange of Zn2+ by different M2+ (M = Co, Ni, Cu) ions. The novel framework is robust upon solvent removal and has been structurally characterized by single-crystal X-ray diffraction, TGA and IR spectroscopy, as well as gas sorption (Ar, CO2 and H-2).