Synthesis, Structure, and Metalation of Two New Highly Porous Zirconium Metal–Organic Frameworks

Three new metal–organic frameworks [MOF-525, Zr6O4(OH)4(TCPP-H2)3; MOF-535, Zr6O4(OH)4(XF)3; MOF-545, Zr6O8(H2O)8(TCPP-H2)2, where porphyrin H4-TCPP-H2 = (C48H24O8N4) and cruciform H4-XF = (C42O8H22)] based on two new topologies, ftw and csq, have been synthesized and structurally characterized. MOF-525 and -535 are composed of Zr6O4(OH)4 cuboctahedral units linked by either porphyrin (MOF-525) or cruciform (MOF-535). Another zirconium-containing unit, Zr6O8(H2O)8, is linked by porphyrin to give the MOF-545 structure. The structure of MOF-525 was obtained by analysis of powder X-ray diffraction data. The structures of MOF-535 and -545 were resolved from synchrotron single-crystal data. MOF-525, -535, and -545 have Brunauer–Emmett–Teller surface areas of 2620, 1120, and 2260 m2/g, respectively. In addition to their large surface areas, both porphyrin-containing MOFs are exceptionally chemically stable, maintaining their structures under aqueous and organic conditions. MOF-525 and -545 were metalated with iron(III) and copper(II) to yield the metalated analogues without losing their high surface area and chemical stability.