Transformation of Metal–Organic Framework Secondary Building Units into Hexanuclear Zr-Alkyl Catalysts for Ethylene Polymerization
2017
Ji, Pengfei | Solomon, Joseph B. | Lin, Zekai | M. Wilders, Alison | Jordan, Richard F. | Lin, W. (Wenbin)
We report the stepwise and quantitative transformation of the Zr₆(μ₃-O)₄(μ₃-OH)₄(HCO₂)₆ nodes in Zr-BTC (MOF-808) to the [Zr₆(μ₃-O)₄(μ₃-OH)₄Cl₁₂]⁶– nodes in ZrCl₂-BTC, and then to the organometallic [Zr₆(μ₃-O)₄(μ₃-OLi)₄R₁₂]⁶– nodes in ZrR₂-BTC (R = CH₂SiMe₃ or Me). Activation of ZrCl₂-BTC with MMAO-12 generates ZrMe-BTC, which is an efficient catalyst for ethylene polymerization. ZrMe-BTC displays unusual electronic and steric properties compared to homogeneous Zr catalysts, possesses multimetallic active sites, and produces high-molecular-weight linear polyethylene. Metal–organic framework nodes can thus be directly transformed into novel single-site solid organometallic catalysts without homogeneous analogs for polymerization reactions.
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