Transformation of MOF Secondary Building Units into Hexa-nuclear Zr-Alkyl Catalysts for Ethylene Polymerization
Journal of the American Chemical Society | 12 Aug 2017
P Ji, JB Solomon, Z Lin, A Johnson, RF Jordan and W Lin
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. MOF nodes can thus be directly transformed into novel single-site solid organometallic catalysts without homogeneous analogs for polymerization reactions.
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