We report the stepwise and quantitative transformation of the Zr-6(mu(3)-O)(4)(mu(3)-OH)(4)(HcO(2))(6) nodes in Zr-BTC (MOF-808) to the [Zr-6(mu(3)-O)(4)(mu(3)-OH)(4)Cl-12](6-) nodes in ZrCl2-BTC, and then to the organometallic [Zr-6(mu(3)-O)(4)(mu(3)-OLi)(4)R-12](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.