Investigating Phthalate and 1,3-Diether Coverage and Dynamics on the (104) and (110) Surfaces of MgCl2‑Supported Ziegler–Natta Catalysts

In this work we present a systematic DFT analysis of the effect of surface coverage on the coordination properties of two industrial Lewis bases, dimethyl phthalate and 9,9-bis(methoxymethyl)fluorene, to the (104) and (110) surfaces of MgCl2. Further, we investigated several possible migration pathways for the migration of the Lewis bases on the same MgCl2 monolayer. Our study clearly shows that complete coverage of the Mg vacancies on the surface by coordinating dimethyl phthalate or 9,9-bis(methoxymethyl)fluorene is hampered by steric repulsion between vicinally coordinated donor molecules. Further, our study clearly indicates that both dimethyl phthalate and 9,9-bis(methoxymethyl)fluorene migration on the same MgCl2 monolayer on the (104) and (110) surfaces basically requires donor dissociation.