Evaluation of the Potential of [{Me2C(Cp)2}Zr(Me)]+ and [{Me2C(Cp)2}Zr(H)]+ as Single-Site Catalysts for Controlled Methyl Vinyl Ether Polymerizations by Density Functional Calculations

Abstract

Density functional calculations were carried out on the B3LYP level of theory to study the initiation and propagation steps of polymerization of methyl vinyl ether (MVE) using [Me2C(Cp)2Zr(Me)]+ and [Me2C(Cp)2Zr(H)]+ as catalysts. From the obtained results it is concluded that initiation is possible in general with [Me2C(Cp)2Zr(H)]+ as the catalyst and unlikely to happen with [Me2C(Cp)2Zr(Me)]+. Also with [Me2C(Cp)2Zr(H)]+ active propagation channels were found, which generally render the polymerization possible. However, the range of suitable reaction conditions appears to be so narrow that subtleties, which cannot be treated easily in a computational study, might still prevent polymerization. Furthermore, inactive but not irreversible propagation paths were found, which lead to species that are favored energetically compared to species in active reaction channels. This finding also hints at a successful polymerization to be problematic but not necessarily impossible. Also, the search for a catalyst precursor compoundwhich was located as [Me2C(Cp)2Zr(H)(Ph)]was successful.