Adsorption Species of Ethyl Benzoate in MgCl2-Supported Ziegler−Natta Catalysts. A Density Functional Theory Study

Abstract

Adsorption species of ethyl benzoate (EB) on the (104) and (110) MgCl2 surfaces have been studied within DFT. As a result, monodentate and bidentate complexes of EB were obtained on both the MgCl2 surfaces. The bidentate structures on the (104) MgCl2 surface proved to be stabilized by the decreased distance between neighboring adsorption sites (surface Mg cations). The different affinity of EB for the five- and four-coordinated Mg cations predicted was suggested to be the cause of changing the equilibrium shape of MgCl2 crystals upon growing in the presence of EB: EB chemisorption seems to stabilize the (110) MgCl2 surface to a greater degree as compared to the (104) MgCl2 surface. The influence of EB coordination mode on active site stereoselectivity is discussed.