TY - JOUR T1 - Effect of donors on the activation mechanism in ziegler-natta catalysis: a computational study JF - Chemcatchem Y1 - 2016 A1 - Kumawat, Jugal A1 - Gupta, Virendra Kumar A1 - Vanka, Kumar KW - Alkylation KW - aluminum KW - Density functional calculations KW - surface chemistry KW - titanium AB -

Full quantum chemical calculations, using density functional theory (DFT), have been conducted to explain the effect of donors on the ``activation mechanism'' in the Ziegler-Natta (Z-N) catalyst system. In the activation mechanism, the inactive (TiCl4)-Cl-IV catalyst converts into the active (TiCl2Et)-Cl-III catalyst with the help of the AlEt3 present in the system. The donors that have been considered in this study are: ethyl benzoate (eb), two representative diether cases, a phthalate donor, and a silyl ester donor. The results indicate that eb and the diether donor cases donor have a negative effect on the barriers for the activation mechanism. However, the eb donor can be displaced from the MgCl2 surface by AlEt3, which matches experimental observations. For the phthalate, silyl ester and TiCl3-OC4H8Cl cases, the results indicate that a significant induction period would be present in Z-N systems employing such donors or having such a catalytic center, before catalysis could commence.

PB - WILEY-V C H VERLAG GMBH CY - POSTFACH 101161, 69451 WEINHEIM, GERMANY VL - 8 IS - 10 U3 -

Foreign

U4 - 4.724 ER -