3 years ago

Alkylation of titanium tetrachloride on magnesium dichloride in the presence of Lewis bases

Alkylation of titanium tetrachloride on magnesium dichloride in the presence of Lewis bases
We report the first quantum chemical description of the initial steps of Ziegler–Natta olefin polymerization catalysis involving all the relevant catalyst components. TiCl4 binds on the (104) surface of MgCl2 as a binuclear Ti2Cl8 and on the (110) surface as a mononuclear TiCl4, both binding modes being stabilized by octahedral six-coordination of Ti and Mg. Aluminum alkyl (triethylaluminum) coordinates to the MgCl2 surface via an unsaturated Cl to initiate catalyst alkylation reactions, thermodynamically driven by dimerization of the chlorinated aluminum alkyl. Addition of an internal donor (dimethyl phthalate) greatly stabilizes the (104) and (110) surfaces, ending up directing the alkylation reactions to the binuclear (104) site. External donor (dimethoxydimethylsilane) further assists the process, stabilizing similarly both catalytic surfaces. The spatial requirements of the donors are shown to be greater on the (110) surface than on the (104) surface, rationalizing the role of Lewis bases in the stereocontrol of polyolefins.

Publisher URL: www.sciencedirect.com/science

DOI: S0021951717302506

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.