Activated niobium and tantalum imido complexes: from tuneable polymerization to selective ethylene dimerization systems

Messinis, Antonis; Batsanov, Andrei; Howard, Judith; Hanton, Martin; Dyer, Philip William

doi:10.1002/cctc.201801849

Activated niobium and tantalum imido complexes: from tuneable polymerization to selective ethylene dimerization systems

Messinis, Antonis; Batsanov, Andrei; Howard, Judith; Hanton, Martin; Dyer, Philip William

Authors

Antonis Messinis

Dr Andrei Batsanov a.s.batsanov@durham.ac.uk
Academic Visitor

Judith Howard

Martin Hanton

Professor Philip Dyer p.w.dyer@durham.ac.uk
Professor

Abstract

The niobium and tantalum imido complexes [CpMCl2(NDipp)], [MCl3(NR)(dme)] (R = tBu, Ph, 2,6‐iPr2C6H3 (Dipp), and Mes), and [TaCl3(NDipp)(tmeda)] were tested in combination with EtAlCl2 for the dimerization of ethylene. The niobium systems afforded dimers or polymers, depending on the nature of the imido ligand, with overall productivities in the range 720 to 13,720 (mol C2H4)(mol Nb)‐1. The nature of the polyethylene produced (LDPE or HDPE) depended on the imido ligand and the niobium concentration at which catalysis was run. In contrast, the tantalum/dme systems all mediated ethylene dimerization with productivities of up to 4,503 (mol C2H4)(mol Ta)–1, with overall selectivities to butenes of between 73 ‐ 81 wt%; selectivity within the dimer fraction to 1‐butene was in the range 72 to 100%. The productivity of [TaCl3(NDipp)(tmeda)] was six times higher than that of its dme‐bearing counterpart, but at the cost of selectivity to 1‐butene. For the tantalum imido‐mediated ethylene dimerization the composition of the product slate formed is indicative of a metallacyclic mechanism being operative.

Citation

Messinis, A., Batsanov, A., Howard, J., Hanton, M., & Dyer, P. W. (2019). Activated niobium and tantalum imido complexes: from tuneable polymerization to selective ethylene dimerization systems. ChemCatChem, 11(6), 1756-1764. https://doi.org/10.1002/cctc.201801849

Journal Article Type	Article
Acceptance Date	Jan 14, 2019
Online Publication Date	Jan 15, 2019
Publication Date	Mar 20, 2019
Deposit Date	Jan 18, 2019
Publicly Available Date	Jan 15, 2020
Journal	ChemCatChem
Print ISSN	1867-3880
Electronic ISSN	1867-3899
Publisher	Wiley
Peer Reviewed	Peer Reviewed
Volume	11
Issue	6
Pages	1756-1764
DOI	https://doi.org/10.1002/cctc.201801849

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Copyright Statement
This is the peer-reviewed version of the following article: Messinis, Antonis, Batsanov, Andrei, Howard, Judith, Hanton, Martin & Dyer, Philip William (2019). Activated niobium and tantalum imido complexes: from tuneable polymerization to selective ethylene dimerization systems which has been published in final form at https://doi.org/10.1002/cctc.201801849. This article may be used for non-commercial purposes in accordance with Wiley-VCH Terms and Conditions for Self-Archiving.