A model for the homogeneous Cr-PNP (PNP = diphosphinoamine) ethylene trimerisation and tetramerisation catalyst system has been studied theoretically, with the aim of identifying suitable density functional theory methods for treatment of this catalyst, and evaluating the likely oxidation and spin states of the active species. Benchmarking studies involving high-level treatment reveal the difficulty of accurately calculating the thermochemistry of this system, and suggest that local density functionals, such as M06L, probably provide the best option. Density functional theory modelling of catalyst activation and the first steps of oligomerisation up until 1-hexene formation appears to favour a Cr^I–Cr^III mechanism, involving spin surface crossing from sextet to quartet states.

Item Type:	Refereed Article
Keywords:	chromium, catalysis, trimerization, tetramerization
Research Division:	Chemical Sciences
Research Group:	Other Chemical Sciences
Research Field:	Organometallic Chemistry
Objective Division:	Manufacturing
Objective Group:	Industrial Chemicals and Related Products
Objective Field:	Organic Industrial Chemicals (excl. Resins, Rubber and Plastics)
Author:	McGuinness, DS (Dr David McGuinness)
Author:	Yates, BF (Professor Brian Yates)
ID Code:	97337
Year Published:	2014
Funding Support:	Australian Research Council (FT100100609)
Web of Science® Times Cited:	6
Deposited By:	Chemistry
Deposited On:	2014-12-11
Last Modified:	2015-04-28
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