White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

A Computational Study of Ruthenium Metal Vinylidene Complexes: Novel Mechanisms and Catalysis

Johnson, David (2013) A Computational Study of Ruthenium Metal Vinylidene Complexes: Novel Mechanisms and Catalysis. PhD thesis, University of York.

Text (David Johnson Thesis)
David Johnson Thesis.pdf
Available under License Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 UK: England & Wales.

Download (7Mb) | Preview


A theoretical investigation into several reactions is reported, centred around the chemistry, formation, and reactivity of ruthenium vinylidene complexes. The first reaction discussed involves the formation of a vinylidene ligand through non-innocent ligand-mediated alkyne-vinylidene tautomerization (via the LAPS mechanism), where the coordinated acetate group acts as a proton shuttle allowing rapid formation of vinylidene under mild conditions. The reaction of hydroxy-vinylidene complexes is also studied, where formation of a carbonyl complex and free ethene was shown to involve nucleophilic attack of the vinylidene Cα by an acetate ligand, which then fragments to form the coordinated carbonyl ligand. Several mechanisms are compared for this reaction, such as transesterification, and through allenylidene and cationic intermediates. The CO-LAPS mechanism is also examined, where differing reactivity is observed with the LAPS mechanism upon coordination of a carbonyl ligand to the metal centre. The system is investigated in terms of not only the differing outcomes to the LAPS-type mechanism, but also with respect to observed experimental Markovnikov and anti-Markovnikov selectivity, showing a good agreement with experiment. Finally pyridine-alkenylation to form 2-styrylpyridine through a half-sandwich ruthenium complex is also investigated. The mechanism for this process is elucidated, along with a description of the formation of the unexpected experimental deactivation product. Additionally the chemistry and bonding of pyridylidene complexes is also studied.

Item Type: Thesis (PhD)
Academic Units: The University of York > Chemistry (York)
Identification Number/EthosID: uk.bl.ethos.605333
Depositing User: Mr David Johnson
Date Deposited: 19 May 2014 14:04
Last Modified: 08 Sep 2016 13:30
URI: http://etheses.whiterose.ac.uk/id/eprint/6170

You do not need to contact us to get a copy of this thesis. Please use the 'Download' link(s) above to get a copy.
You can contact us about this thesis. If you need to make a general enquiry, please see the Contact us page.

Actions (repository staff only: login required)