The University of Southampton
University of Southampton Institutional Repository

An investigation of species involved in the methanol carbonylation reaction by exafs and ultramicroelectrodes

An investigation of species involved in the methanol carbonylation reaction by exafs and ultramicroelectrodes
An investigation of species involved in the methanol carbonylation reaction by exafs and ultramicroelectrodes

Extended X-ray absorption fine structure (EXAFS) spectroscopy was used to study the mechanistic cycles involved in the rhodium, iridium or palladium catalysed carbonylation of methanol. The validity of using microelectrodes to determine iodide concentrations, in particular HI, in acetic acid mixtures was also investigated.

EXAFS was used to characterise a number of catalytic precursors, revealing bond lengths that closely matched those reported in the literature using X-ray crystallography. Bond angles were also determined for some structures, either by using multiple scattering calculations or using trigonometry from distances obtained by the refinement of both transition metal and iodine edges.

In situ EXAFS experiments were also carried out. Stopped flow results, using the X-STRIP detector, for the oxidative addition of CH3OSO2CF3 to [Ir(CO)2I2]- showed a classic SN2 reaction, with the first step having occurred 1.2 ms into the reaction. [Pd(CO)I3]- was shown to be the dominant species in the palladium catalysed carbonylation cycle whilst the study of the [Bu4N][Rh(CO)2I2] catalysed carbonylation reaction, carried out in a newly designed cell, showed that only the species [Rh(CO)2I2]- was present during the timescale of the reaction; however little carbonylation occurred under these conditions. The crystal structure of [(CO3CO)Rh(dppe)I2], obtained from the catalytic reaction of [Rh(CO)I(dppe)], MeI and methanol demonstrated that the oxidative addition and methyl migration steps occurred.

University of Southampton
Bolton, Peter Roy
59919c59-a55a-44e6-ab01-b64cbf86c893
Bolton, Peter Roy
59919c59-a55a-44e6-ab01-b64cbf86c893
Denuault, Guy
5c76e69f-e04e-4be5-83c5-e729887ffd4e
Evans, John
05890433-0155-49fe-a65d-38c90ea25c69

Bolton, Peter Roy (2002) An investigation of species involved in the methanol carbonylation reaction by exafs and ultramicroelectrodes. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

Extended X-ray absorption fine structure (EXAFS) spectroscopy was used to study the mechanistic cycles involved in the rhodium, iridium or palladium catalysed carbonylation of methanol. The validity of using microelectrodes to determine iodide concentrations, in particular HI, in acetic acid mixtures was also investigated.

EXAFS was used to characterise a number of catalytic precursors, revealing bond lengths that closely matched those reported in the literature using X-ray crystallography. Bond angles were also determined for some structures, either by using multiple scattering calculations or using trigonometry from distances obtained by the refinement of both transition metal and iodine edges.

In situ EXAFS experiments were also carried out. Stopped flow results, using the X-STRIP detector, for the oxidative addition of CH3OSO2CF3 to [Ir(CO)2I2]- showed a classic SN2 reaction, with the first step having occurred 1.2 ms into the reaction. [Pd(CO)I3]- was shown to be the dominant species in the palladium catalysed carbonylation cycle whilst the study of the [Bu4N][Rh(CO)2I2] catalysed carbonylation reaction, carried out in a newly designed cell, showed that only the species [Rh(CO)2I2]- was present during the timescale of the reaction; however little carbonylation occurred under these conditions. The crystal structure of [(CO3CO)Rh(dppe)I2], obtained from the catalytic reaction of [Rh(CO)I(dppe)], MeI and methanol demonstrated that the oxidative addition and methyl migration steps occurred.

Text
885157.pdf - Version of Record
Available under License University of Southampton Thesis Licence.
Download (36MB)

More information

Published date: 2002

Identifiers

Local EPrints ID: 456031
URI: http://eprints.soton.ac.uk/id/eprint/456031
PURE UUID: 7fa35cec-414c-4c12-b32f-37a8cf7149ce
ORCID for Guy Denuault: ORCID iD orcid.org/0000-0002-8630-9492

Catalogue record

Date deposited: 12 Apr 2022 16:42
Last modified: 19 Aug 2022 01:32

Export record

Contributors

Author: Peter Roy Bolton
Thesis advisor: Guy Denuault ORCID iD
Thesis advisor: John Evans

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×