Crosby, Sarah H. (2011) Cyclometallated complexes of platinum : C-H activation, oxidation and reduction. PhD thesis, University of Warwick.

Research output not available from this repository, contact author.

Request Changes to record.

Abstract

Within this thesis, research related to the synthesis of Pt(II) and Pt(IV)
cyclometallated complexes involving both aryl and alkyl C-H activation is discussed.
The introduction reviews literature relevant to C-H activation, cyclometallation and
reductive elimination, both historic and current.
Four pyridine based pro-ligands, all with a 4-fluorophenyl substituent and a varying
alkyl substituent, were synthesised in order to study both aryl and alkyl C-H
activation. Initial reactions with K2PtCl4 led to the cyclometallation of the phenyl
ring via a reversible aryl C-H activation, which then resulted in a variety of Pt(II)
complexes by the addition of different co-ligands. Oxidation of these Pt(II) species
gave Pt(IV) complexes, which subsequently underwent isomerisation to give the
thermodynamic product. For the DMSO derivatives this was shown to occur via five
coordinate complexes stabilised by agostic interactions with the alkyl chain and
resulted in the first crystallographically characterised oxygen bound DMSO Pt(IV)
complexes.
Pt(II) and Pt(IV) sp2 cyclometallated complexes, each with an sp3 agostic interaction,
were isolated and characterised when using the more sterically demanding tbutyl
derivative of the pro-ligand. Subsequent alkyl C-H activation of the tbutyl group was
observed via an intra-molecular transcyclometallation reaction to give complexes
with an sp3 cyclometallation. From these species a series of complexes with a
C(sp2)^N^C(sp3) tridentate ligand were also synthesised. It was also noted that a
reversible rollover reaction of the Pt(II) agostic complex occurred in DMSO solvent
by exchanging the C(sp2)^N cyclometallation for a C(sp2)^C(sp2) cyclometallation
via decyclometallation, rotation about the central C-C bond and subsequent C-H
activation.
Reductive elimination of a chloride ligand with both sp2 and sp3 cyclometallated
carbons occurred to give functionalised phenyl rings and tbutyl groups, respectively.
Steric interactions were shown to play a major role in these reactions.

Item Type:	Thesis or Dissertation (PhD)
Subjects:	Q Science > QD Chemistry
Library of Congress Subject Headings (LCSH):	Organometallic compounds, Activation (Chemistry), Platinum, Complex compounds, Oxidation, Reduction (Chemistry)
Official Date:	June 2011
Dates:	Date Event June 2011 Submitted
Institution:	University of Warwick
Theses Department:	Department of Chemistry
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Rourke, Jonathan P.
Sponsors:	Warwick Postgraduate Research Scholarship (WPRS)
Extent:	xvii, 273 leaves : illustrations.
Language:	eng

Request changes or add full text files to a record

Repository staff actions (login required)

View Item