Show simple item record  

dc.contributor.authorKilpin, Kelly Joanen_NZ
dc.date.accessioned2009-07-13T14:58:42Z
dc.date.available2009-07-29T11:008:17Z
dc.date.issued2009en_NZ
dc.identifier.citationKilpin, K. J. (2009). The Chemistry of Cycloaurated Complexes (Thesis, Doctor of Philosophy (PhD)). The University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/2810en
dc.identifier.urihttps://hdl.handle.net/10289/2810
dc.description.abstractNew cycloaurated complexes have been synthesised and characterised. The biological and catalytic activity (in the addition of 2-methylfuran to methyl vinyl ketone) of selected complexes was evaluated. New complexes reported in this thesis where fully characterised by NMR (¹H, ¹³C and ³¹P when appropriate) and IR spectroscopy, ESI-mass spectrometry and elemental analysis. The simple cycloaurated iminophosphoranes (2-AuCl₂C₆H₄)Ph₂P=N-R (R = (R,S)-CHMePh, (S)-CHMePh, p-C₆H₄F or But) were synthesised by the reaction of the appropriate ortho-mercurated compound with [Me₄N][AuCl₄] and [Me₄N]Cl in acetonitrile; the complex (2-AuCl₂C₆H₄)Ph₂P=N-(S)-CHMePh was structurally characterised. The cis chloride ligands on the complexes were replaced by chelating dianionic ligands such as thiosalicylate and catecholate - the resulting bis-metallacyclic complexes have a better anti-tumour activity (against P388 murine leukemia cells) than the parent dichlorides. The nitrogen-gold coordinate bond is relatively robust and is not cleaved by cyanide or dithiocarbamate ligands. The reaction of (2-AuCl₂C₆H₄)Ph₂P=N-Ph with PPh₃ results in substitution of the chloride ligand trans to the nitrogen (shown by an X-ray crystal structure). Both the endo ((2-AuCl₂C₆H₄)Ph₂P=NC(O)Ph) and exo ((2-AuCl₂C₆H₄)C(O)N=PPh₃) cycloaurated isomers of the stabilised iminophosphorane Ph₃P=NC(O)Ph were synthesised and structurally characterised. Cycloaurated Ph₃P=S and Ph₃P=Se were synthesised by a transmetallation reaction from 2-Hg[(C₆H₄)P(E)Ph₂]₂ (E = S or Se). The synthesis of cycloaurated Ph₃P=O by an analogous method was unsuccessful. PhP(S)(NEt₂)₂ was also cycloaurated via a transmetallation reaction. X-ray crystallography confirmed the sulfur (not the nitrogen) was coordinated to the gold centre. The complexes show a similar stability and reactivity to the C,N cycloaurated species - the cis chloride ligands can be replaced by the chelating thiosalicylate ligand. Again the bis-metallacyclic species showed better biological activity than the parent dichloride. The direct reaction of the 2-pyridyl sulfonamide ligands 2-(C₅H₅N)CH₂NHSO₂R (R = p-tolyl, Ph or Me), 2-(C₅H₅N)CH₂CH₂NHSO₂R (R = p-tolyl or Ph) or 8-(p-tosylamino)quinoline with refluxing aqueous H[AuCl₄] gave N,N' coordinated complexes containing a five- or six-membered cycloaurated ring. The cycloaurated complexes derived from the ligands 2-(C₅H₅N)CH₂NHSO₂Me and 8-(p-tosylamino)quinoline were structurally characterised. The cycloaurated N,N' systems were not as stable as the C,N systems - reaction with reducing agents led to reduction of Au(III) to Au(I) and elemental gold. The 2-pyridine thiocarboxamide ligands 2-(C₅H₅N)C(S)NHR (R= p-tolyl, CH₂Ph, Me, p-C₆H₅OMe) also underwent direct cycloauration upon reaction with H[AuCl₄]. Coordination via the pyridyl nitrogen and sulfur atom was confirmed by an X-ray crystal structure of cycloaurated 2-(C₅H₅N)C(S)NHCH₂Ph. The N,S cycloaurated systems show poor stability in solution and decompose relatively quickly so applications are limited. The ligand with a 2 pyridyl substituent reacted with H[AuCl₄] in a different manner. Instead of cycloauration, the ligand was oxidised and an internal cyclisation occurred to give a 1,2,4-thiadiazolo[2,3-a]pyridinium heterocyclic ring. The reaction of the cycloaurated dichloride complexes (2-benzylpyridine)AuCl₂ and (2-AuCl₂C₆H₄)Ph₂P=N-Ph with the tripodal Kläui ligands (Na[(C₅H₅)Co{P(O)R₂}₃], R = OMe or OEt) and Tl[BF₄] resulted in the formation of cationic gold(III) salts. In the solid state the Kläui ligand is strongly coordinated through two of the three oxygen atoms, and weakly by the third, giving the gold a distorted square pyramidal geometry. In solution there is rapid interchange between the coordinated and non-coordinated oxygen atoms.en_NZ
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/zip
dc.language.isoen
dc.publisherThe University of Waikatoen_NZ
dc.rightsAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectgolden_NZ
dc.subjectcycloaurated complexesen_NZ
dc.titleThe Chemistry of Cycloaurated Complexesen_NZ
dc.typeThesisen_NZ
thesis.degree.disciplineScience and Engineeringen_NZ
thesis.degree.grantorUniversity of Waikatoen_NZ
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy (PhD)en_NZ
uow.date.accession2009-07-13T14:58:42Zen_NZ
uow.date.available2009-07-29T11:008:17Zen_NZ
uow.identifier.adthttp://adt.waikato.ac.nz/public/adt-uow20090713.145842en_NZ
pubs.elements-id18571
pubs.place-of-publicationHamilton, New Zealanden_NZ


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record