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dc.contributor.advisorField, John Stainer.
dc.contributor.advisorHaines, Raymond John.
dc.creatorWarwick, Barry.
dc.date.accessioned2020-04-23T08:10:33Z
dc.date.available2020-04-23T08:10:33Z
dc.date.created1995
dc.date.issued1995
dc.identifier.urihttps://researchspace.ukzn.ac.za/handle/10413/18277
dc.descriptionMasters Degree. University of KwaZulu-Natal, Pietermaritzburg.en_US
dc.description.abstractChapter 1 setves as an introduction to the synthesis and characterisation of copper(!), silver(!) and gold(!) complexes of the 2,6-bis( diphenylphosphino )pyridine { (Ph2P)2py}, phenylbis(2- pyridyl)phosphine {PhP(py)2 } and 2, 7-bis( diphenylphosphino )-4-methylnaphthyridine { (Ph2P)2menapy} ligands. A review of all the transition metal complexes of these ligands is presented. Particular attention is given to the modes of coordination that these ligands may adopt when coordinating to a transition metal. Chapter 2 describes the reactions of the (Ph2P)2py ligand with [Cu(MeCN)4](PF 6), [Cu( Tl 2- bipy)(MeCN)2J(PF 6), [Ag(COD)2](BF4) and [Ag(ri 2-bipy)(COD)](BF4) which result in the formation of the dinuclear ligand-bridged complexes [Cu2{μ-(Ph2P)2py}3](PF6) 2 (1), [Cu2{μ( P h2P)2PY }z( Tl 2 -bipy )z](PF 6)2 (2 ). [ Agz { μ -(Ph2P)2PY} 3)(BF 4)2 (3) and [ Ag2 { μ-(Ph2P)2PY} z( Tl 2 - bipy)2](BF4 ) 2 (4) respectively. The X-ray crystal structures of 1 and 3 reveal that the three (Ph)>)ipy ligands bridge the two metal atoms coordinating soley through their phosphorus atoms with the result that each metal atom has a trigonal geometry. The nitrogen atoms of the pyridines are left free resulting in a fairly open cavity in the centre of the complex cation. The cavity sizes are calculated to be 4.9 and 5.3 A for the copper and silver complexes respectively. It is suggested that these open cavities should be able to bind metal ions such as Cu~ and Ag+. Absorption and emission spectra were recorded for both complexes 1 and 3 and the effects of the addition of Cu+ and Ag+ ions on the emission spectra are discussed. These studies reveal that the emission spectra are indeed perturbed upon the addition of metal ions. The X-ray crystal structure of2 has been detennined confirming the presence of two bridging (Ph2P)2py ligands and a 2,2'-bipyridyl ligand chelating at each copper atom. Thus each copper atom has a tetrahedral geometry. Based on characterisation data the structure of 4 is proposed to be similar to the structure of 2 with a tetrahedral geometry around each silver atom. Chapter 3 describes the reaction of the ligand PhP(py)2 with [Cu(MeCN)4](PF6), [Ag(COD)2](BF4) and [Au(MeCN)2J(SbF6). The reaction with [Cu(MeCN)4J(PF6) afforded the dinuclear complex [Cu2{ μ-PhP(py)2}i{MeCN)2]{PF6) 2 (5) as a crystalline solid. Single crystals were obtained and a X-ray crystal structure revealed the first example of PhP(py)2 ·coordinating in a bridging fashion that has been characterised in this way. The ligand coordinates to the one copper atom through its phosphorus atom and to the other copper atom through its two nitrogen atoms. The coordination around each copper atom is completed by an acetonitrile ligand resulting in a tetrahedral geometry around each copper atom. The reaction of the ligand with silver(!) and gold(I) precursors resulted in ill-defined products that could not be isolated and characterised. Chapter 4 describes the synthesis of the novel (Ph2P)2menapy ligand and its reactions with [Cu(MeCN)4)(PF6), [Ag(COD)2](BF4) and [Au(MeCN)2)(SbF6). The ligand proved difficult to isolate as a pure solid and is extremely reactive towards oxygen. Reaction of the ligand with copper(!) and silver(Q precursors afforded crystalline solids which were characterised as [Cu2{μ( Ph?)imenapy}i(H2O)J(PFJ2 (6) and [Ag2{μ-(Ph2P)2menapy}i(H2O)4](BF4)2 (8). The structures of these two complexes are thought to consist of the two metal atoms bridged by two naphthyridyl ligands each bonded to the metal via the phosphorus atoms with the coordination at each metal being completed by two water molecules. This would result in a tetrahedral arrangement around each metal atom. To reduce the uncertainty of the proposed structures attempts at growing single crystals of both 6 and 8 were attempted. Single crystals were obtained in both cases but they proved to be too small for X-ray crystal structure analysis. Reaction of a mixture of the oxidised ligand 2-diphenylphosphineoxide-7-diphenylphosphine-4- methylnaphthyridine (Ph2POmenapyPPhi) and (Ph2P)2py resulted in the formation of a mixture of6 and [C11z(μ-PhiPOmenapyPPhi1(MeCN)J(PF6) 2 (7). A single crystal X-ray diffraction study has been performed on 7 which shows that the oxidised ligands bridge the two copper atoms; coordination at the one copper is through the phosphorus atom while the ligand chelates at the second copper via the oxygen and the adjacent naphthyridine nitrogen atom. The coordination at each copper atom is completed by an acetonitrile ligand resulting in a tetrahedral geometry. Reaction of the ligand with the gold(I) precursor afforded ill-defined products that could not be isolated.en_US
dc.language.isoenen_US
dc.subject.otherCharacterisation of copper.en_US
dc.subject.otherDiphenylphosphino.en_US
dc.subject.otherMethylnaphthyridine ligands.en_US
dc.subject.otherTransition metal.en_US
dc.titleDinuclear complexes of copper, silver and gold bridged by phosphoruspyridyl and phosphorusnaphthyridyl ligands.en_US
dc.typeThesisen_US


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