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Title: NMR studies of some novel fluoro-iridium complexes
Author: Murdoch, Henry M.
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1991
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This thesis describes the formation of some iridium complexes which contain an -SF3 group. Although monosubstituted derivatives of SF4 have been reported in organic chemistry, the -SF3 ligand was previously unknown in transition metal complex chemistry. The first iridium complex containing an -SF3 ligand was the product of reaction between t-IrCl(CO)[P(CH2CH3)3]2 and SF4, the reaction being carried out in a d2-dichloromethane solution. As a result of variable temperature 19F(iH) and 31P[iH] n.m.r. studies, this complex was found to possess fluxionality at the -SF3 site and also to undergo fluorine exchange by an intermolecular mechanism. These processes were found to be influenced by the presence of HF. Further information about factors influencing this exchange was obtained from other halo- and pseudohalo-complexes containing the -SF3 group. Complexes with different phosphines (both alkyl and aryl) were also synthesized and investigated. Additional experiments showed that BF3 removes a fluoride from sulphur to generate a novel -SF2 ligand, which is isoelectronic with -PF2. The -SF2+ group can undergo nucleophilic substitution reactions with specific reagents, for example methanol, ethanol, CH3OSi(CH3)3 and (H3C)2NSi(CH3)3. The structure of the adduct formed between SF4 and trimethylamine [N(CH3)3] has been determined from solution 19F[^1H] n.m.r. studies. This has effectively resolved the problem of previous conflicting reports on the structure and doubts as to the existence of this species. Finally, the crystal structures of two complexes produced during the course of this work are reported. The compounds concerned are:- a new form of t-IrCl(CO)[P(C_6H_5)_3]_2 into which two d_2-dichloromethane molecules have been incorporated in the crystal lattice.- a sulphur dioxide SO_2, adduct of this complex unsolvated. The crystal structure of this compound has been previously reported, but was found to have different unit cell parameters.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available