Date of Award

12-2007

Level of Access Assigned by Author

Campus-Only Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Advisor

Alice E. Bruce

Second Committee Member

Mitchell R.M. Bruce

Third Committee Member

James McClymer

Abstract

A series of novel alkoxybiphenythiols [ROC12H8SH], (R= 6, 8, 10, 11,12, 14); were synthesized for the synthesis of a series of alkoxybiphenylgold(I) phosphine complexes [ROC12H8SAuPR'3], (R= 8,10, 12, 14), R'= PPh3,(R= 8, 14), R'= PMe3. The objective of the research was to study the thermotropic properties of the thiols and gold(I) complexes with polarized optical microscopy. 2,2'-biphenyldinuclear gold(I) phosphine compounds were also synthesized to compare triphenylphosphine and trimethylphosphine ligands and their influence on intermolecular interactions Synthesis of alkoxybiphenylthiols was performed by one of two methods. The first method was substitution of aryl bromide by ethylthiolate to form an alkoxybiphenylethylsulfide. This was then subjected to selective sulfide cleavage with Na metal followed by acidification. Purification was performed by crystallization. The second method involved the reaction of alkoxybiphenylbromide with butyllithium, followed by reaction with S8, and acidic work-up. The synthesis of alkoxybiphenylthiolatogold(I)phosphines was achieved by the reaction of alkoxybiphenylthiols in a two phase system of THF/ MeOH with K2CO3 and trimethylbenzylammonium chloride as a phase transfer catalyst. Purification was achieved by means of selective crystallization, and column chromatography. X-ray crystal structures of H17C8OC12H8SAuPMe3, C12H8(SAuPPh3)2, and C12H8(SAuPMe3)3 were obtained. Thermal studies using a hot stage and polarized optical microscope were performed on alkoxybiphenylthiols and alkoxybiphenylthiolatogold(I)phosphines complexes. Longer alkoxy chains resulted in lower melting points. The alkoxybiphenylthiols investigated possessed discreet reversible mesophases, while the alkoxybiphenylthiolatogold(I)phosphines possessed birefringent characteristics when melted until they reached an isotropic point, though they were not reversible upon cooling. The materials remained as oil after several days. When compared to the corresponding ligand, the melting behavior of the gold complexes was radically changed. Comparison of the POM of the series (RSH, RSAuPMe3, RSAuPPh3) reveal a pattern suggestive of intermolecular interactions involving gold-gold interactions.

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