Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article

Degree

Master of Science

Program

Chemistry

Supervisor

Corrigan, John F.

Abstract

Polynuclear Au (I) complexes exhibit rich photochemical properties and have the potential to find applications as molecular sensors, switches, or energy storage devices. Although dinuclear Au (I) complexes with bridging diphosphines have been extensively examined, most of those reported do not contain rigid-diphosphine ligands.

This thesis examines how the rigid diphosphine, 4,6-bis(diphenylphosphino)dibenzofuran (DBFDP) can be incorporated for the controlled assembly of photoluminescent gold (I) metal – chalcogenolate (chalcogenolate = RS-, RSe-; R = organic moiety) and gold (I) chalcogenide (chalcogenide = S2-, Se2-) bimetallic complexes. In these studies, the chalcogen reagents E(SiMe3)2 or RESiMe3 are reacted with the gold coordination complex [(AuOAc) 2(μ-dbfdp)] to yield [Au2E(μ-dbfdp)] and [(AuER)2(μ-dbfdp)], respectively, via the formation and elimination of AcOSiMe3. Further reaction of the [Au2E(dbfdp)] with AuOTf yields higher nuclearity clusters ranging from 4-6, namely [Au4(µ4-E)(µ-dbfdp)2](OTf)2 and [Au6(µ3-E)2(µ-dbfdp)3](OTf)2. A common feature among these di-gold complexes is the bridging nature of the DBFDP ligand.

The preparation, characterization, and photophysical properties of several of these and related gold-chalcogen assemblies clusters are presented.

Summary for Lay Audience

Group 11 coinage metals copper, silver, and gold in combination with group 16 elements, also known as chalcogens, such as oxygen, sulfur, selenium, and tellurium can form assemblies known as “group 11 metal chalcogenolate/chalcogenide clusters”. These clusters often have interesting physical properties such as photoluminescence, referring to the emission of light when excited with light of a higher energy. Phosphorus containing organic compounds (phosphine ligands) can provide stability to these chalcogenolate and chalcogenide clusters as well as introduce an additional method for changing their physical properties (e.g. luminescence). Chalcogenolates (RE-, R = organic substituent, E = O, S, Se, Te) have the ability to bond these group 11 metals which result in a M-E-R (M = Cu, Ag, Au) interaction. These R groups can be altered to provide kinetic control in the assembly of these compounds. Chalcogenides (E2-) can also be reacted with group 11 coinage metals and generally result in M2E core with a 2:1 ratio between M and E. Chalcogenides form the core alongside the group 11 metals which, are protected by the mentioned phosphine ligands. These clusters can have potential applications in light emitting materials, optical sensors, and bioimaging.

This thesis focuses on the incorporation of a custom phosphine ligand which has the ability to bridge two metal centres (here, Cu or Au). The incorporation of this phosphine ligand leads to chalcogenide complexes with the number of metal atoms ranging from 2-6. Additionally, different chalcogenolate ligands were also incorporated to study the effect of various R groups (Ph, C6F5).

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