|Wednesday, January 20|
Recent Advances in Luminescent Gold-Containing Molecular Functional Materials
* Vivian Wing-Wah Yam, University of Hong Kong, China
In this webinar, recent advances in the design and synthesis of novel classes of luminescent gold complexes with functional properties will be described. The chromophoric and luminescence properties have been studied and their spectroscopic origins elucidated. Correlations of the chromophoric and luminescence behavior with the electronic and structural properties of the gold complexes have been made. The characteristics of these complexes can be tailored for specific applications including as molecular materials for optoelectronics, electronics and stimuli-responsive functions.
Coordination and Metallic Clusters of Gold with New Ligand Types
* John F. Corrigan, University of Western Ontario, Canada
The chemistry of atomically precise gold clusters continues to develop at a rapid pace. In the first part of this seminar, how N-heterocyclic carbene (NHC) ligands play an emerging role in gold-chalcogenide cluster science will be highlighted. NHCs can be used to effectively stabilize polymetallic assemblies of Au(I) and, when merged with the rich luminescence features of heterometallic group 11-chalcogenide clusters, they offer an ability to probe composition/structure/property relationships systematically. This has enabled a series of isostructural coordination clusters [(NHC)4Au4M4(μ3-E)4] (M = Ag, Au; E = S, Se, Te) to be prepared where systematic replacement of the central metals and/or chalcogen is possible. Phosphorescence is observed from all clusters and emission energies can be varied based on the choice of metal and chalcogen within structurally identical cluster cores. Higher nuclearity cluster frameworks are also accessible using this approach. In the second part of this seminar, the tailoring of Au nanoclusters via interfacial surface chemistry will be described. In a collaborative work, the thiolate surfaces of monodisperse [Au25(SCH2CH2-C6H4-N3)18]- platforms that contain azide moieties as part of the ligands are being developed, the make-up of the surfaces confirmed by single crystal X-ray analysis and spectroscopic techniques. The -N3 moieties can undergo strain-promoted alkyne-azide cycloaddition reactions on the cluster surfaces, enabling selective incorporation of functionality with retention of the Au25 frameworks.