The Fall 2022 GWC2 Seminar Series continues with our last presentation Wednesday, November 30th.
Preparing Group 11 Metal and Metal-Chalcogen Nanocluster Surfaces for “Click” Chemistry
Professor and Chair John Corrigan
Department of Chemistry
University of Waterloo
Wednesday, November 30, 2022
3:00 p.m.
C2-361 at the University of Waterloo - Coffee and snacks served.
Online via Microsoft Teams for the University of Guelph.
Please contact gwc@uoguelph.ca with your Teams ID/email address to attend the seminars online.
All are welcome to attend!
ABSTRACT: Unlike nanoparticles, the surface chemistry of atomically precise metal nanoclusters is far less developed as a support for anchoring functional groups. Nanocluster frameworks are generally passivated with inert surfaces that simply serve to kinetically stabilize the metal core against aggregation reactions. Although substitution reactions on nanoclusters can be used to introduce function, they typically suffer from incomplete replacement and/or framework degradation since they involve reactions at the metal surface. However, incorporating a ligand during nanocluster assembly that bears a specific chemical functionality allows a general method for preparing a functional surface amenable to the subsequent reaction chemistry.
The surfaces of monodisperse nanocluster platforms that contain azidemoieties as part of the organic ligand shell are being developed in a collaborative work in order to offer a simple route to introduce function onto nanocluster surfaces. For example, the -N3 moieties undergo strain-promoted alkyne-azide(SPAAC) cycloaddition reactions on the nanocluster surfaces, generally enabling selective incorporation of functionality with retention of the overall frameworks. However, the cluster-surface cycloaddition chemistry differs as the isomeric form of the surface ligand is changed. For example, the para-substituted gold nanocluster [Au25(SCH2CH2-para-C6H4-N3)18]1-has highest reaction rates towards SPAAC reactions, while the isomer [Au25(SCH2CH2-ortho-C6H4-N3)18]1-is not stable towards cluster-surface SPAAC chemistry. In this seminar, the approaches to tailoring the surfaces of Group 11 metal and metal-chalcogen nanoclusters will be discussed.