Wednesday, 14 April 11:00am – 12:00pm

This seminar will be delivered via Zoom – Please email chemistry.researchsupport@sydney.edu.au for zoom link and password.

Speaker: Dr Witold Bloch; University of Adelaide

Host: Dr Derrick Roberts

Title: Linking cage compounds into processable porous materials

Bio: Wit obtained his PhD at the University of Adelaide in 2014 under the supervision of Christopher Sumby and Christian Doonan. After a short post-doctoral stint in the same group, he was awarded an Alexander von Humboldt post-doctoral fellowship. He carried out this fellowship in 2015-2017 in the Laboratory of Prof. Guido Clever (University of Goettingen and TU Dortmund, Germany) and his research project focused on advancing the structural complexity of coordination cages. In late 2017 Wit was awarded a University of Adelaide Ramsay fellowship which enabled him to commence his independent career. In 2019, he was awarded an ARC DECRA fellowship at the same institution. His current research is focused on the development of porous materials from metal-organic cage building blocks.

Abstract: Porous materials based on polymeric frameworks (e.g Metal-organic Frameworks) are increasingly being applied in topical areas such as gas separations, catalysis, and biomedicine. However, one of the challenges facing the adoption of these materials in industry is their limited processability, owing to their crystalline and brittle nature. Metal-organic cages are discrete and soluble compounds, and their synthetic versatility and inherent porosity make them attractive as a solution-processable functional-materials platform. In contrast to polymeric frameworks, metal-organic cages are first formed in solution and then assembled in the solid-state through covalent or non-covalent pathways. However, design principles to generate porous materials from this promising class of compounds is still underdeveloped.

Our recent work has examined the role that solvent plays in determining the non-covalent assembly and crystallization of Cu₄L₄ (L = dicarboxylate ligand) metal-organic cage solids.¹ Due to their solvatomorphism, the way that cage molecules order in the solid-state is extremely sensitive to the crystallization solvent and solvent diffusion kinetics. Ultimately, the crystallization conditions determine the formation of several different cage-based solids with tunable porosities. We have also explored the dependency of solvent to modulate the self-sorting of low-symmetry cage compounds generated from dynamic combinatorial libraries.² In doing so, we are assessing the important factors that contribute to the structure, stability and porosity of metal-organic cages.

We are also developing approaches to generate porous gels by covalently linking metal-organic cages. We have prepared a number of functionalized cage compounds with exterior aldehyde or amine substituents,³ and begun to explore their polymerization through the use of imine condensation chemistry. The preliminary results of this work will be discussed.

References

1         W. M. Bloch, R. Babarao and M. L. Schneider, Chem. Sci., 2020, 11, 3664–3671.

2         A. W. Markwell-Heys, M. L. Schneider,  J. M. L. Madridejos,  G.F. Metha and W. M. Bloch, Chem. Commun., 2021, DOI: 10.1039/D0CC08076D

3         M. L. Schneider, O. M. Linder-Patton and W. M. Bloch, Chem. Commun., 2020, 56, 12969–12972.