Wednesday, 20 April 4:00pm – 5:00pm

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

Speaker: Dr Chris Hawes; School of Chemical and Physical Sciences, Keele University, UK

Host: Dr Lauren Macreadie

Title: Ligand Design for Stability and Functionality in Metal-Organic Frameworks and Coordination Cages

Abstract: Metal-Organic Frameworks (MOFs) and related materials now account for over 10% of all entries in the Cambridge Structural Database,1 and have seen ever-increasing popularity in inorganic and materials science research. However, MOF-based technologies are hampered by recurring issues around stability and cost, limiting their application scope. Wider exploration of ligand-centred functionalities may provide solutions. While most of the naturally-occurring metals in the periodic table are represented in MOF chemistry, most draw from only a handful of ligand classes: aromatic carboxylates, imidazolates and benzimidazolates, and symmetric pyridines, pyrazolates or phosphonates.2 \

Our goal is to explore new heterocycles and aliphatic MOF ligands, exploiting the hydrolysis resistance offered by strong metal-azolate bonds and the extra opportunities for stabilisation or backbone functionality in these systems (Figure 1). Our interest has been on three particular classes of linkers:

• Pyrazolopyridines
• Pyrrolo[3,2-b]pyrroles
• Spirocycles and fused polycyclic amines

Each shows useful properties when acting as ligands in extended networks.3 This seminar will outline our progress in using these building blocks to construct MOFs and coordination assemblies.

Figure 1 Examples of porous MOFs and coordination assemblies prepared from the three linker classes (left to right); pyrazolopyridines, pyrrolo[3,2-b]pyrroles, fused polycyclic amines

References
1. P. Z. Moghadam, A. Li, S. B. Wiggin, A. Tao, A. G. P. Maloney, P. A. Wood, S. C. Ward and D. Fairen-Jimenez, Chem. Mater. 2017, 29, 2618-2625
2. F. A. A. Paz, J. Klinowski, S. M. F. Vilela, J. P. C. Tomé, J. A. S. Cavaleiro and J. Rocha, Chem. Soc. Rev. 2012, 41, 1088-1110
3. A. M. Swarbrook, R. J. Weekes, J. W. Goodwin and C. S. Hawes, Dalton Trans. 2022, 51, 1056- 1069; C. S. Hawes, G. M. Ó Máille, K. Byrne, W. Schmitt and T. Gunnlaugsson, Dalton Trans. 2018, 47, 10080-10092; V. D. Slyusarchuk and C. S. Hawes, CrystEngComm 2022, 24, 484-490