Taking Actinides into the Third Dimension of the Periodic Table: Aromatic Thorium Superatom Clusters
Event details
| Date | 10.04.2025 |
| Hour | 16:00 › 17:30 |
| Speaker |
Stephen T. Liddle Department of Chemistry and Centre for Radiochemistry Research, The University of Manchester, Oxford |
| Location | |
| Category | Conferences - Seminars |
| Event Language | English |
Molecular metal-metal bonding is a widely studied area of chemistry, and over the best part of two centuries it
has become a mature field spanning numerous s-, p-, and d-block elements.1-3 In contrast, isolable actinideactinide
bonding remained elusive under regular experimental conditions, and examples were restricted to
diatomics in cryogenic inert matrices, gas-phase spectroscopic transients, or encapsulated in endohedral
fullerenes – these examples were not amenable to further study due to being too small scale or not ‘bottleable’.
Recently, as part of our work studying the cyclobutadienyl dianion,4-6 we discovered that actinide-actinide
bonding can be accessed in a trithorium cluster (a,b).7 This complex is notable not only for exhibiting actinideactinide
bonding in an isolable crystalline complex that can be made on macroscopic scale, but also because it
exhibits three-centre two-electron s-aromatic bonding that is quite unlike the traditional s-/p-/d- bonding motifs
commonly found in analogous transition metal bonding.8 More recently, this work has developed to now include
three-centre one-electron clusters,9 leading to the discovery that both the two- and one-electron clusters exhibit
exalted diamagnetism, which is an experimentally observable consequence of aromaticity. Furthermore, we have
expanded the range of trithorium clusters,10 enabling the thorium-thorium bonding to be experimentally
visualised using quantum crystallography.11 When taken together, this has all led to the recognition that these
one- and two-electron clusters are superatoms, that is superalkali (or supercoinage) and superalkaline,
respectively.
Overall, this work has revealed experimentally-mapped thorium-thorium bonding that is aromatic, hence
generating experimentally observable exalted diamagnetism, and so introduced the actinides to the superatom
concept, elucidating underpinning links to other element groups in the ‘third dimension’ of the Periodic Table.
References
1. F. A. Cotton, C. A. Murillo, R. A. Walton (ed), Multiple Bonds Between Metal Atoms, 3rd Edition, Springer-Verlag,
2005.
2. G. Parkin (ed), Metal-Metal Bonding, Springer-Verlag, 2010.
3. S. T. Liddle. (ed), Molecular Metal-Metal Bonds: Compounds, Synthesis, Properties, Wiley-VCH, 2015.
4. D. Patel, J. McMaster, W. Lewis, A. J. Blake, S. T. Liddle, Nat. Commun. 2013, 4, 2323.
5. J. T. Boronski, L. R. Doyle, J. A. Seed, A. W. Wooles, S. T. Liddle, Angew. Chem. Int. Ed. 2020, 59, 295.
6. J. T. Boronski, A. J. Wooles, S. T. Liddle, Chem. Sci. 2020, 11, 6789.
7. J. T. Boronski, J. A. Seed, D. Hunger, A. W. Woodward, J. van Slageren, A. J. Wooles, L. S. Natrajan, N.
Kaltsoyannis, S. T. Liddle, Nature 2021, 598, 72.
8. J. Tomeček, S. T. Liddle, N. Kaltsoyannis, ChemPhysChem 2023, 24, 202300366.
9. J. A. Seed, X. Deng, J. Tomeček, A. Brookfield, D. Collison, F. Tuna, A. J. Wooles, G. F. S. Whitehead, N.
Kaltsoyannis, S. T. Liddle, Nat. Chem. 2025, 17, accepted, in press.
10. X. Deng, J. A. Seed, J. Tomeček, A. Brookfield, D. Collison, F. Tuna, A. J. Wooles, N. Kaltsoyannis, S. T. Liddle,
unpublished results.
11. F. Meurer, X. Deng, J. A. Seed, M. Bodensteiner, S. T. Liddle, unpublished results
Practical information
- General public
- Free
Organizer
- Prof. Marinella Mazzanti - Group of Coordination Chemistry
Contact
- Prof. Marinella Mazzanti