Building Precise Molecular Architectures to Unlock Remarkable f-Element Properties

Project Information

F-ELEMENT_ARCHITECT

Grant agreement ID: 816268

DOI

10.3030/816268

Project closed

EC signature date 25 February 2019

Start date 1 September 2019

End date 31 May 2025

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 990 800,93

EU contribution

€ 1 990 800,93

Coordinated by

THE UNIVERSITY OF MANCHESTER
United Kingdom

Periodic Reporting for period 3 - F-ELEMENT_ARCHITECT (Building Precise Molecular Architectures to Unlock Remarkable f-Element Properties)

Reporting period: 2022-09-01 to 2024-02-29

Summary of the context and overall objectives of the project

The f-elements, the lanthanides and actinides, are of huge technological importance. Societal benefits of the f-elements include optical and magnetic devices, batteries and civil nuclear power. However, f-element chemistry is underdeveloped compared to the s-, p- and d-blocks of the periodic table, and we now need to build a bigger knowledge platform to underpin current and future f-block applications. In this project, we target the synthesis of f-element complexes with precise linear or trigonal geometries. Such architectures are often difficult to achieve as f-element chemical bonding regimes are predominantly ionic, and this tends to favour the formation of different shapes.

Linear and trigonal f-element molecules have been shown to exhibit maximised magnetic and optical properties; for example axial dysprosium single-molecule magnets have shown magnetic memory effects at the highest temperatures to date, which could lead to high-density data storage applications. Linear and trigonal f-element compounds are also highly effective in stabilising unusual phenomena, such as low oxidation state compounds, which are of fundamental importance but have previously shown applications in organic synthesis. The relatively simple shapes of linear and trigonal molecules provides additional advantages in that their physical characterisation can be easier to interpret in high symmetry, and calculations to benchmark these results can be cheaper.

By using a combination of synthesis, characterisation and computational methods we target high-performing single molecule magnets, unusual low oxidation state compounds, and challenging measurements of small amounts of covalency in f-element chemical bonding. Together, these studies will push forward the research agenda in their respective disciplines, and will provide a combination of data that can be applied in future to real-world f-element technologies, such as improving recycling and separations platforms in nuclear fuel processes to increase efficiency and produce less waste.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the first four years of the project the team have performed a combination of synthesis, measurements and calculations to provide a large number of results. Our primary mechanism for dissemination of these results is in peer-reviewed journal articles, and as many of these projects are not yet published to prevent breaking embargos and export controls regulations, unpublished results will not be disclosed here. The results are also at too early a stage for consideration of commercial exploitation, thus we focus on dissemination activities here.

So far the team on this project have published 21 primary journal research papers. Highlights include:(i) the first example of a structurally characterised derivatised ferrocene anion (DOI:10.1038/s41557-020-00595-w); (ii) the use of 29Si NMR spectroscopy to probe f-element covalency (DOI:10.1021/jacs.1c03236); (iii) modelling magnetic relaxation in dysprosium single-molecule magnets (SMMs) (DOI:10.1021/acs.jpclett.1c02367); (iv) determining differences in electronic structures of early d- and f-block metal silanide complexes (DOI:10.1039/D2SC04526E); (v) assessing the effects of pressure on dysprosocenium SMMs (DOI:10.1039/D2CC06722F); (vi) measurement of the quantum tunnelling gap of a dysprosocenium SMM (DOI:10.1021/acs.jpclett.3c00034); (vii) an assessment of approaches to characterise magnetic relaxation on long timescales (DOI:10.1039/D3CP01278F); (viii) the use of the AtomAccess program to design new dysprosocenium SMMs (DOI:10.1021/jacs.3c08841); (ix) thermally stable Dy(II) and Tb(II) amidinate SMMs (DOI:10.1021/jacs.3c07978); (x) the use of pulsed EPR spectroscopy to study metal-carbon bonding in lanthanide tris-cyclopentadienyl complexes (DOI:10.1039/D3SC06175B); and, (xi) the first two coordinate dysprosium SMM (DOI:10.1021/jacs.3c12427).

The team have also contributed to 6 literature reviews in this area of relevance to the core aims of the grant to use time spent in pandemic shutdowns to good effect, including reviews of f-element heavy group 14 solution chemistry (DOI: 10.1039/D0SC04655H) f-element phospholyl chemistry (DOI:10.1002/chem.202005231) dysprosium alkoxide and aryloxide SMMs (DOI:10.1002/chem.202100085) an SMM book chapter (DOI:10.1002/9781119951438.eibc2784) metallocene anions (DOI:10.1002/ejic.202101063R1) and f-block heavy pnictogen chemistry (DOI:10.1039/d3sc05056d).

Dissemination activities over the last four years at conferences were initially hugely impacted by the pandemic, with many in-person delayed or cancelled. However the group have now given oral and poster contributions about this work at a large number of conferences (>20) and departmental seminars (>10). The activities include: (i) Numerous invited departmental seminars in the UK, France, India, Denmark, Switzerland, the Netherlands and Australia; (iii) Numerous f-element, coordination chemistry, magnetism and quantum conferences in the UK, USA, France, Germany, India, Denmark, Czechia, and Switzerland. (iii) Numerous online conferences. Both PDRAs and PhD students on this project have been awarded with best talk and best poster prizes.

Outreach opportunities were also been greatly limited by the pandemic initially. However, the group have managed to present the research activities of this project to the general public by: (i) Online seminars, radio shows, magazines and website blogs; and (ii) in-person events at stalls in Science fairs and festivals.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

We have shown over the last 18 months that despite the impact of the pandemic and the challenges associated with reduced/restricted lab time and remote working that we are able to continue progress towards the project aims. We have published advances in f-element synthesis, measurement and calculations, and we are now drafting manuscripts with advances that go beyond the state-of-the-art in f-element chemistry. We have continued to grow our activities with established collaborators, and instigated new collaborations, to target major advances in a wide range of technical areas and research fields. The results that will be obtained by the end of the project include the synthesis and study of f-element compounds with unusual geometries and oxidation states by innovative methods, leading to new insights into relaxation mechanisms of gold standard single-molecule magnets and unique approaches to measurements of f-element covalency. Taken together these studies will provide new insights into f-element electronic structures, for future exploitation in applied fields.

Summary