Lanthanide and actinide m-terphenyl complexes

This PhD studentship supports an EPSRC New Investigator Award application, and thus the description matches that project.

This project seeks to develop the chemistry of low OS f-block (M2+) ions towards a deeper understanding of the properties that affect their valence electron configuration (VEC), and the potential for divergent chemistry driven by different VECs. Contemporary low oxidation state (OS), M2+, f-block chemistry has defined two classes of M2+ ion (where M = a lanthanide (Ln) or actinide (An) metal): fn+1 or fnd1 - in some cases both exist for the same metal with different ligand sets. Here we will target molecular design features to deliberately modulate the electronic configuration of rare-earth, Ln, and early actinide An ions in low OSs. This will afford unprecedented control over the physicochemical properties of these ions. We will achieve this by: 1) synthesising low OS f-block complexes using modular frameworks where ligand donor atoms can be altered without changing overall stereochemical properties; 2) using donor elements which are amenable to advanced spectroscopic characterisation; 3) characterising molecules by magnetism (SQUID), magnetic resonance (NMR, EPR), X-ray absorption spectroscopy (at metal edges), to deepen understanding of their electronic structure. This systematic approach has not yet been applied to this nascent research area and is a logical next step to expand its frontier. This work will produce fundamental knowledge to inform future work into configuration control of f-block ions, and redox-driven lanthanide/actinide chemistry.

Questions:
- Can we use soft- and hard-donor ligands which support metal-arene interactions to isolate low-oxidation state lanthanide and actinide complexes?
- What is the electronic structure of these complexes, does the electron density reside on the metal or ligand?
- Does this change with the donor type?
- Do these low oxidation state complexes react like traditional lanthanide complexes, or more like transition metals?

Approach:
- Design and synthesize ligands.
- Make complexes in readily available oxidation states.
- Reduce complexes to lower formal oxidation states.
- Characterize using state of the art experimental and theoretical approaches.
- Study reactivity using classical transition metal reaction classes.

Remit / themes:
- Synthetic coordination chemistry/
- Computational and theoretical chemistry.
- Condensed matter: electronic structure.
- Condensed matter: magnetism and magnetic materials.