Defining the Electronic Structures of f-Block Heavy Pnictogen Compounds

Objectives
The f-block elements, the lanthanides (Ln) and actinides (An), are of huge technological importance due to both their unique physicochemical properties and their use in nuclear fuel cycles. We propose that the synthesis and study of Ln and An heavy group 15 compounds will provide new insights into f-block electronic structure and will open up multiple pathways for future exploration. We will synthesise mononuclear Ln/An Pn compounds containing Pn-Si bonds, which can be readily cleaved to form polynuclear clusters, and to directly install Zintl ions at Ln/An sites to form polynuclear clusters directly. These compounds will be studied by a wide range of characterisation techniques, and judiciously selected reactivity studies will be performed.
This proposal brings together a team with a unique combination of skills to deliver: (i) Structurally analogous families of novel Ln and An heavy pnictogen (Pn) molecular compounds and polypnictogen clusters; (ii) Reactivity studies of Ln/An-Pn and Ln/An=Pn bonds; and, (iii) Comprehensive physical studies and high-level calculations to map electronic structures. Well-defined molecular compounds and clusters will provide transferrable data that can be later applied to industrially relevant bulk phosphide and arsenide materials.
Approach
The student will synthesise a range of air- and moisture-sensitive Ln/An Pn compounds, using Schlenk line and glove box techniques. Together with our collaborators these compounds will be studied by experimental techniques including solution and solid-state NMR, EPR, UV/Vis/NIR, luminescence, IR and X-ray absorption/emission spectroscopies, cyclic voltammetry, elemental analysis, SQUID magnetometry, single crystal and powder X-ray diffraction; physical data will be benchmarked by high-level density functional theory and ab initio calculations. Results will be disseminated in gold standard journals, international conferences, and press releases when appropriate. When applications are discovered, IP will be protected by patents and commercialised when required.

Fit to EPSRC Remit
This proposal is fully aligned to the most recent EPSRC Strategic Plan and Delivery Plan, Vision and Objectives. We will strengthen the EPSRC research area of "Synthetic Coordination Chemistry" as our creative synthetic methods to provide the target molecules can be applied to other projects. Characterisation of these compounds by advanced physical and computational studies will drive innovations and progress in technique development to make major contributions to multiple EPSRC research areas, including "Analytical Science", "Chemical Structure" and "Computational and Theoretical Chemistry;" collaborations that underpin this proposal with UK-based computational chemists, the EPSRC National EPR Facility and DLS are already in place. The PhD student will be trained in air-sensitive Ln and An chemistry, of strategic benefit to UK academia, the nuclear industry and the economy.