The Chemistry of the Uranium-Nitride Triple Bond
Lead Research Organisation:
University of Nottingham
Department Name: Sch of Chemistry
Abstract
Metal-ligand multiple-bonds represent fundamental aspects of chemistry and underpin chemical structure, bonding, reactivity, and catalysis. Indeed, transition metal-carbon multiple bonds are the basis for the 2005 Nobel Chemistry Prize and transition metal-nitrogen triple bonds are well established and important intermediates in biological processes (nitrogenases) and ammonia synthesis. For uranium, the heaviest naturally occurring element, double bonds to oxygen, exemplified by the ubiquitous linear uranyl dication, and nitrogen are well known, and the area of uranium-carbon double bonds is burgeoning. A molecular uranium-nitrogen triple bond, known as a uranium nitride, was for decades the ultimate target in synthetic actinide chemistry; however it eluded all attempts to prepare it. Very recently, we made a landmark advance and prepared the first example of a molecular uranium-nitride triple bond (Science, 2012, 337, 717). Our breakthrough method utilises a very bulky ligand which generates a pocket at uranium in which to install the nitride, coupled to stabilisation during synthesis using a sodium cation, followed by gentle removal of the sodium to furnish the terminal nitride linkage. This project aims to exploit our advance in order to develop this exciting area so that we may map out the intrinsic structure and reactivity of the uranium-nitride triple bond. We will expand the range of uranium-nitride triple bonds with our proven method to generate a family of compounds so that meaningful comparisons can be made. Surprisingly, the 1909 Haber-Bosch patent for ammonia synthesis, where nitrides are implicated, clearly references uranium as the best catalyst. We therefore seek to assess the role of uranium-nitrides in ammonia synthesis to answer long-standing questions regarding the role of uranium. Furthermore, we will assess the potential of uranium-nitrides in atom-efficient N-atom transfer reactions which may straightforwardly be 15N-isotopically labelled. We will establish the intrinsic reactivity character of the uranium-nitride linkage and will test the hypothesis that our nitrides represent a hitherto unavailable entry point to long-targeted, high value uranium-carbon triple and heteroatom-free double bonds that have no precedent. We also seek to extend this chemistry to heavier analogues where the nitride nitrogen is replaced by a phosphorus or arsenic atom which will afford an opportunity to compare trends within a chemical group. We will combine synthetic and structural studies with interdisciplinary magnetometric, computational, and spectroscopic studies (EPSRC EPR National Service at Manchester University, far-IR at Stuttgart University, and XANES at Canberra University) to give a comprehensive understanding of uranium-nitrogen bonding. Our uranium-nitride linkage provides a unique opportunity to probe the nature and extent of covalency in uranium-ligand bonding. The issue of covalency in uranium chemical bonding is long-running, still hotly debated, and important because of the nuclear waste legacy which the UK already has. Spent nuclear fuel is ~96% uranium and the official Nuclear Decommissioning Authority figure for nuclear waste clean-up bill is 70 billion pounds. If we can better understand the chemistry of uranium this higher platform of knowledge may in the future contribute to ameliorating the UK's nuclear waste legacy.
Planned Impact
The 2009 EPSRC International Review of Chemistry stated: "The resurgence in radiochemistry is a potentially important development given the rising interest worldwide in nuclear power. There are obvious needs for better understanding of the chemistry related to the radioisotopes and for educating a new generation of personnel trained to deal with these materials. Moreover, this presents an opportunity to explore the fundamental chemistry of compounds rarely accessed in academic laboratories".
We therefore posit that this project will have significant impact, as evidenced by publication of our preliminary results. Furthermore, the proposed research will address many Grand Challenge issues identified by the EPSRC and will deliver the following tangible outcomes and inventions:
1. Delivery of a better understanding of actinide science;
2. Materials synthesis and small molecule activation and conversion into value-added products;
3. Fundamental scientific knowledge and understanding of academic and technological importance;
4. Maximise knowledge-exchange, -transfer, and -impact in exploitation, and commercialisation;
5. An early career researcher available for the UK economy, coupled to significant outreach.
In order to maximise the impact of our work, we will communicate and engage with the private and public sectors, academia, and the public through a series of activities with well-defined milestones and timelines.
Outreach: The PI has established a strong record of science communication through university open days, school visits, the Royal Society MP/Scientist Pairing Scheme, the 2012 Royal Society Summer Science Exhibition, the Sunday Times Magazine, and internationally acclaimed Periodic Videos and EPSRC funded MolVids. We will build on our approach by constructing a new website, producing new videos on uranium-nitride and the Haber-Bosch process, and use our 2012 public lecture experience to culminate with a Royal Society Summer Science Exhibition stand in Year 3.
Industry and Commerce: The Business Partnership Unit, which is uniquely embedded in chemistry at Nottingham, maintains an excellent awareness of industrial needs and will manage potential exploitation of research outputs. Progress will be regularly monitored and contact with end-users will be made as exploitable outputs are identified. As demonstrated by the letters of support for this Proposal the team already have established contacts with the nuclear industry and will develop them as appropriate. Through departmental advisory boards we have access to representatives from industry. Knowledge exchange will be exploited using standard protocols as collaborative opportunities are identified. The BPU has extensive experience of negotiating contracts covering collaboration, confidentiality, material transfer, and licenses and all necessary arrangements are in place with the project partners.
EU: The impact of this work will be maximised through the PI's COST Action at three levels: (i) annual talks at the Action meetings which are attended by EU f-element researchers at all levels; (ii) annual presentation of research to the COST Chemistry Domain Committee (DC) who regularly liaise with the EU Commission; (iii) participation in science fairs run by the COST Office in concert with the COST Committee of Senior Officials (CSO) which is attended by the EU Commission.
Training: The PDRA working on this research will gain a comprehensive background in uranium handling (a rare skill), synthesis, spectroscopy, magnetism, and computation. They will receive external RPS and UoN radiochemical training and attend conferences and exhibitions in addition to acquiring a host of transferable skills. This will enhance their career, make them very attractive, valuable candidates for scientific careers, and help restructure the UK science base.
We therefore posit that this project will have significant impact, as evidenced by publication of our preliminary results. Furthermore, the proposed research will address many Grand Challenge issues identified by the EPSRC and will deliver the following tangible outcomes and inventions:
1. Delivery of a better understanding of actinide science;
2. Materials synthesis and small molecule activation and conversion into value-added products;
3. Fundamental scientific knowledge and understanding of academic and technological importance;
4. Maximise knowledge-exchange, -transfer, and -impact in exploitation, and commercialisation;
5. An early career researcher available for the UK economy, coupled to significant outreach.
In order to maximise the impact of our work, we will communicate and engage with the private and public sectors, academia, and the public through a series of activities with well-defined milestones and timelines.
Outreach: The PI has established a strong record of science communication through university open days, school visits, the Royal Society MP/Scientist Pairing Scheme, the 2012 Royal Society Summer Science Exhibition, the Sunday Times Magazine, and internationally acclaimed Periodic Videos and EPSRC funded MolVids. We will build on our approach by constructing a new website, producing new videos on uranium-nitride and the Haber-Bosch process, and use our 2012 public lecture experience to culminate with a Royal Society Summer Science Exhibition stand in Year 3.
Industry and Commerce: The Business Partnership Unit, which is uniquely embedded in chemistry at Nottingham, maintains an excellent awareness of industrial needs and will manage potential exploitation of research outputs. Progress will be regularly monitored and contact with end-users will be made as exploitable outputs are identified. As demonstrated by the letters of support for this Proposal the team already have established contacts with the nuclear industry and will develop them as appropriate. Through departmental advisory boards we have access to representatives from industry. Knowledge exchange will be exploited using standard protocols as collaborative opportunities are identified. The BPU has extensive experience of negotiating contracts covering collaboration, confidentiality, material transfer, and licenses and all necessary arrangements are in place with the project partners.
EU: The impact of this work will be maximised through the PI's COST Action at three levels: (i) annual talks at the Action meetings which are attended by EU f-element researchers at all levels; (ii) annual presentation of research to the COST Chemistry Domain Committee (DC) who regularly liaise with the EU Commission; (iii) participation in science fairs run by the COST Office in concert with the COST Committee of Senior Officials (CSO) which is attended by the EU Commission.
Training: The PDRA working on this research will gain a comprehensive background in uranium handling (a rare skill), synthesis, spectroscopy, magnetism, and computation. They will receive external RPS and UoN radiochemical training and attend conferences and exhibitions in addition to acquiring a host of transferable skills. This will enhance their career, make them very attractive, valuable candidates for scientific careers, and help restructure the UK science base.
People |
ORCID iD |
Stephen Liddle (Principal Investigator) | |
J McMaster (Co-Investigator) |
Publications
Boronski JT
(2021)
A crystalline tri-thorium cluster with s-aromatic metal-metal bonding.
in Nature
Brown JL
(2016)
Neptunium and plutonium complexes with a sterically encumbered triamidoamine (TREN) scaffold.
in Chemical communications (Cambridge, England)
Chatelain L
(2020)
Terminal uranium(V)-nitride hydrogenations involving direct addition or Frustrated Lewis Pair mechanisms.
in Nature communications
Cleaves PA
(2014)
Two-electron reductive carbonylation of terminal uranium(V) and uranium(VI) nitrides to cyanate by carbon monoxide.
in Angewandte Chemie (International ed. in English)
Du J
(2021)
Dipnictogen f-Element Chemistry: A Diphosphorus Uranium Complex.
in Journal of the American Chemical Society
Du J
(2024)
f-Element heavy pnictogen chemistry
in Chemical Science
Du J
(2021)
Evidence for ligand- and solvent-induced disproportionation of uranium(IV).
in Nature communications
Du J
(2021)
Exceptional uranium(VI)-nitride triple bond covalency from 15N nuclear magnetic resonance spectroscopy and quantum chemical analysis.
in Nature communications
Du J
(2019)
Thorium- and uranium-azide reductions: a transient dithorium-nitride versus isolable diuranium-nitrides.
in Chemical science
Du J
(2024)
Correction: f-Element heavy pnictogen chemistry.
in Chemical science
Du J
(2019)
Thorium-nitrogen multiple bonds provide evidence for pushing-from-below for early actinides.
in Nature communications
Gardner B
(2013)
Small-Molecule Activation at Uranium(III)
in European Journal of Inorganic Chemistry
Gardner BM
(2017)
Evidence for single metal two electron oxidative addition and reductive elimination at uranium.
in Nature communications
Gardner BM
(2015)
Isolation of Elusive HAsAsH in a Crystalline Diuranium(IV) Complex.
in Angewandte Chemie (International ed. in English)
Gardner BM
(2015)
Triamidoamine uranium(IV)-arsenic complexes containing one-, two- and threefold U-As bonding interactions.
in Nature chemistry
Gardner BM
(2015)
An Inverted-Sandwich Diuranium µ-?(5):?(5)-Cyclo-P5 Complex Supported by U-P5 d-Bonding.
in Angewandte Chemie (International ed. in English)
Gardner BM
(2015)
Uranium triamidoamine chemistry.
in Chemical communications (Cambridge, England)
Gardner BM
(2014)
Triamidoamine-uranium(IV)-stabilized terminal parent phosphide and phosphinidene complexes.
in Angewandte Chemie (International ed. in English)
Gregson M
(2017)
The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes.
in Nature communications
King D
(2016)
Uranium halide complexes stabilized by a new sterically demanding tripodal tris ( N -adamantylamidodimethylsilyl)methane ligand
in Journal of Coordination Chemistry
King D
(2013)
Single-Molecule Magnetism in a Single-Ion Triamidoamine Uranium(V) Terminal Mono-Oxo Complex
in Angewandte Chemie International Edition
King D
(2014)
Progress in molecular uranium-nitride chemistry
in Coordination Chemistry Reviews
King DM
(2022)
Uranium-nitride chemistry: uranium-uranium electronic communication mediated by nitride bridges.
in Dalton transactions (Cambridge, England : 2003)
King DM
(2016)
Molecular and electronic structure of terminal and alkali metal-capped uranium(V) nitride complexes.
in Nature communications
King DM
(2013)
Isolation and characterization of a uranium(VI)-nitride triple bond.
in Nature chemistry
King DM
(2014)
Synthesis and characterization of an f-block terminal parent imido [U-NH] complex: a masked uranium(IV) nitride.
in Journal of the American Chemical Society
Liddle S
(2015)
Inverted sandwich arene complexes of uranium
in Coordination Chemistry Reviews
Liddle ST
(2015)
Improving f-element single molecule magnets.
in Chemical Society reviews
Liddle ST
(2015)
The Renaissance of Non-Aqueous Uranium Chemistry.
in Angewandte Chemie (International ed. in English)
Lu E
(2015)
Uranium-mediated oxidative addition and reductive elimination.
in Dalton transactions (Cambridge, England : 2003)
Moro F
(2013)
The inherent single-molecule magnet character of trivalent uranium.
in Angewandte Chemie (International ed. in English)
Patel D
(2013)
An actinide Zintl cluster: a tris(triamidouranium)µ3-?2:?2:?2-heptaphosphanortricyclane and its diverse synthetic utility.
in Angewandte Chemie (International ed. in English)
Patel D
(2015)
Synthesis and characterisation of halide, separated ion pair, and hydride cyclopentadienyl iron bis(diphenylphosphino)ethane derivatives.
in Dalton transactions (Cambridge, England : 2003)
Patel D
(2015)
Comments on reactions of oxide derivatives of uranium with hexachloropropene to give UCl 4
in New Journal of Chemistry
Patel D
(2013)
A triamido-uranium(V) inverse-sandwich 10p-toluene tetraanion arene complex.
in Dalton transactions (Cambridge, England : 2003)
Patel D
(2013)
Reductive assembly of cyclobutadienyl and diphosphacyclobutadienyl rings at uranium.
in Nature communications
Rookes TM
(2017)
Crystalline Diuranium Phosphinidiide and µ-Phosphido Complexes with Symmetric and Asymmetric UPU Cores.
in Angewandte Chemie (International ed. in English)
Rookes TM
(2018)
Actinide-Pnictide (An-Pn) Bonds Spanning Non-Metal, Metalloid, and Metal Combinations (An=U, Th; Pn=P, As, Sb, Bi).
in Angewandte Chemie (International ed. in English)
Seed JA
(2017)
Rare-Earth- and Uranium-Mesoionic Carbenes: A New Class of f-Block Carbene Complex Derived from an N-Heterocyclic Olefin.
in Angewandte Chemie (International ed. in English)
Stafford H
(2017)
Terminal Parent Phosphanide and Phosphinidene Complexes of Zirconium(IV).
in Angewandte Chemie (International ed. in English)
Wildman EP
(2016)
Thorium-phosphorus triamidoamine complexes containing Th-P single- and multiple-bond interactions.
in Nature communications
Wooles A
(2013)
ß-Diketiminate Derivatives of Alkali Metals and Uranium
in Organometallics
Description | Even though this project suffered from some PDRA turn-over it was very successful and generated a number of leading publications as listed in the publications section. The first appointee is now working for the nuclear division of Rolls Royce on defence-related activities and the second appointee is now working for a radioactive waste disposal company so both have ended up in nuclear-related jobs; this grant has therefore proven to be an excellent pipeline for young researchers into industry. Some of the results from this project went on to underpin future grant applications including an EPSRC Fellowship. |
Exploitation Route | Development of actinide chemistry and nanomagnetism. |
Sectors | Chemicals Electronics |
Description | To further develop our own research efforts and to underpin successful grant application to ERC and to underpin a pending application to EPSRC (fellowship, funded). |
First Year Of Impact | 2014 |
Sector | Chemicals,Other |
Impact Types | Economic |
Description | EPSRC Established Career |
Amount | £1,422,792 (GBP) |
Funding ID | EP/M027015/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2015 |
End | 09/2020 |
Description | European Commission (EC) |
Amount | £180,000 (GBP) |
Funding ID | Marie Curie IIF THOR 297888 |
Organisation | European Commission |
Sector | Public |
Country | European Union (EU) |
Start | 06/2012 |
End | 06/2014 |
Description | European Research Council |
Amount | £850,000 (GBP) |
Funding ID | 239621 |
Organisation | European Research Council (ERC) |
Sector | Public |
Country | Belgium |
Start | 01/2009 |
End | 09/2014 |
Description | European Research Council |
Amount | £1,900,000 (GBP) |
Funding ID | 612724 |
Organisation | European Research Council (ERC) |
Sector | Public |
Country | Belgium |
Start | 09/2014 |
End | 09/2019 |
Description | High Intensity High Sensitivity X-ray Diffraction Equipment |
Amount | £1,100,000 (GBP) |
Funding ID | EP/P001386/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2016 |
End | 10/2021 |
Description | Magnetic Properties Measurement System for Manchester and National EPR Facility |
Amount | £732,000 (GBP) |
Funding ID | EP/S033181/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 08/2019 |
End | 08/2024 |
Description | National Nuclear User Facility at the Centre for Radiochemistry Research (CRR) |
Amount | £4,420,000 (GBP) |
Funding ID | EP/T011289/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 11/2019 |
End | 05/2022 |
Description | Presidents Doctoral Scholarship |
Amount | £80,000 (GBP) |
Organisation | University of Manchester |
Sector | Academic/University |
Country | United Kingdom |
Start | 09/2016 |
End | 09/2021 |
Description | Royal Society of London |
Amount | £12,737 (GBP) |
Funding ID | RG110238 - Equipment Grant |
Organisation | The Royal Society |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 09/2011 |
End | 09/2012 |
Description | EPR |
Organisation | University of Manchester |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We provide materials for study. |
Collaborator Contribution | UK EPR service provides multi frequency and temperature experiments to spectroscopically probe our molecules. |
Impact | Publications in Science, Nature Family, JACS, Angewandte Chemie, see publication list for details. |
Start Year | 2009 |
Description | EPSRC UK EPR Service |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Department | National EPR Research Facility and Service Home |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We provide materials to be measured. |
Collaborator Contribution | The EPR service measures the EPR spectra of our compounds. |
Impact | Please see outputs associated with the grant. |
Start Year | 2012 |