Dalton Discussion 14 – Advancing the chemistry of the f-elements, 28–30 July 2014, Edinburgh

The chemistry of the f-elements impacts upon many of the 21^st century chemical challenges requisite for a secure and sustainable future. Compounds of the f-elements often display unique chemical and catalytic reactivity not seen with other (transition) metals, and the inclusion of lanthanides and actinides into molecular and solid-state materials can have transformational effects on their properties and resulting applications. The prospect of new capacity and technological advances in low-carbon nuclear power generation has reinvigorated the search for new fuel materials and their sustainable and safe reprocessing, and has highlighted the need for a better understanding of the environmental chemistry of the f-elements. Significant advances in theoretical tools have allowed many aspects of molecular lanthanide and actinide chemistry to be modelled for the first time. The burgeoning roles of these elements and their compounds in much of modern metal-based chemistry formed the basis of Dalton Discussion 14 – Advancing the chemistry of the f-elements, which was held in Edinburgh on 28–30 July 2014 and attracted 100 or so delegates from around the world.

The meeting was divided into four cross-cutting themes: (1) probing structure and bonding in f-element compounds, (2) f-element properties and materials applications, (3) advances in f-element reactivity and catalysis, and (4) f-elements in the environment, with four plenary, four invited, and 16 contributing speakers and 35 poster presentations. These contributions ranged from the molecular to the extended structure and from in silico to the environment, providing a full and varied outlook of the area and a wealth of interesting material to discuss.

Laurent Maron (Toulouse) provided a general overview of f-element computational chemistry and showed how f-in-core calculations can be used to gain a deeper understanding of bonding and mechanism in organometallic actinide chemistry. Nik Kaltsoyannis (UCL) showed how quantum theory of atoms in molecules (QTAIM) can be exploited to determine the strength of actinide–element bonds. DFT was also applied to solvent extraction processes (Nicolas Sieffert, Jerzy Narbutt) and solid-state uranium oxides (Nick Brincat).

Jeffrey Long (UC Berkeley) introduced the state-of-the-art in molecular magnetism, and showed the potential impact that actinide materials in particular could have on raising block temperatures due to their large spin–orbit coupling and radial extension of the 5f orbitals. Marinella Mazzanti (Grenoble, now Lausanne) described uranium(III) siloxide complexes that showed reactivity towards CO₂ and CS₂, forming binuclear spin-coupled systems. The significance of polynuclear lanthanide complexes in NIR-visible light up-conversion and emission was highlighted (Claude Piguet and Stéphane Petoud), with Ln nanoparticles (Katherine Brown), host–guest assemblies (Thomas Just Sørensen), and Ln–hydroporphyrin dyads (Eszter Borbas) expanding this subject.

Geoff Cloke (Sussex) reported some significant advances in low oxidation state f-element chemistry of U(III) metallocenes and their unique coupling reactions with CO₂ and CO, and Paula Diaconescu (UCLA) showed how arene-bridged diuranium complexes could be used to prepare radical bipyridyl U(IV) complexes. The unusual liquid ammonia chemistry of the f-elements was highlighted (Florian Kraus), and uranium terephthalates moved us from the molecular to new uranium coordination polymer chemistry (Christophe Volkringer).

Melissa Denecke (KIT, Manchester) outlined the use of solution X-ray spectroscopic techniques to investigate the chemical structures of f-element compounds important in nuclear remediation and its understanding and development. The immobilisation of radionuclides in the environment by cytochromes and the development of industrial biotechnological pathways was discussed by Jon Lloyd (Manchester). Insight into ternary uranyl citrate systems (Tori Forbes), the use of polymeric extractants for the recovery of radionuclides (Bradley Holliday), and the application of ultrasound techniques in aqueous plutonium chemistry were also discussed (Matthieu Virot).

I hope that this special issue of Dalton Transactions reflects and expands upon the scientific excellence, diversity, and impact of the lanthanide and actinide chemistry that was discussed at DD14. The value of the long discussion periods was enormous, as delegates had time to digest information, formulate questions, and respond to the speakers’ answers. Even though DD14 was the penultimate Dalton Discussion meeting, I would hope that the detailed scientific questioning that this unique format facilitates is carried over into other, more traditional-style conferences – less lecturing, more time for discussion! Special thanks are due to the scientific organising committee (Polly Arnold, Euan Brechin, Michael Buhl, and Louise Natrajan), the RSC staff (Richard Walker, Kirsty Lunnon, and Chloe Pritchard), and to all of the delegates who made such excellent contributions to this meeting.

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