Redox-responsive Magnetic Materials based on Polynuclear Organometallics

Informations projet

RMTBRC

N° de convention de subvention: 752684

DOI

10.3030/752684

Projet clôturé

Date de signature de la CE 10 Mars 2017

Date de début 1 Juillet 2017

Date de fin 15 Juillet 2020

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 246 668,40

Contribution de l’UE

€ 246 668,40

Coordonné par

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
France

Periodic Reporting for period 2 - RMTBRC (Redox-responsive Magnetic Materials based on Polynuclear Organometallics)

Période du rapport: 2019-07-01 au 2020-06-30

Résumé du contexte et des objectifs généraux du projet

This project involves the synthesis of redox-responsive magnetic materials based on metal clusters, with functionality arising from their highly unusual electronic and magnetic properties (giant spin states and slow magnetic relaxation). The multitude of oxidation states for the metal clusters (up to nine) results in a large variety of materials to be accessed. The project involved experts from France, UK and USA with complementary skills in synthesis, materials science and chemical physics in order to explore these novel materials as for use in charge- and data-storage.
Various areas of investigation (which are to published in due course) included:
1) coordination of bidentate ligand molecules to vacant metal sites on hexairon clusters to form coordination polymers
2) modification of the ortho-phenylenediamine ligand framework in order to shift (oxidatively and reductively) the potentials of hexairon cluster redox events
3) synthesis of a series of hexacobalt clusters, and comparison of their electronic structure and magnetic properties to that of the hexairon analogues
4) Preparation and characterisation of charge transfer salts of ligand-modified hexairon clusters, including neutron diffraction experiments at the Institut Laue-Langevin and the Laboratoire Léon Brillouin
5) study of ligand modifications on the nature of magnetic anisotropy in monocationic hexairon clusters

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

Supramolecular polymerisations were employed to link hexanuclear clusters exhibiting giant spin and slow magnetic relaxation. Novel coordination polymers and their constituent clusters were characterised structurally and electrochemically, and their magnetic properties were investigated by SQUID magnetometry. The charge, coordination chemistry and polymerisation behaviour was extensively explored. The project results were presented at various conferences, including the American Chemical Society Spring conference in New Orleans (March 2018), the conference Groupement de Recherches: Magnétisme et Commutation Moléculaires (November 2019), and at a number of invited talks (Harvard University Centre for the Environment - April 2019, Durham University - April 2019, and King’s College London - August 2019). Results from this project will also be disseminated in invited talks at York University UK (November 2020), the Global Inorganic Discussion Weekdays in association with the Chemical Institute of Canada (November 2020), and the Institute of Chemical Engineering Sciences, ICEHT/FORTH, Greece (November 2020).

Resulting publications from this project include Chem. Sci. 2019, 10, 6304 (Chemical Science is a gold open access journal: since 2015 there are no submission, publication or article download charges), with a number of further publications currently in preparation.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

Polymeric cluster materials synthesised in the project demonstrated the ability to precisely control magnetic properties using synthetic modifications. Investigation of the clusters by magnetometry and electrochemistry show single molecule magnet behaviour in many cases, and a multitude of charge transfer processes. By detailed investigation using neutron diffraction, we were able to obtain magnetization density maps for various iron clusters, allowing us to gain unprecedented insight into the structural features giving rise to strong magnetic exchange. As a result of these investigations, and the further understanding of the magnetic properties and electronic structures within these types of clusters, these materials may be of interest in future materials for use in charge- and data-storage.
Various areas of investigation (which are to published in due course) included:
1) coordination of bidentate ligand molecules to vacant metal sites on hexairon clusters to form coordination polymers
2) modification of the ortho-phenylenediamine ligand framework in order to shift (oxidatively and reductively) the potentials of hexairon cluster redox events
3) synthesis of a series of hexacobalt clusters, and comparison of their electronic structure and magnetic properties to that of the hexairon analogues
4) Preparation and characterisation of charge transfer salts of ligand-modified hexairon clusters, including neutron diffraction experiments at the Institut Laue-Langevin and the Laboratoire Léon Brillouin
5) study of ligand modifications on the nature of magnetic anisotropy in monocationic hexairon clusters

Synthesis of a hexanuclear [Fe6] cluster from a templating o-phenylenediamaine ligand'