Chiral supramolecular nanotubes of single-chain magnets

Felix Houard (1) , Quentin Evrard (1) , Guillaume Calvez (1) , Yan Suffren (1) , Carole Daiguebonne (1) , Olivier Guillou (1) , Frederic Gendron (1) , Boris Le Guennic (1) , Thierry Guizouarn (1) , Vincent Dorcet (1) , Matteo Mannini (2) , Kevin Bernot (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 UniFI - Università degli Studi di Firenze = University of Florence

We report a Single-Chain Magnet (SCM) made of a Terbium(III) building block and a nitronyl-nitroxide radical (NIT) functionalized with an aliphatic chain. This substitution is targeted to induce a long range distortion of the polymeric chain and accordingly it gives rise to chains that are curled with almost 20 nm helical pitch. They self-organize as a chiral tubular superstructure made of 11 chains wound around each other. The supramolecular tubes have a 4.5 nm internal diameter. Overall, this forms a porous chiral network with almost 44% porosity. Ab-initio calculations highlight that each Tb III ion possesses high magnetic anisotropy. Indeed, notwithstanding the supramolecular arrangement each chain behaves as a SCM. Magnetic relaxation with both finite and infinite-size regimes is observed and confirms the validity of the Ising approximation. This is associated with quite strong coercive field and magnetic remanence (Hc = 2400 Oe MR = 2.09 µB at 0.5 K) for this class of compounds.

Keywords: Supramolecular; Lanthanides; Radicals; Single-Chain Magnets; Nanotubes; chirality

Domains: Chemical Sciences

Felix Houard, Quentin Evrard, Guillaume Calvez, Yan Suffren, Carole Daiguebonne, et al.. Chiral supramolecular nanotubes of single-chain magnets. Angewandte Chemie International Edition, 2020, 59 (2), pp.780-784. ⟨10.1002/anie.201913019⟩. ⟨hal-02364864⟩