A Supramolecular Aggregate of Four Exchange-Biased Single-Molecule Magnets

Tu N. Nguyen , Wolfgang Wernsdorfer (1) , Khalil A. Abboud , George Christou (2)

1 NEEL - QuantECA - Circuits électroniques quantiques Alpes
2 UF|Chemistry - Department of Chemistry [Gainesville]

The reaction between 3-phenyl-1,5-bis(pyridin-2-yl)pentane-1,5-dione dioxime (pdpdH(2)) and triangular [Mn(3)(III)O(O(2)CMe)(py)(3)](ClO(4)) (1) affords [Mn(12)O(4)(O(2)CMe)(12)(pdpd)(6))](ClO(4))(4) (3). Complex 3 has a rectangular shape and consists of four [Mn(3)(III)O](7+) triangular units linked covalently by the dioximate ligands into a supramolecular [Mn(3)](4) tetramer. Solid-state dc and ac magnetic susceptibility measurements revealed that [Mn(3)](4) contains four Mn(3) single-molecule magnets (SMMs), each with an S = 6 ground state. Magnetization versus dc-field sweeps on a single crystal gave hysteresis loops below 1 K that exhibited exchange-biased quantum tunneling of magnetization steps, confirming 3 to be a supramolecular aggregate of four weakly exchange-coupled SMM units

Domaines: Physique [physics]

Tu N. Nguyen, Wolfgang Wernsdorfer, Khalil A. Abboud, George Christou. A Supramolecular Aggregate of Four Exchange-Biased Single-Molecule Magnets. Journal of the American Chemical Society, 2011, 133 (51), pp.20688-20691. ⟨10.1021/ja2087344⟩. ⟨hal-00979288⟩