title: A supramolecular aggregate of four exchange-biased single-molecule magnets.
abstract: The reaction between 3-phenyl-1,5-bis(pyridin-2-yl)pentane-1,5-dione dioxime (pdpdH(2)) and triangular [Mn(III)(3)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(III)(3)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.
authors.affiliation: Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
authors.forename: Tu N
authors.initials: TN
authors.lastname: Nguyen
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wernsdorfer
authors.forename: Khalil A
authors.initials: KA
authors.lastname: Abboud
authors.forename: George
authors.initials: G
authors.lastname: Christou