Nitrate-bridged "pseudo-double-propeller"-type lanthanide(III)-copper(II) heterometallic clusters: Syntheses, structures, and magnetic properties

Abstract

Two discrete nitrate-bridged novel "pseudo-double-propeller"- shaped hexanuclear Cu/Ln clusters of the formula [Cu 4Ln 2L 4L′ 4(NO 3) 2(OH 2) 2]·3NO 3·4H 2O [Ln = Dy, Gd; LH = o-vanilin; L′H = 2-(hydroxyethyl) pyridine] were synthesized and characterized. Single-crystal X-ray diffraction studies revealed the trimeric half-propeller-type Cu 2/Ln core connected to other opposite-handed similar trimers by a bridging nitrate ligand. The Dy analogue, [Cu 4Dy 2L 4L′ 4(NO 3) 2(OH 2) 2] ·3NO 3·4H 2O, shows frequency-dependent out-of-phase alternating-current magnetic susceptibility, which indicates that this novel discrete [Cu 4Dy 2] heterometallic cluster may exhibit single-molecule-magnet behavior. © 2012 American Chemical Society.