Nitrate-Bridged “Pseudo-Double-Propeller”-Type Lanthanide(III)–Copper(II) Heterometallic Clusters: Syntheses, Structures, and Magnetic Properties

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