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 [Cu4Ln2L4L′4(NO3)2(OH2)2]·3NO3·4H2O [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 Cu2/Ln
core connected to other opposite-handed similar trimers by a bridging
nitrate ligand. The Dy analogue, [Cu4Dy2L4L′4(NO3)2(OH2)2]·3NO3·4H2O, shows frequency-dependent
out-of-phase alternating-current magnetic susceptibility, which indicates
that this novel discrete [Cu4Dy2] heterometallic
cluster may exhibit single-molecule-magnet behavior.