Dysprosium-based linear helicate clusters: syntheses, structures, and magnetism†
Abstract
Three new dysprosium-based linear helicate clusters, namely, [Dy4(HL)2L(DMF)8]·2ClO4·CH2Cl2·4DMF·(CH3CH2)2O·H2O (1), [Dy6L3(PhCOO)6(CH3OH)6]·11CH3OH·H2O (2), and [Dy10Na2L4(μ3-OH)4(DMF)12(NO3)6]·6NO3·2DMF·(CH3CH2)2O·H2O (3), were assembled using the versatile pyridazine-based Schiff-base ligand H4L ([3,6-bis(2-hydroxy-3-methoxybenzylidene)hydrazinecarbonyl]-pyridazine), which displays various coordination modes depending on the reaction conditions because of the presence of tautomeric maneuver. Structural analysis indicates that compounds 1 and 2 show a tetranuclear and a hexanuclear triple-stranded helicate structure, respectively, while compound 3 with the {Dy10Na2} core has a dual double-stranded helicate structure. Besides, magnetic measurements reveal that all compounds exhibit zero-field slow relaxation behavior expected for typical SMM features.