N3O6versus N2O6 coordinated dysprosium slow magnetic relaxation in a tetrathiafulvalene-based dinuclear complex.

The Dy2 dinuclear complex behaves as a multi-field-induced Single-Molecule Magnet in which the two Ising Dy(III) ions display distinct relaxation times of their magnetization due to different magnetic relaxation processes. The reaction between the 2-(1-(4′-[4-(methylphenyl]-2,2:6′,2″-terpyridyl)-4,5-(4,5-bis(propylthio)-tetrathiafulvalenyl)-1H-benzimidazol-2-yl)-pyridine (L) and 2 equivalents of Dy(hfac) 3 ·2H 2 O (hfac− = 1,1,1,5,5,5-hexafluoroacetyacetonate) metallic precursors leads to the formation of a dinuclear complex of formula [Dy 2 (hfac) 6 (L)]·C 6 H 14 (Dy2). The X-ray structure on single crystal reveals the occupation of the two benzoimidazolylpyridine (bzip) and terpyridyl (terpy) coordination sites with a Dy(III) ion. The two D 4d and C 4v Dy(III) ions highlighted slow magnetic relaxation under an applied magnetic field. Even if the two lanthanide centers have similar magnetic anisotropy, they displayed different relaxation times of their magnetization which could be explained by the distinct nature of the magnetic relaxation processes. These conclusions are supported by ab initio calculations. [ABSTRACT FROM AUTHOR]