A Purely Lanthanide-Based Complex Exhibiting Ferromagnetic Coupling and Slow Magnetic Relaxation Behavior

Two lanthanide−organic frameworks, {Ln(TDA)1.5(H2O)2}n [TDA = thiophene-2,5-dicarboxylic acid anion; Ln = Gd (1), Dy (2)], were structurally and magnetically characterized. The magnetic studies revealed that the ferromagnetic coupling existed between adjacent lanthanide ions in 1 and 2, and only 2 displays slow magnetic relaxation behavior with τ0 = 2.4 × 10−8 s and ΔE/kB = 44.2 K. To our knowledge, it is rather rare that ferromagnetic coupling and slow magnetic relaxation coexist in three-dimensional lanthanide-based frameworks.