Magnetic properties and structure of tetranuclear lanthanide complexes based on 8-hydroxylquinoline Schiff base derivative and β-diketone coligandElectronic supplementary information (ESI) available: The important bond lengths [Å] and angles [°], TGA spectra and PXRD patterns of complexes 1-5; DyIII geometry analysis and Cole-Cole plots for 3; and temperature dependencies of the magnetic entropy change of 1. CCDC 1491600, 1491601, 1491599, 1491615 and 1491614. For ESI and crystallographic data i

Five tetranuclear lanthanide complexes [Gd 4 (dbm) 4 (L) 6 (μ 3 -OH) 2 ]·5CH 3 CN ( 1 ), [Tb 4 (dbm) 4 (L) 6 (μ 3 -OH) 2 ]·2CH 3 CH 2 OH·4CH 3 CN ( 2 ), [Dy 4 (dbm) 4 (L) 6 (μ 3 -OH) 2 ]·4CH 3 CN·2H 2 O ( 3 ), [Ho 4 (dbm) 4 (L) 6 (μ 3 -OH) 2 ]·CH 3 CH 2 OH·4CH 3 CN·2H 2 O ( 4 ) and [Er 4 (dbm) 4 (L) 6 (μ 3 -OH) 2 ] ( 5 ) are obtained from the reaction of 5-(4-pyridinecarboxaldehyde)amino-8-hydroxylquinoline (HL) and Ln(dbm) 3 ·2H 2 O (dbm = 1,3-diphenyl-1,3-propanedione). Complexes 1-5 are isomorphous and crystallize in the monoclinic space group P 2 1 / c . The metal ions in 1-5 adopt an approximately square-antiprismatic coordination environment. Magnetic studies indicate that complex 1 features a magnetocaloric effect (MCE) with the magnetic entropy change of −Δ S m ( T ) = 16.35 J kg −1 K −1 at 3 K for Δ H = 7 T. Additionally, complex 3 displays single molecule magnet (SMM) behavior, exhibiting an effective energy barrier of the relaxation of magnetization U eff / k B = 89.38 K and pre-exponential factor τ 0 = 3.32 × 10 −8 s. Herein, we report the synthesis, structure, and magnetism of five tetranuclear Ln III complexes encapsulated by 5-(4-pyridinecarboxaldehyde)amino-8-hydroxylquinoline and β-diketonate coligand.