Crystal Structure, Fluorescence, Magnetic Properties and DNA Interaction of Four Novel Binuclear LnⅢ2 Compounds with Schiff Ligand

Four new Ln2 compounds, [Ln2(H2L-)2(acac)2(CH3O)2] (Ln = Sm(1), Tb(2), Ho(3) and Er(4), H3L = 2- hydroxy-N'-[(1E)-(8- hydroxyquinolin-2-yl)methylidene]benzohydrazide), were synthesized by using a mul-tidentate Schiff ligand and lanthanide fi-diketone salts via solvent evaporation methods. The X-ray struc-tural analysis reveal that the four Ln2 compounds are dinuclear compounds and each Ln(III ) ion is eight-coordinated. The two central Ln(III ) ions are bridged by two mu 2 -O atoms from 8-hydroxyquinoline Schiff base ligands, leading to a parallelogram Ln2O2 core. The magnetism investigation shows that compound 2 display slow magnetic relaxation behavior under zero dc field (AE/kB = 19.77 K and r0 = 1.35 x 10 -6 s). Subsequent studies strongly suggested that the four Ln2 compounds binded to Calf thymus DNA (CT-DNA) through intercalative mode and have pBR322 plasmid DNA cleavage ability. This work will provide more insights for the design and investigation of lanthanide-based SMMs, and has certain reference value to study the interaction between compound and DNA.(c) 2023 Elsevier B.V. All rights reserved.