Syntheses, Structures, Photoluminescence, and Magnetism of a Series of Discrete Lanthanide Complexes based on 2,5-Dichlorobenzoate and 1,10-Phenanthroline

The syntheses and crystal structures of eight lanthanide complexes with formula [Ln(2,5-DCB)(x)(phen)(y)] are reported, which are characterized via single-crystal, powder X-ray diffraction, elemental analysis, IR spectroscopy, thermogravimetric analysis, photoluminescence measurement, and DC/AC magnetic measurement. These eight complexes are isostructural, and possess a discrete dinuclear structure. The adjacent dinuclear molecules are linked by the hydrogen bonding interactions into a one-dimensional (1D) supramolecular chain. The neighboring 1D chains are further extended into a two-dimensional (2D) supramolecular layer by the pi-pi stacking interactions. The photoluminescent properties of complexes 1 (Nd-III), 2 (Sm-III), 3 (Eu-III), 5 (Tb-III), 6 (Dy-III), and 8 (Yb-III) were investigated. Magnetic investigations also reveal the presence of ferromagnetic interactions in complexes 4 (Gd-III), 6 (Dy-III), and 7 (Er-III). Additionally, complex 6 (Dy-III) demonstrates field-induced slow magnetic relaxation behavior.