Syntheses, crystal structures, and luminescence properties of lanthanide complexes with 5-carboxy-1-carboxymethyl-2-oxidopyridinium

Five new lanthanide complexes Ln(HL)3(H2O)5 · 3H2O (H2L = 5-carboxy-1-carboxymethyl-2-oxidopyridinium, Ln = La (1), Sm (2), Eu (3),Tb (4), Dy (5)) have been synthesized and characterized by elemental analyses, FT-IR spectra and X-ray single crystal diffraction. All crystals are isostructural and crystallize in the triclinic space group P1¯. The metal center is nine-coordinated completely by two phenol O atoms, two chelating carboxylic O atoms from three HL ligands and five water molecules with a distorted tri-capped trigonal prismatic geometry. Photoluminescence studies revealed that complexes 2–4 exhibit strong fluorescent emission bands in the solid state at room temperature. The transition intensity varies in the order of Tb3+ > Dy3+ > Eu3+ > Sm3+.

Graphical abstractFive new lanthanide complexes Ln(HL)3(H2O)5 · 3H2O (H2L = 5-carboxy-1-carboxymethyl-2-oxidopyridinium, Ln = La (1), Sm (2), Eu (3),Tb (4), Dy (5)) have been synthesized and characterized by elemental analyses, FT-IR spectra and X-ray single crystal diffraction. The photoluminescence properties were also studied.Figure optionsDownload full-size imageDownload as PowerPoint slide