Eu(III), Tb(III) complexes with novel ligands containing pyridine-2,6-dicarboxylic acid unit: Synthesis, characterization, fluorescence properties and application in biological imaging

Three novel ligands containing pyridine-2,6-dicarboxylic acid unit, trans-4 -(4′-methoxystyryl) pyridine-2,6-dicarboxylic acid, trans-4-(4′-(dimethylamino)styryl)pyridine-2,6-dicarboxylic acid, and trans-4-(4′-(diphenylamino)styryl)pyridine-2,6-dicarboxylic acid were synthesized and their complexes with Eu(III), Tb(III) ions were successfully prepared. The ligands and the corresponding metal complexes were characterized by means of MS, elemental analysis, IR, 1H NMR and TG–DTA. The luminescence spectra of Eu(III) and Tb(III) complexes in solid state were studied. The strong luminescence emitting peaks at 615 nm for Eu(III) and 545 nm for Tb(III) can be observed. The applications in cell imaging of the europium and terbium complexes were investigated.

Graphical abstract.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Eu(III), Tb(III) complexes with novel ligands were synthesized. ► The coordination numbers of Eu(III) and Tb(III) ions is nine. ► The characteristic luminescence of europium and terbium ions can be observed. ► The europium and terbium complexes were applied in cell imaging.