Syntheses, Structures, and Fluorescent Properties of ­Lanthanide Complexes Based on the Ligand Benzotriazole‐5‐carboxylic Acid

Abstract

AbstractThree lanthanide complexes with the formula [Ln(Hbtca)3(4,4′‐bpy)(H2O)2]n·nH2O [Ln = Eu (1), Gd (2), Tb (3)] (4,4′‐bpy = 4,4′‐bipyridine; H2btca = benzotriazole‐5‐carboxylic acid) were synthesized and characterized. Single‐crystal X‐ray diffraction analysis shows that complexes 1–3 possess 1D chain structures. There are O–H···N, O–H···O, and N–H···N hydrogen bonds, which result in the formation of 3D supramolecular networks. When excited at 360 nm, complexes 1 and 3 give characteristic emissions of EuIII and TbIII ions, respectively, whereas in the mixed Eu/Tb complex, EuIII emissions are strengthened and TbIII emissions are quenched, which indicates that energy may be transferred from TbIII to EuIII ions.