Lanthanide complexes with a biphosphonate ester ligand and their fluorescent properties

Abstract A bi-phosphonate ligand 4,4′-bis(diethylphosphonomethyl)biphenyl has been designed and synthesized. The ligand reacted with lanthanide nitrates forming three different types of coordination complexes: interwoven net polymer (type I), linear polymer (type II), and ladder polymer (type III). The photophysical properties of Sm 3 + , Eu 3 + , Tb 3 + and Dy 3 + complexes were investigated. The Sm 3 + , Eu 3 + and Dy 3 + complexes displayed the characteristic spectrum of the lanthanide ions. The Tb 3 + complex exhibited a prominent strong fluorescence by excitation of 300 nm, which indicated that there may be a luminescence sensitization effect of the complex via excitation of the ligand.