Lanthanide complexes with a biphosphonate ester ligand and their fluorescent properties

• Lanthanide complexes with a bi-phosphonate ligand have been synthesized.
• The complexes are in three types: interwoven, linear, and ladder polymers.
• The Sm3 +, Eu3 + and Dy3 + complexes displayed the lanthanide characteristic spectrum.
• The Tb3 + complex exhibited a strong fluorescence by excitation of 300 nm.

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 Sm3 +, Eu3 +, Tb3 + and Dy3 + complexes were investigated. The Sm3 +, Eu3 + and Dy3 + complexes displayed the characteristic spectrum of the lanthanide ions. The Tb3 + 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.

Lanthanide complexes with a bi-phosphonate ligand of three different coordination networks (zigzag chain interwoven, linear and ladder) have been synthesized. Their luminescence properties were also investigated.Figure optionsDownload as PowerPoint slide