Lanthanide Complexes with 4,4′-Bis(2-sulfonatostyryl)-biphenyl: Crystal Structures and Luminescence Properties

Abstract

A series of new tris(pyrazolyl)borate (Tp−) and tris(2-pyridylpyrazolyl)borate (TpPy−) Eu3+, Gd3+, Tb3+ and Dy3+ complexes with the dianionic ligand 4,4′-bis(2-sulfonatostyryl)biphenyl (Ssp2−, a widely used fluorescent whitener) were synthesized and their luminescence properties were studied. The Gd3+, Tb3+ and Dy3+ compounds possess only ligand-centered emission, arising from the Ssp2− ligand, with quantum yields of up to 60 %. While the emission centers in these complexes are similar, the positions of the luminescence maxima, the emission quantum yields, and the lifetimes change in the order [(Tp2Ln)2Ssp]