Spectroscopy of europium and terbium pyridine-carboxylates

Luminescence, luminescence excitation, IR, and Raman spectra of europium and terbium isomeric pyridine-carboxylates: isonicotinates, nicotinates and picolinates were studied. The ways of the excitation energy transfer from the ligand to Ln(3+) were analysed in dependence on the structure and the type of co-ordination of ligand. Intraligand charge transfer bands and Tb3+ f-d transition bands were identified in the luminescence excitation spectra of terbium and europium compounds. Co-ordination of nitrogen atom by terbium ion in picolinates (and dipicolinates) causes low-frequency shift of the f-d bands and promotes the excitation of luminescence through d-states of Tb3+. (C) 2004 Elsevier B.V. All rights reserved.