ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Photophysical Properties of Quaternary Lanthanide Molecular Functional Complex Systems

B. Yan and Q. Y. Xie

Department of Chemistry, Tongji University, Shanghai 200092, P. R. China

E-mail: byan@tongji.edu.cn

Received: 30 June 2003

Abstract: According to the molecular fragment principle, a series of twelve quaternary luminescent lanthanide complex molecular systems were assembled. Their compositions were determined using elemental analyses and infrared spectra: Ln(inic)₃(L) · H₂O, where Ln = Sm, Eu, Tb, Dy; Hinic = pyridine-4-carboxylic acid; L = N,N-dimethylformamide, N,N-dimethylacetamide, 2-pyrrolidone. The photophysical properties of these functional molecular systems were studied using ultravioletvisible absorption spectra, fluorescence excitation and emission, and phosphorescence spectra. It was found that the conjugated Hinic acts as the main energy donor and luminescence sensitizer for the suitable energy match and effective energy transfer to the luminescent Ln³⁺ ions. Amide molecules (L) were used only as the assistant structural ligands to influence the luminescence. Especially the luminescent property of terbium species is the strongest for the optimum energy transfer between the triplet of Hinic and Tb³⁺. The luminescence intensities of europium and dysprosium species were weaker than those of Tb³⁺ ones and the samarium species were the least for that there exist some internal energy levels of ⁶F_11/2, ⁶F_9/2,. . .,⁶H_11/2 between the first excited state ⁴G_5/2 and the ground state ⁶H_9/2 for Sm³⁺ ion, so the nonradiative energy transfer processes dissipate the energy greatly.

Full paper in Portable Document Format: 585a316.pdf

Chemical Papers 58 (5) 316–319 (2004)