Fabrication and photophysical property of Tb(III), Dy(III) and Eu(III) complex LB films containing double functional ligand of long chain mono docosyl phthalate

Abstract

In this paper, new novel long chain amphiphillic monoester molecules were designed to afford double functions: film-formation and luminescent sensitization. Subsequently, organized molecular films of rare earth complexes with the functional ligands formulated as ML 2NO 3 were fabricated by the Langmuir–Blodgett film (LB) technology, where M denotes rare earth ions Eu 3+, Tb 3+ and Dy 3+; L denotes the long chain carboxylic ligands monodocosyl phthalate (22-Phth). The average molecular area was obtained according to the π-A isotherms. The LB film layer structure was demonstrated by low-angle X-ray diffraction and the average layer spacing were obtained according to the Bragg equation. UV absorbance intensity increases linearly with the number of LB films layers, which indicate that the LB films are homogeneously deposited. The fluorescence spectra of these LB films were quite different from those of their corresponding solid complexes. It reveals that the long chain esters ligands are suitable for those of the excited states of the luminescent Tb 3+ ion and Dy 3+ ion in the LB films as well as in the solid complexes, but not sensitize the europium ion effectively in the LB films.