Estudo das propriedades fotoluminescentes de hidrocinamatos de Eu3+ e Gd3+ contendo ligantes N,N-bidentados e N,N,N-tridentado

Abstract

The study on lanthanide ions coordination compounds has become increasingly explored, due to its enormous variety of applications, be they catalytic, biological, magnetic, optical, among others. One of the main characteristics of lanthanide coordination compounds is their photoluminescent property and, thus, these compounds have enormous potential to act as Light Converting Molecular Devices (DMCLs). Therefore, the present work proposes the synthesis, structural characterization and photoluminescent study of six coordination compounds of lanthanides (Eu3+ and Gd3+) derived from hydrocinnamic acid and containing ancillary ligands, such as: 4,4'-dimethyl-2,2'-bipyridine (4,4'-dmbpy), batophenanthroline (bath) and 2,2’:6’,2’’-terpiridine (terpy). Such compounds were synthesized and properly characterized by techniques: elementary analysis (% C, H, N), infrared spectroscopy (FTIR) and X-ray diffraction using the polycrystalline method. The photophysical study of the Eu3+ complexes were obtained through excitation and emission spectra (295 and 77 K), Eu3+ lifetime of the emitting state and phosphorescence of the respective Gd3+ compounds. The energy transfer process was completely elucidated by obtaining theoretical calculations by the SPARKLE method, providing the energy transfer and back-transfer rates between the different energy levels in such compounds. Additionally, a structure-photoluminescence relationship of the studied compounds can be obtained, evidenced by the values of the parameters of the 2 and 4 experimental intensities (Judd-Ofelt parameters).