Novos β-dicetonatos de Eu3+ e Gd3+ para aplicação como marcadores luminescentes em munições em armas de fogo: um auxílio para a segurança pública do Estado do Rio de Janeiro

Abstract

Lanthanide coordination compounds (Ln) have been the subject of several research projects in recent decades, mainly in the quest to construct multifunctional inorganic materials with diverse physicochemical properties and strategic functions. Numerous studies by the scientific community are proposed with Ln complexes containing organic ligands, due to the extreme ease of these ligands associating with metallic centers and the interesting luminescent properties that such compounds possess. In this context, lanthanide β-diketonates have all the characteristics required to act as molecular light-converting devices (DMCLs), with application in different areas. Therefore, the present work proposes the synthesis, structural characterization and photophysical study of eight (8) new tris-diketonated lanthanide coordination compounds (Eu3+ and Gd3+), containing the β-diketones 4,4,4-trifluoro-1 -(2-thenoyl)-1,3-butanedione (Htta) and 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbtfa). Along with these β-diketone ligands, the auxiliary ligands 2-piperidinone (δ-valerolactam or δ-val) and 2-oxohexamethyleneimine (ε-caprolactam or ε-cap) were used, which belong to the lactam class. Several spectroscopic and analytical techniques were used to characterize and study the properties of these complexes, such as: elemental analysis (%CHN), thermal analysis (TG/DTG), vibrational spectroscopy in the infrared region (FTIR), X-ray diffraction by polycrystals (DRXP) and photoluminescence spectroscopy (PL). Additionally, some of the synthesized compounds were used as luminescent markers in firearm ammunition, proving to be very effective in the forensic tests carried out, opening a perspective for the unprecedented use of lanthanide β-diketonates for this purpose.