A new photoluminescent terbium(III) coordination network constructed from 1,2,4,5-benzenetetracarboxylic acid: Synthesis, structural characterization and application as a potential marker for gunshot residues

• Published in: Inorganica Chimica Acta 2019-09, Vol.495, p.118967, Article 118967
• Main Authors: Silva, Mariane A., de Campos, Nathália R., Ferreira, Leonildo A., Flores, Leonã S., Júnior, Júlio C.A., dos Santos, Guilherme L., Corrêa, Charlane C., dos Santos, Thiago C., Ronconi, Célia M., Colaço, Marcos V., Simões, Tatiana R.G., Marques, Lippy F., Marinho, Maria Vanda
• Format: Article
• Language: English
• Subjects: Chelation; Construction; Coordination; Crime; Crystal structure; Emission analysis; Firearm discharge residue; Gunshot residues; Hydrothermal synthesis; Ligands; Luminescence emission; Markers; Optical properties; Photoluminescence; Residues; Single crystal X-ray diffraction; Single crystals; Stability analysis; Structural analysis; Terbium; Terbium(III) ion; Thermal stability; Thermogravimetric analysis; Topology
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2019.118967

We present a highly photoluminescent and thermally stable terbium(III) coordination network [TbHbtec]n CN 1, exhibiting a cubic primitive network with topology pcu-αPo, uninodal and point symbol (412. 63). The results show that CN 1 is a good candidate for luminescent marker of gunshot residues (GSR). [Display omitted] •New TbIII-coordination network with topology pcu-αPo uninodal and point symbol (412. 63).•3-D coordination network of formula [TbHbtec]n, [H4btec = 1,2,4,5-benzenetetracarboxylic acid].•High thermal stability (higher than 470 °C) and high photoluminescence.•Good candidate as luminescent marker for gunshot residues.•Stability of the structure after exposure to high temperature of detonation. A novel terbium(III) coordination network (CN) of formula [TbHbtec]n1, constructed from 1,2,4,5-benzenetetracarboxylic acid (H4Btec) and Tb3+ ions, has been obtained under hydrothermal conditions. Single crystal X-ray diffraction and topological studies revealed the crystal structure of CN 1 involves a cubic primitive network with topology pcu-αPo, uninodal and with point symbol (412. 63). In the crystal structure, the ligand is monoprotonated (Hbtec3−) with six Hbtec3− adopting the monodentate, bidentate chelating and bidentate chelating-bridging coordination modes, leading to the formation of a 3-D coordination network. Solid state luminescence spectrum showed the characteristic 5D4 → 7FJ (J = 6–2) transitions of the Tb3+ ion upon excitation in the Hbtec3− singlet levels, revealing that the ligand Hbtec3− is a good sensitizer for the intense green emission of Tb3+ ions. Thermogravimetric analysis (TGA) showed CN 1 has exceptional thermal stability decomposing at temperatures higher than 470 °C. Taking advantage of its excellent thermal and optical properties, the [TbHbtec]n was tested as luminescent marker for gunshot residues, opening the possibility of using this compound in forensic analysis of crime scenes.