Terbium(III) complex with 2,2'-Bipyrimidine as a Luminescent Probe for the Detection of Metal Ions in Aqueous Solution

• Grant number: 25/15569-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2025
• End date: November 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Airton Germano Bispo Júnior
• Grantee: Ricardo Queiroz Carneiro
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/08111-2 - Development of rare earth based light converters: luminescent markers, optical sensors, and amplifiers, AP.TEM

Abstract

The luminescence of trivalent lanthanide ions (LnIII) has attracted considerable interest in the development of optical and selective sensors for the detection of metallic ions in solution. It is important to detect these metallic ions in solution because they can control metabolic processes while there is an ecological interest in the monitoring of contaminants. This project proposes the synthesis and characterization of the luminescent complex [Tb(acac)3(bpm)], (acac = acetylacetone, bpm = 2,2'-bipyridine) aiming to use it as a luminescent probe to determine the concentration of metallic ions in solution. In this complex, TbIII is coordinated to three acac ligands and one bpm, both bidentate. The structure of the complex predicts a free coordination site in the bpm ligand, capable of interacting with metallic ions. This interaction can modulate the energy transfer between the ligand and the emitter center, resulting in suppression effects ("turn-off") or intensification ("turn-on") of luminescence. The proposal targets to explore these changes as analytical signal for the quantification of environmentally and/or biologically relevant ions, such as PbII, AlIII, ZnII, CuII, FeIII, CoII and NiII. The strategy includes the construction of analytical curves based on the emission intensity or TbIII 5D4 emitting state lifetime. In conclusion, the project incorporates aspects of synthesis, structural characterization and analytical application, promoting interdisciplinary formation and contributes to the development of accessible methodologies for chemical monitoring in aqueous solution. (AU)