EXPLORING THE BEHAVIOUR OF SIX DIFFERENT DANSYL-BASED DYES AS ACTIVE MOLECULAR TOOLS

• Autor(a) principal: Pedro, Gonçalo Filipe Carro
• Data de Publicação: 2024
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/162388
• topic: Spectroscopy; Luminescence Probes; Dansyl-derivatives; Acid; PMMA Doped Films; Heavy Metals; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Following the vast array of applications and great optical properties of the dansyl fluorophore, six novel dansyl-based compounds L1 to L6 have been synthesized and fully characterized in solution, solid-state and supported in a PMMA polymer matrix with the aim of discovering new luminescent sensing systems for environmental pollutants. Within this study, we present an in-depth analysis of the photophysical properties of L1 to L6 in five different solvents, revealing their distinctive positive solvatochromic behavior. We also explore their acid-base sensing capabilities in both a CH3CN solution and within a PMMA polymer matrix. Remarkably, these compounds exhibit an on-off emission response to highly acidic solutions and demonstrate excellent reversibility when exposed to ammonia. The metal sensing behaviour was examined in CH3CN solution with all compounds showing notable sensibility for Hg2+ and Cu2+ ions, and one compound also showing sensibility for Ag+ ions. The increase in concentration of metal ions was found to induce variations in absorption spectra and substantial fluorescence emission quenching. Furthermore, in anion sensing studies, compounds L4 to L6 displayed exceptional sensibility for CN and F- ions as evidenced by spectral changes and emission quenching during spectrophotometric and spectrofluorimetric titrations. In the modern days of chemistry, the search for novel luminescent sensors has gained significant momentum due to the advantages they offer over conventional methods. The present study introduces an innovative system with a wide range of potential applications in the field of environmental monitoring, enabling the detection of various pollutants and toxic agents.