On the Fluorescent, Steric and Electronic Factors Affecting the Detection of Metallic Ions Using an Imidazolyl-Phenolic Derived Fluorescent Probe

Autor(es)

Orfao, Jr., Ronaldo B. ^[1] ; de Carvalho, Fabricio ^[1] ; Homem-de-Mello, Paula ^[1] ; Bartoloni, Fernando H. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 28, n. 10, p. 1896-1904, OCT 2017.
• Citações Web of Science: 4

Resumo

The imidazolyl-phenolic probe used at the present study has its photophysic properties regulated by a tautomeric equilibrium. After the absorption of a photon, an excited state intramolecular proton transfer process generates a ketonic species, responsible for the 440 nm emission (in CH3CN/H2O, 95:5, v/v). Addition of Cu2+, Al3+, Cr3+ and Fe3+ suppresses emission through a combination of dynamic and static-like quenching, as indicated by Stern-Volmer plots, with a higher sensitivity for Cu2+ (KSV = 1.90 × 105 and 2.40 × 104 L mol-1, respectively, for Cu2+ and Fe3+). The trivalent ions led to the formation of a locked-enol tautomer that emits at shorter wavelengths; this coordinated compound is also quenched at metallic ions concentrations above 20 µmol L-1, due to a collisional process. When compared to another imidazolyl-phenolic probe, experimental and simulated data revealed that fluorescent, steric and electronic effects regulate their sensitivity towards the ions. (AU)

• Processo FAPESP: 14/05813-2 - Aplicação de fluoróforos contendo grupos fenólicos e nitrogenados na detecção de metais por emissão de luz
• Beneficiário: Ronaldo Barros Orfão Junior
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 12/13807-7 - Novas ferramentas para o estudo de reações de transferência de elétron em sistemas modelo do PS II
• Beneficiário: Fernando Heering Bartoloni
• Modalidade de apoio: Auxílio à Pesquisa - Regular