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Orientador(es)
Resumo(s)
A new topological design of fluorescent probes for sensing copper ion is disclosed.
The calix[4]arene-oxacyclophane (Calix-OCP) receptor, either wired-in-series in arylene-alt-ethynylene conjugated polymers or standing alone as a sole molecular probe, display a remarkable a_nity and selectivity for Cu(II). The unique recognition properties of Calix-OCP system toward copper cation stem from its pre-organised cyclic array of O-ligands at the calixarene narrow rim, which is kept in a conformational rigid arrangement by a tethered oxacyclophane sub-unit. The magnitude of the binding constants (Ka = 5.30 8.52 _ 104 M1) and the free energy changes for the inclusion complexation (DG = 27.0 28.1 kJmol1), retrieved from fluorimetric titration experiments, revealed a high sensitivity of Calix-OCP architectures for Cu(II) species. Formation of supramolecular inclusion complexes was evidenced from UV-Vis spectroscopy. The new Calix-OCP-conjugated polymers (polymers 4 and 5), synthesized in good yields by Sonogashira–Hagihara methodologies, exhibit high
fluorescence quantum yields (_F = 0.59 0.65). Density functional theory (DFT) calculations were used to support the experimental findings. The fluorescence on–o_ behaviour of the sensing systems is tentatively explained by a photoinduced electron transfer mechanism.
Descrição
Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2016 do Instituto Politécnico de Lisboa. Código de referência IPL/2016/NoSeMeTox_ISEL
Palavras-chave
calix[4]arene copper supramolecular inclusion complex fluorescence sensor density functional theory
Contexto Educativo
Citação
COSTA, Alexandra I.; [et al] – Highly sensitive and selective fluorescent probes for Cu(II) detection based on calix[4]arene-oxacyclophane architectures. Molecules. ISSN 1420-3049. Vol. 25, N.º 10 (2020), pp. 1-17
Editora
MDPI