A water-soluble bithiophene with increased photoluminescence efficiency and metal recognition ability. Issue 35 (25th August 2020)

• Record Type: Journal Article
• Authors: Delgado-Pinar, Estefanía; Pineiro, Marta; Sérgio Seixas de Melo, J.
• Is Part Of: Dalton transactions. Volume 49:Issue 35(2020)
• Page Start: 12319
• Page End: 12326
• Publication Date: 2020-08-25
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt01385d
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : A water soluble and highly fluorescent bithiophene was obtained. The excited state behavior is fully characterized and with tert -butylsulfonamide derivatization the recognition of Cu(ii ) and Hg(ii ) with high selectivity was observed. Abstract : A new water-soluble tri- tert -butyl-bithiophenesulfonamide (α2-tbS ) was synthesized and a comprehensive spectroscopic and photophysical study was undertaken in organic solvents and water at different pH values. In contrast to the behaviour found for the parent (and un-substituted) α, α′-bithiophene (α2 ), in which radiationless decay processes are the main excited-state deactivation channels, the tert -butylsulfonamide derivative presents a significant fluorescence quantum yield ( ϕ F ) ( ca. one order of magnitude higher than that of α2 ). The high ϕ F allowed further exploring α2-tbS as a selective fluorimetric sensor for metal ions. A strong selectivity towards Cu(ii ) is observed at neutral pH values, whereas at pH = 9.5 a strong quenching upon the addition of Hg(ii ) is observed. An additional high sensitivity of 0.64 ± 0.02 ppm towards Cu(ii ) was observed, well below 1.25 ppm (∼20 μM), the maximum value allowed in drinking water by the EPA.