SciELO - Scientific Electronic Library Online

vol.23 issue8Currently used pesticides in water matrices in Central-Western BrazilComparison of the n-alkanes and polycyclic aromatic hydrocarbons concentrations in the atmosphere during the preparation of warm and hot mixtures asphalt for pavements author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Journal of the Brazilian Chemical Society

Print version ISSN 0103-5053


NICOLETI, Celso R.; MARINI, Vanderléia G.; ZIMMERMANN, Lizandra M.  and  MACHADO, Vanderlei G.. Anionic chromogenic chemosensors highly selective for fluoride or cyanide based on 4-(4-Nitrobenzylideneamine)phenol. J. Braz. Chem. Soc. [online]. 2012, vol.23, n.8, pp.1488-1500.  Epub Aug 07, 2012. ISSN 0103-5053.

4-(4-Nitrobenzylideneamine)phenol was used in two strategies allowing the highly selective detection of F- and CN-. Firstly, the compound in acetonitrile acts as a chromogenic chemosensor based on the idea that more basic anions cause its deprotonation (colorless solution), generating a colored solution containing phenolate. The discrimination of CN- over F- was obtained by adding 1.4% water to acetonitrile: water preferentially solvates F-, leaving the CN- free to deprotonate the compound. Another strategy involved an assay comprised of the competition between phenolate dye and the analyte for calix[4]pyrrole in acetonitrile, a receptor highly selective for F-. Phenolate and calix[4]pyrrole form a hydrogen-bonded complex, which changes the color of the medium. On the addition of various anions, only F- was able to restore the original color corresponding to phenolate in solution due to the fact that the anion dislodges phenolate from the complexation site.

Keywords : anionic chromogenic chemosensor; displacement assay; naked-eye detection; anion sensing; calix[4]pyrrole.

        · abstract in Portuguese     · text in English     · English ( pdf epdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License