Heterocyclic imidazo-anthraquinone as an optical sensor: synthesis, characterization and evaluation of the chemosensory ability

A novel imidazo-anthraquinone derivative 3 was synthesized in moderate yield. The photophysical properties of the new compound were studied by UV-vis and fluorescence spectroscopy in ACN. The evaluation of the new compound as a colorimetric chemosensor was carried out by performing spectrophotometric titrations in ACN and ACN/H2O in the presence of relevant organic and inorganic anions and transition metal cations. Imidazo-anthraquinone 3 exhibited great selectivity for the cyanide anion over other anions in ACN/H2O (95:5) solution showing a distinct color change from yellow to pink.Fundação para a Ciência e Tecnologia (Portugal) and FEDER-COMPETE for financial support through Centro de Química (UID/QUI/00686/2013 and UID/ QUI/0686/2016), and a PhD grant to R.C.M. Ferreira (SFRH/BD/86408/2012). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased with funds from FCT and FEDER