title: Anthraimidazoledione Based Reversible and Reusable Selective Chemosensors for Fluoride Ion: Naked-Eye, Colorimetric and Fluorescence "ON-OFF".
abstract: Novel anthraimidazoledione-based compounds (1-3) are synthesized as selective colorimetric and fluorescent sensors for fluoride ion. The binding properties of the probes (1-3) are studied with different anions in acetonitrile solvent. Spectral red shifts in the absorption spectra and 'turn-off' emission are observed when fluoride is added to 1-3. The striking green to orange color change in the ambient light is thought to be due to the deprotonation of the N-H proton of the imidazole moiety of the probes by the basic F-ion. Interestingly, in all three cases the nonfluorescent probe-F-solutions, on treatment with copper perchlorate, show distinct color change from orange to golden yellow with resumption of fluorescence intensity. Furthermore, the reversibility of sensors (1-3) for the detection of F-ion is tested for four cycles indicating that "ON-OFF-ON" mechanism is operative. Test strip based on sensor 2 acts as a reusable cost-effective F-sensor.
authors.affiliation: Department of Chemistry, Government Girls' General Degree College, Kolkata, -700013, India.
authors.forename: Bhaswati
authors.initials: B
authors.lastname: Bhattacharyya
authors.affiliation: Department of Chemistry, Maulana Azad College, Kolkata, -700013, India.
authors.forename: Arijit
authors.initials: A
authors.lastname: Kundu
authors.affiliation: Department of Chemistry, University College of Science & Technology, Kolkata, -700009, India. nguchhait@yahoo.com.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Guchhait
authors.affiliation: Department of Chemistry, University College of Science & Technology, Kolkata, -700009, India. chemkpd@gmail.com.
authors.forename: Kaliprasanna
authors.initials: K
authors.lastname: Dhara
keywords: Anthraimidazoledione; Colorimetry; Fluorescence; Fluoride ion; Sensor