title: A New Fluorescent "Turn-Off" Coumarin-Based Chemosensor: Synthesis, Structure and Cu-Selective Fluorescent Sensing in Water Samples.
abstract: We report the synthesis and characterization two coumarin-based fluorescence probes, N'-{[7-(diethylamino)-2-oxo-2H-chromen-3-yl]carbonyl}pyridine-3-carbohydrazide (3) and N'-benzoyl-7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide (4), proposed as a novel fluorescent chemosensor. The two probes designed showed an instant turn-off fluorescence response to Cu2+over other metal ions in ethanol-water mixture based on intramolecular charge transfer (ICT). It was found that pyridine-analogue coumarin is highly selective and sensitive sensor for Cu2+. The 3 sensor coordinates Cu2+in 1:1 stoichiometry with a binding constant, Ka= 5.22 M-1and the detection limit was calculated 1.97 × 10-9M.
authors.affiliation: Vocational School of Technical Studies, Department of Chemistry and Chemical Processing Technology, Recep Tayyip Erdogan University, Rize, Turkey. kaan.karaoglu@erdogan.edu.tr.
authors.forename: Kaan
authors.identifier: http://orcid.org/0000-0003-3265-8328
authors.initials: K
authors.lastname: Karaoglu
authors.affiliation: Faculty of Arts and Sciences, Department of Chemistry, Recep Tayyip Erdogan University, Rize, Turkey.
authors.forename: Fatih
authors.initials: F
authors.lastname: Yilmaz
authors.affiliation: Faculty of Arts and Sciences, Department of Chemistry, Recep Tayyip Erdogan University, Rize, Turkey.
authors.forename: Emre
authors.initials: E
authors.lastname: Menteşe
keywords: Copper (II) sensor; Coumarin; Fluorescence; ICT