title: Isatinphenylsemicarbazones as efficient colorimetric sensors for fluoride and acetate anions - anions induce tautomerism.
abstract: The anion induced tautomerism of isatin-3-4-phenyl(semicarbazone) derivatives is studied herein. The interaction of F(-), AcO(-), H2PO4(-), Br(-) or HSO4(-) anions with E and Z isomers of isatin-3-4-phenyl(semicarbazone) and N-methylisatin-3-4-phenyl(semicarbazone) as sensors influences the tautomeric equilibrium of these sensors in the liquid phase. This tautomeric equilibrium is affected by (1) the inter- and intra-molecular interactions' modulation of isatinphenylsemicarbazone molecules due to the anion induced change in the solvation shell of receptor molecules and (2) the sensor-anion interaction with the urea hydrogens. The acid-base properties of anions and the difference in sensor structure influence the equilibrium ratio of the individual tautomeric forms. Here, the tautomeric equilibrium changes were indicated by "naked-eye" experiment, UV-VIS spectral and (1)H NMR titration, resulting in confirmation that appropriate selection of experimental conditions leads to a high degree of sensor selectivity for some investigated anions. Sensors' E and Z isomers differ in sensitivity, selectivity and sensing mechanism. Detection of F(-) or CH3COO(-) anions at high weakly basic anions' excess is possible.
authors.affiliation: Institute of Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina CH-2, SK-842 15 Bratislava, Slovakia.
authors.forename: Klaudia
authors.initials: K
authors.lastname: Jakusová
authors.affiliation: Institute of Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina CH-2, SK-842 15 Bratislava, Slovakia.
authors.forename: Jana
authors.initials: J
authors.lastname: Donovalová
authors.affiliation: Institute of Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina CH-2, SK-842 15 Bratislava, Slovakia. Electronic address: cigan@fns.uniba.sk.
authors.forename: Marek
authors.initials: M
authors.lastname: Cigáň
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Comenius University, Odbojárov 10, SK-832 32 Bratislava, Slovakia.
authors.forename: Martin
authors.initials: M
authors.lastname: Gáplovský
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Comenius University, Odbojárov 10, SK-832 32 Bratislava, Slovakia.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Garaj
authors.affiliation: Institute of Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina CH-2, SK-842 15 Bratislava, Slovakia.
authors.forename: Anton
authors.initials: A
authors.lastname: Gáplovský
mesh_terms: D000085:Acetates / Q000032:analysis*; D000838:Anions / Q000032:analysis; D003124:Colorimetry / Q000379:methods; D005459:Fluorides / Q000032:analysis*; D007211:Indoles; D007536:Isomerism; D012664:Semicarbazones / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D000085:Acetates; D000838:Anions; D007211:Indoles; D012664:Semicarbazones; C095912:N-methylisatin; D005459:Fluorides
keywords: Anion basicity; Anion induced tautomerism; Colorimetric sensors; Isatinphenylsemicarbazones; Self-association