Onder Alici

A novel colorimetric and fluorescent sensor based on calix[4]arene possessing triphenylamine units.

A novel colorimetric and fluorometric calix[4]arene probe (CTP) bearing triphenylamine units was synthesized in good yield and characterized by combination of (1)H, (13)C, APT, COSY, FTIR, HRMS, and UV-vis spectral data. Ion-binding studies of CTP were investigated in acetonitrile with a wide range of cations and anions and the recognition process was monitored by luminescence, UV-vis and (1)H NMR spectral changes. CTP exhibited naked eye detection for Hg(2+) ion. Also it showed a significant fluorescence quenching towards F(-) ion.

Synthesis of a new colorimetric receptor based on calix[4]pyrrole binding oxime for selective recognition of fluoride ions

A colorimetric anion sensor α-meso-heptaethylcalix[4]pyrrole-meso-3-aminophenyl-p-nitrobenzaldoxime was synthesised and characterised by various spectroscopic techniques. Anion-binding studies were carried out using UV–vis, and 1H NMR titrations, revealing that the receptor exhibits selective recognition towards F− over other anions. The selectivity for F− among the halides is attributed mainly to the hydrogen bond interaction of the receptor with F− . Receptor showed colour change from colourless to yellow in the presence of tetrabutylammonium fluoride with 1:2 stoichiometry. Cyclic voltammetry studies, carried out in CH3CN, provided evidence of an anion-dependent electrochemical response with F− ion. This response was particularly dramatic in the case of receptor after the addition of ∼1 equiv. of F− ion.

Sorption and kinetic properties of 2-(biphenyl-4-yl)-2-oxoacetaldehyde oxime towards Zn(II) ion

Abstract This study contains the synthesis of 2-(biphenyl-4-yl)-2-oxoacetaldehyde oxime (keto oxime) and its sorption studies towards Zn(II) ions in aqueous solution. In batch sorption experiments, the experimental results show that keto oxime is an effective sorbent towards Zn(II) ions. Therefore, the effects of solution pH, sorption time, temperature, and initial metal ion concentration on Zn(II) sorption were investigated. Maximum Zn(II) ions removal was obtained at 65°C, for 75 min and at pH 5.0 for keto oxime and the batch sorption capacity was found as 1.00 mmol/g. The characteristics of the sorption process for Zn(II) ions were evaluated by using the Langmuir and Freundlich adsorption isotherms. Also, thermodynamic parameters, i.e. ΔG, ΔS, and ΔH were calculated for the system.