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A novel colorimetric anion-chemosensor based on 1,10-phenanthroline-2,9-dicarbonyl-p-nitro-phenylhydrazine has been synthesized. Among the different anions tested, it shows the best selectivity towards AcO(-). The addition of acetate causes the color to change from yellow to red, which could be detected with naked eyes. The binding ability of chemosensor 1 with anions has been investigated through UV-vis spectral titrations. In addition, (1)H NMR experiment was carried out to explore the nature of interaction between chemosensor 1 and acetate., (Copyright © 2011 Elsevier B.V. All rights reserved.)

A novel selective and sensitive colorimetric receptor 1 (1, 10-phenanthroline-2, 9-dialdehyde bis-(-p-nitrophenylureasemicarbo-hydrazone)) based on urea showing distinctive color fading phenomenon towards H2PO4− ion was reported. Fancifully, the recognition process of receptor 1 to H2PO4− was not interfered by the existence of others anions. We have probed the binding mechanism of 1-H2PO4− that H2PO4− ion induced competitive hydrogen binding process via intramolecular hydrogen-bond by UV-vis, fluorescence, 1H NMR titrations and ESI-MS experiments. [ABSTRACT FROM AUTHOR]

Three new selective anion receptors containing the (thio)urea binding sites were developed, Indole-3-formaldehyde phenyl-semithiocarbazone, Indole-3-formaldehyde nitrophenyl-semithiocarbazone, and Indole-3-formaldehyde nitrophenyl-semicarbazone, nominated as receptors 1, 2 and 3, respectively. Receptor 1 shows high selective recognition for F only, while both receptor 2 and receptor 3 containing a p-nitro group show high selective recognition for AcO. The high selective recognition of these receptors to anions is further investigated by X-ray crystallography diffraction, UV-vis, fluorescence analyses and H NMR. Furthermore, receptor 2 changes from yellow to orange, and receptor 3 darkens when acetate is added, providing a way of detection by 'naked-eye'. [ABSTRACT FROM AUTHOR]

A novel selective and sensitive colorimetric receptor 1 (1, 10-phenanthroline-2, 9-dialdehyde bis-(-p-nitrophenylureasemicarbo-hydrazone)) based on urea showing distinctive color fading phenomenon towards H2PO4− ion was reported. Fancifully, the recognition process of receptor 1 to H2PO4− was not interfered by the existence of others anions. We have probed the binding mechanism of 1-H2PO4− that H2PO4− ion induced competitive hydrogen binding process via intramolecular hydrogen-bond by UV-vis, fluorescence, 1H NMR titrations and ESI-MS experiments. [ABSTRACT FROM AUTHOR]

Abstract: A novel artificial anion receptor based on phenylhydrazone structure was designed, synthesized and characterized. The binding behavior of the receptor to various anions was investigated by UV–vis fluorescence analyses. In addition, 1H NMR experiments were carried out to explore the nature of interaction between receptor 1 and acetate. The processes of sensing can literally be seen through the ‘naked-eye’ for the sharp color changes from yellow to purple. [Copyright &y& Elsevier]