A Cr(VI) selective probe based on a quinoline-amide calix[4]arene

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 189; pp. 44 - 50
• Main Authors: Ferreira, Juliane F., Bagatin, Izilda A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-01-2018
• Subjects: Dichromate; Hazardous anions; Hydrogen-bonds; Mercury; Quinoline; Sensor; Hydrogen-bonds; Hazardous anions; Quinoline; Dichromate; Mercury; Sensor
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2017.07.056

A new quinoline-amide calix[4]arene 3-receptor for detection of hazardous anions and cations have been synthesized. The 3-receptor was examined for its sensing properties towards several different anions (Cr2O72−, SCN−, F−, Cl−, NO3−) and metal ions (Hg2+, Cd2+, Ag+) by UV–vis and fluorescence spectroscopies. It was detected that the 3-receptor has only sensing ability for Cr2O72− and Hg2+ ions, resulting in the association constants higher for Cr2O72− than to the Hg2+ ions. High selectivity towards Cr2O72− were also observed by fluorescence measurement among other ions (F−, Cl−, SCN−, Hg2+, Cd2+, Ag+) with a low limit of detection (7.36×10−6moldm−3). Proton NMR anion-binding investigations revealed a strong interaction of Cr2O72− anion with NH and CH groups of the receptor, showing that the combination with hydrogen-bonds donor groups strengthened the anion receptor association. Furthermore, remarkable association constants for dichromate anion obtained by all techniques strongly suggest the 3-receptor as a selective Cr(VI) sensor.
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•Simultaneous association with NH and CH groups reflect synergistic anion binding ability of 3.•Selectivity of sensor towards Cr2O72− validated in the presence of interfering ions.•Remarkable association constants for Cr2O72− suggest 3 as a selective Cr(VI) sensor.•Low detection limit on sensor 3 for Cr2O72− was obtained by fluorescence measurement.•Development of probes for hazardous metals and toxic species could be enlarged.