Related Experiment Video
Updated: Oct 13, 2025

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Halogen Bonding Ionophore for Potentiometric Iodide Sensing
Georgina E K K Seah1, Angeline Y X Tan1, Zhi Hao Neo1
1Institute of Material Research and Engineering, A*STAR (Agency for Science, Technology and Research) Research Entities, 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Singapore.
Abstract:
Iodide (I-) is an essential micronutrient for thyroid function. Hence, rapid and portable sensing is important for I- quantification in food and biological samples. Herein, we report the first example of a halogen bonding (XB) tripodal ionophore (XB1) which is selective for the I- anion. NMR binding studies of XB1 and its H-triazole analog HB2 with I- demonstrated the dominant influence of XB interactions between the ionophore and the I- analyte. The phase boundary model was applied to formulate iodide-selective electrodes with the ionophore XB1. The optimal electrode exhibited a near-Nernstian response of -51.9 mV per decade within a large dynamic range (10-1 to 10-6 M) and notably anti-Hofmeister selectivity for I- over thiocyanate (SCN-), enabling the in situ determination of I- in complex samples. This work establishes XB as a viable supramolecular interaction in the potentiometric sensing of anions.
Related Concept Videos
Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
Potentiometry: Membrane Electrodes
Bond Polarity, Dipole Moment, and Percent Ionic Character
Precipitation of Ions
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:
Ion-Exchange Chromatography
Redox Titration: Iodimetry and Iodometry

