Synthesis of macrocyclic ionophore for the development of highly selective chloride sensor

Abstract

The macrocyclic ligands 3,8,12,17-tetramethyl-2,18,9,11-bipyridyl-1,4,7,10,13,16-hexaazacyclooctadecanetetrahydro bromide has been synthesized and explored as suitable ionophores for chloride selective membrane sensors. It displays Nernstian behavior (59.2 mV decade-1) across the range of 4.1 × 10 -8 to 1.0 × 10 -2 M. The detection limit of the electrode is ∼ 15 nM and the response time and life times are 14 s and eight weeks respectively over a wide pH range (3.5-9.5). Interference from other anions is very low and it can be used as indicator electrode in the potentiometric titration of chloride ions and to determine chloride in agricultural soil water samples.