Triiodide Ion‐Selective Electrode Based on Charge‐Transfer Complex of 4,7,13,16,21,24‐Hexaoxa‐1,10‐diazabicyclo‐[8.8.8]hexacosane

Abstract

Two new highly selective triiodide electrodes have been prepared using charge‐transfer complex of iodine with cryptand 222 as an electroactive ionophore and nitrophenyl octyl ether as a plasticizing agent. The electrodes showed Nernstian response to triiodide ions over a concentration range from 1.0 × 10−;2 — 7.9 × 10−;7 M and from 1.0 × 10−;2 — 1 × 10−;6 M with detection limits of 6.3 × 10−;7 and 7.9 × 10−;7 M for cryptand and its charge‐transfer complex with iodine, respectively. The response times (t95%) of the sensors were 10 and 5 s. The membrane could be used for more than 1 month without any divergence in potentials. The proposed sensors exhibited very high selectivity for triiodide ion over other anions, and could be used in a wide pH range ˜2–10. These electrodes were successfully applied as an indicator electrode in potentiometric titration of copper in ore samples.

Triiodide PVC Membrane Electrode Based on a Charge‐Transfer Complex of Iodine with Ditertbutyl‐Dicyclohexyl‐18‐Crown‐6

“…7,10 On the other hand, it seems that the substitution of the electron donating tertiary butyl dicyclo groups on 18C6 moiety causes it to become highly insoluble in water, as a result, the electrode life time increase. Furthermore, as mentioned before, 8 with the usage of the ligand alone in the membrane, we don't need to prepare a charge transfer complex and therefore escapes a time consuming procedure for making ionophore. Due to such interesting features, we examined (t-Bu) 2 DC18C6 as a potential sensing material in the construction of new PVC-base I 3 --selective electrodes.…”

“…The general procedure to prepare the PVC membranes was to mix thoroughly 34.3 mg of powder PVC, 60 mg of plasticizer NPOE in 5 mL of THF as described previ-ously. 7,8,15 To this solution, 1.1 mg of ionophore (I) and 0.3 mg NaTPB were added and mixed well. The resulting mixtures were transferred into a glass dish of 2 cm diameter.…”

“…14 Ttherefore, a sensitive method is required for its reliable measurement. We have recently introduced two PVC-based membrane sensors for triiodide ions 7,8 using macrocyclic ligands (such as DBzDA18C6 7 and C222 8 ) as ion carrier. Although they are sensitive and very selective electrodes, they suffer from a short life time (1 month).…”

“…Research on anti-Hofmeister sensing material for anions is an expeditiously expanding domain in chemical sensors. Recently, anion membrane electrodes, especially those based on vitamin B12 derivatives, 3 metalloporphrins, 4 metallophtalocyanines, 5 Schiff-base complexes 6 and charge transfer complexes [7][8][9][10][11][12] have been reported as possessing improved characteristics in selectivity. Due to importance of triiodide ion in industry, pharmacology and environmental pollution, such as determination of copper, 8,13 iron 13 and antimony 13 in ore samples, determination of ascorbic acid and hydroquinone in drug 9 and determination of chlorine and dissolved O 2 in water.…”

New potentiometric sensor for the determination of iodine species

“…over other analysis methods [14]. Despite the need of direct or indirect determination of iodine as triiodide in many reactions, there have been few reports on triiodide electrodes [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. A research of new electrode-active substances is important.…”