Synthesis of a tweezer-like bis(arylthiaalkoxy)calix[4]arene as a cation sensor for ion-selective electrodes: an investigation of the influence of neighboring halogen atoms on cation selectivity

• Published in: Organic & biomolecular chemistry Vol. 1; no. 6; pp. 1073 - 1079
• Main Authors: Zeng, XS, Sun, H, Chen, LX, Leng, XB, Xu, FB, Li, QS, He, XW, Zhang, WQ, Zhang, ZZ, Zhang, Z
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 21.03.2003
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; POTENTIOMETRIC SELECTIVITY; SIDE-ARM; SODIUM-ION; SILVER; CESIUM; BULK OPTODES; DIBENZO-16-CROWN-5 COMPOUNDS; MEMBRANE ELECTRODES; FUNCTIONALIZED CALIX ARENES; DERIVATIVES
• ISSN: 1477-0520
• DOI: 10.1039/b211381c

Two novel tweezer-like 25,27-dihydroxy-26,28-bis(phenylthiaethoxy)calix[4]arenes 6 and 7 were synthesized by the reaction of 25,27-dihydroxy-26,28-bis(bromoethoxy) calix[4] arenes 3 and 4 for the evaluation of their ion-selectivity in ion-selective electrodes (ISEs). X-ray structural analysis indicated that calix[4] arene 7 is in an interesting infinite linear aggregate via self-inclusion. For investigation of the influences of substitutes on the behavior of the ISEs, the halogen substituted aryl analogues of 25,27-dihydroxy-26,28-bis(arylthiaethoxy)calix[4]arenes 8-12 were also synthesized and their ISE performances were evaluated under the same conditions. ISEs based on 6-12 as neutral ionophores were prepared, and their selectivity coefficients for Ag+ (log K-Ag,M(pot)) were investigated against other alkali metal, alkaline-earth metal, lead, ammonium ions and some transition metal ions using the fixed interference method (FIM). These ISEs showed excellent Ag+ selectivity over most of the interfering cations examined, except for Hg2+ having relative smaller interference (log K-Ag,Hg(pot) less than or equal to 2.1). The F-19 NMR spectra of 9 and 9.AgClO4 were recorded for investigation the fluorine environments in the complex. The F-19 NMR spectra strongly suggested that the fluorine atoms on ionophore 9 participated in ligation with silver cation.