Topological and metal ion effects on the anion binding abilities of new heteroditopic receptors derived from p-tert-butylcalix[4]arene

✍ Scribed by Nisachol Nerngchamnong; Benjamas Chailap; Pannee Leeladee; Orawon Chailapakul; Chomchai Suksai; Thawatchai Tuntulani

• Publisher: Elsevier Science
• Year: 2011
• Tongue: French
• Weight: 428 KB
• Volume: 52
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2011.04.014

✦ Synopsis

Two derivatives of p-tert-butylcalix[4]arenes 1 and 2 containing diethyl ester and amidoferrocene units as cation and anion binding sites, respectively, have been synthesized. Both compounds were isomeric with different topology for accommodating ions. 1 H NMR spectroscopy, cyclic voltammetry, and square-wave voltammetry were used to study the binding abilities of receptors 1 and 2 toward anions. Both receptors were found to bind Br À and I À selectively in the presence of Na + . The electrochemically oxidized ferrocenium form of para-isomer 2 in the free form was found to sense AcO À selectively, but demonstrated a negative sensing in the presence of Na + . In contrast, the electrochemically oxidized ferrocenium form of meta-isomer 1 was found to enhance sensing of AcO À and Cl À in the presence of Na + .