Novel ion-pair receptors based on hexahomotrioxacalix[3]arene derivatives

Ni, Xin Long; Rahman, Shofuir; Zeng, Xi; Hughes, David L.; Redshaw, Carl; Yamato, Takehiko

Abstract

A series of novel heteroditopic hexahomotrioxacalix[3]arene triamide receptors capable of binding an anion and cation simultaneously in a cooperative fashion has been prepared. The lower rim functionalized cone- hexahomotrioxacalix[3]arene derivatives cone-5a-5d bearing three amide groups were synthesized from cone-3 by a stepwise reaction. The crystal structures of 5c and 5d and 1H NMR studies in nonpolar solvents strongly indicate that a number of interesting intramolecular hydrogen bonding interactions exist in these receptors. The binding abilities of these compounds towards n-butylammonium chloride and bromide salts have been investigated using 1H NMR titration experiments in CDCl 3 solvent. Owing to the 'flattened cone' conformations and intramolecular hydrogen bonding involving the amide NH and neighbouring O atoms in cone-5a-5d, the affinities toward n-Bu 4NX (X = Cl - and Br -) were weakened. However, it should be noted that triamides cone-5a-5d show a single selectivity for halide anions in the presence of n-BuNH 3+ through intermolecular hydrogen bonding with the amide NH hydrogen atoms in the receptors in CDCl 3 solution. Association constants were calculated from the chemical shift changes of the amide protons. © 2011 The Royal Society of Chemistry.

Citation

Ni, X. L., Rahman, S., Zeng, X., Hughes, D. L., Redshaw, C., & Yamato, T. (2011). Novel ion-pair receptors based on hexahomotrioxacalix[3]arene derivatives. Organic & biomolecular chemistry, 9(19), 6535-6541. https://doi.org/10.1039/c1ob05564j

• Journal Article Type: Article
• Acceptance Date: May 17, 2011
• Online Publication Date: May 18, 2011
• Publication Date: Oct 7, 2011
• Deposit Date: Jun 8, 2022
• Journal: Organic and Biomolecular Chemistry
• Print ISSN: 1477-0520
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 19
• Pages: 6535-6541
• DOI: https://doi.org/10.1039/c1ob05564j
• Public URL: https://hull-repository.worktribe.com/output/3622374