Aza crown ether calix[4]arenes containing cation and anion binding sites: effects of metal ions towards anion binding ability

Authors
Tuntulani, T Poompradub, S Thavornyutikarn, P Jaiboon, N Ruangpornvisuti, V Chaichit, N Asfari, Z Vicens, J
Citation
T. Tuntulani et al., Aza crown ether calix[4]arenes containing cation and anion binding sites: effects of metal ions towards anion binding ability, TETRAHEDR L, 42(32), 2001, pp. 5541-5544
Citations number
16
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
42
Issue
32
Year of publication
2001
Pages
5541 - 5544
Database
ISI
SICI code
0040-4039(20010806)42:32<5541:ACECCC>2.0.ZU;2-4
Abstract
Tripodal aza crown ether calix[4]arenes containing both cation and anion bi nding sites (5a and 5b) have been synthesized. The X-ray analysis shows tha t 5a forms a self-threaded rotaxane-like structure in the solid state. H-1 NMR titrations of the two ligands with various halide anions indicate that 5a and 5b can form complexes with Br- and I- but not F-. However, both comp ounds form more stable complexes with I- than with Br- in the presence of B U4N+. The presence of K+ enhances the binding ability of 5a towards Br-. (C ) 2001 Elsevier Science Ltd. All rights reserved.