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

作者：Tuntulani T^*; Poompradub S; Thavornyutikarn P; Jaiboon N; Ruang****visuti V; Chaichit N; Asfari Z; Vicens J

来源：Tetrahedron Letters, 2001, 42(32): 5541-5544.

DOI：10.1016/S0040-4039(01)01029-2

• aza crown
• calix[4]arene
• anion binding
• proton NMR titration

Tripodal aza crown ether calix[4]arenes containing both cation and anion binding sites (5a and 5b) have been synthesized. The X-ray analysis shows that 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 compounds form more stable complexes with I- than with Br- in the presence of BU4N+. The presence of K+ enhances the binding ability of 5a towards Br-.

• 出版日期2001-8-6