Hybrid macrocyclic receptors based on lower rim functionalised thiacalix[4]arene and amino acids: Synthesis, structure and binding properties towards metal ions

摘要

Peptidothiacalixarene derivatives 4a-d and 7a-d have been synthesized in excellent yields by the reaction of methyl esters of glycine, L-alanine and D- and L-phenyl alanine with lower rim substituted 1,3-diacid chloride and tetraacid chloride derivatives of thiacalixarene. The conformational and hydrogen bonding properties of these conjugates have been investigated by means of ~1H NMR in the solution state and by X-ray crystallography in the solid state. Complexation studies performed by UV-Vis and ~1H NMR spectroscopy in acetonitrile solution show that the 1,3-disubstituted hybrids selectively bind Hg~(2+) ions and the orientation of the substituent on the chiral carbon is found to have a significant effect on the binding.