Abstract
Bis[(2-pyridylmethyl)oxy]tetrathiacalix[4]arenes with 1,3- alternate conformation show strong Ag
+
affinity and high Ag
+
selectivity. The conformational changes of the pyridine moiety from the original outward orientation of the ring nitrogen to the inside orientation toward the thiacalixarene cavity were observed in the process of Ag
+
complexation. The structure of a representative thiacalixarene compound in the 1,3- alternate conformation has been determined by X-ray crystallography.