Abstract
distal-Tetrathiacalix[4]arene having [(5'-methyl-2,2'-bipyridyl)-5-yl]methoxy group with 1,3-alternate conformation was prepared, which shows strong Ag+ affinity and the high Ag+ selectivity. The conformational change of 2,2'-bipyridyl moiety from the original outward orientation of the ring nitrogen to the inside orientation toward the thiacalixarene cavity was observed in the process of Ag+ complexation.