Synthesis and binding studies of novel thiacalixpodands and bisthiacalixarenes having O,O″-dialkylated thiacalix[4]arene unit(s) of 1,3-alternate conformation

Thiacalixpodand 7a, as well as a bisthiacalixarene of the related structure, quantitatively and selectively extracts silver ion from aqueous into organic phase under neutral conditions. Compound 7a forms a 1:2 (L:M) complex with silver ion as proved by NMR spectroscopy, Job's plot and X-ray crystallography.