Synthesis and metal transport ability of a new series of thiamacrocycles containing thiol and disulfide groups inside the ring

Synthetic methods for thiamacrocycles containing two thiol groups or a disu lfide linkage and their abilities to effect single heavy-metal-ion transpor t across a liquid membrane were examined. High Ag+ selectivity was accompli shed by the thiol or disulfide hosts, although all the corresponding crown ether analogs bearing a disulfide group showed no Ag+ selectivity. The diff erence of the transport preferences among the thiacrown ethers prepared her e is considered to be reflected by the position and the number of the sulfu r atoms ligating to Ag+ and the cavity size of the hosts. (C) 2001 John Wil ey & Sons, Inc.