CROWN-ETHER ALCOHOLS AS BIFUNCTIONAL LIGANDS FOR SIMULTANEOUS CATION COMPLEXATION AND ANION SOLVATION

Structural modification of crown ethers by attachment of one or more pendant hydroxyl groups offers the potential for anion solvation as well as cation complexation by the ligand. Molecular structures have been determined for LiNCS complexes of two dibenzo-14-crown-4 alcohols and a dibenzo-14-crown-4 diol as well as a LiNO3 complex for one of the alcohols. Crystal structures for these four complexes show intracomplex ''scorpion-like'' and intercomplex ''head-to-tail'' hydrogen bonding of the crown ether hydroxyl groups with the anions. These complexes provide the first demonstration of the exploitation of structurally modified crown ethers as bifunctional ligands for simultaneous anion solvation and cation complexation.