Synthesis of novel acyclic and cyclic polyether ligands

Synthetic methods for the preparation of novel acyclic and cyclic polyether ligands are described in this dissertation. Several series of neutral crown and lariat ethers were prepared by reaction at a ring carbon of a lariat ether, reaction on the functional side arm of a lariat ether, and reduction of benzo-substituted crown and lariat ethers. The synthesis of new protonionizable acyclic polyether ligands and a variety of proton-ionizable lariat ethers was undertaken.

Substitution reactions at the central carbon of the three-carbon bridges of dibenzo-16-crown-5 compounds and their analogues provided new types of lariat ethers, such as pentafluorophenoxy-substituted lariat ethers, (nitrophenoxy)dibenzo-16-crown-5 compounds, and a series of (amino)dibenzocrown ethers. Lariat ether esters, lariat ether amides, and lariat ether amino acid esters were prepared by reactions on the side arm of lariat ethers allow for investigation of their metal ion complexing abilities in polymeric membrane electrodes and in solvent extraction. Cyclohexanosubstituted crown and lariat ethers were prepared by catalytic hydrogenation of the corresponding benzo-substituted crown and lariat ethers.

An acyclic polyether phosphonic acid monoethyl ester and some acyclic polyether dicarboxylic acids were synthesized for use in preparation of chelating polymers by condensation polymerization with formaldehyde and in solvent extraction of Pb(II).

To examine their abilities for lithium isotope separation by solvent extraction, synthesis of lipophilic crown-4 carboxylic acids was performed. Dicyclohexano-16-crown-5-oxyacetic acids and dibenzo-16-crown-5 amino acids were prepared to determine their extraction ability for alkali metal cations. Lariat ether oximes were prepared to probe the binding properties of an oxime function in the side arm. Synthesis of new types of chromogenic lariat ethers was performed for studies of their efficiencies and selectivities in metal ion extraction and their chromogenic response.