Hydrophilic and hydrophobic carboxamide pincers as anion hosts.

Hydrophobic and hydrophilic, monotopic and ditopic carboxamide pincer hosts containing ethyl, hexyl, 2-hydroxyethyl and 2-hydroxyethyl ethyl ether pendant arms were synthesized. Solubility trends indicated that solubilities in water or hydrocarbon solvents varied depending on the nature of the pendant arms. Binding constants for hydrophilic pincers were larger in general than their hydrophobic analogs. Significant synergistic binding effects for the ditopic hosts were not observed.