We synthesized several polyether dicarboxylic acids with naphthalene and tr
imethylene groups as repeating units. The polyethers selectively formed com
plexes with lithium, an alkali metal. In contrast to the typical polyethers
, their alkali metal complexes exhibited very low solubilities for water an
d hydrophobic organic solvents such as chloroform and toluene. Polyethers h
aving seven naphthalene units formed a stable monolayer on an aqueous subph
ase, only when alkali metal hydroxides were added, but not acid.