4, 4′, 5, 5′-Tetraiododibenzo-24-crown-8 (), a practical building block, was prepared under efficient and mild reaction conditions starting from the simple starting material, catechol (). Highly conjugated 4, 4′, 5, 5′-tetraethynyldibenzo-24-crown-8) were prepared via a Sonogashira coupling reaction from tetraiodocrown ether. These highly conjugated crown ethers form complexes in CD2Cl2 with dibenzylammonium hexafluorophosphate in ...