Aromatic Bridged Bis-phenol A Derived Cyclophanes. Synthesis, Molecular Structure and Binding Properties Toward Quats

Three novel polyoxyethylene bridged bis phenol A derived cyclophanes, {\rm 2 -- 4,} with additional aromatic units in the bridge to increase the number of cation–π interactions with guest cations, were synthesized and characterized by means of X-ray crystal structure determinations. The binding properties of these receptors toward tetramethylammonium (TMA), N-methylpyridinium (NMP), acetylcholine (ACh) and N-methylquinolinium (NMQ) salts were evaluated by means of 1H NMR spectroscopy and compared with those of the previously reported receptor 1.