Since the isolation of [2.2] paracyclophane from a polymer mixture and its identification by X- ray analysis, 1-3 many cyclophanes have been synthesized and their chemical and physical properties have been extensively studied. 4, 5 In the polymer field, it has long been recognized that strained [2.2] paracyclophanes are useful precursors of thin poly (arylene- ethylene) films which are inert and transparent and have excellent barrier properties to ...