1,9-Dithia[2.2]paracyclophane: Synthesis, Molecular Structure, and Properties

摘要

Since the isolation of [2.2]paracyclophane from a polymer mixture and its identification by X-ray analysis, many cyclophanes have been synthesized and their chemical and physical properties have been extensively studied. 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 nitrogen, oxygen, carbon dioxide, and hydrogen gases and to moisture vapor. Strained [2.2]paracyclo-phanes undergo vapor-phase pyrolysis under reduced pressure at high temperature (600℃) to give very reactive p-quinodimethanes quantitatively which con- dense on a cold surface below 30℃ and polymerize spontaneously to give colorless transparent films free from contamination and cross-linking.