Polymerization of Ethylene Oxide with Alkyllithium Compounds and the Phosphazene Base “tBu[BOND]P4


  • We thank Prof. Dr. S. Boileau, College de France, Paris, for fruitful discussions, and Dr. U. Werz and U. Ziegler for conducting the NMR experiments.


Well-defined poly(ethylene oxide)s with low polydispersities are formed in the anionic polymerization of ethylene oxide with an alkyllithium/phosphazene base initiator system. The base can be regarded as a cryptand for Li+ ions. The equilibrium between complexed alkoxide ion pairs and reactive free anions is thus shifted.