| Abstract: | α-Hydroxyisopropylferrocene, HPF, was synthesized in good yield and polymerized at 20°C with either SnCl4 or BF3OEt2. The polymerization proceeds by self-alkylation of the stable intermediate ferrocenylcarbenium ion on the cyclopentadienyl ring to form oligomers that contain both homoannular and heteroannular links. The unusually high stability of the α-isopropylferrocenylcarbenium ion was demonstrated by synthesizing and isolating α-isopropylferrocenylcarbenium tetrafluoborate from HPF and using it to initiate the polymerization of styrene. Initiation was successful at 20° and at 0°C, but no polymerization occurred ?78°C. The condensation of ferrocene and acetone in the presence of AlCl3 gave oligomers having structures very similar to those obtained from the cationic polymerization of isopropenylferrocene. |
