Allyl radical nature of a phenylcyclopentadienyl radical annelated with two homoadamantene frameworks

摘要

1-Phenylcyclopentadiene fused with two homoadamantene units at the 2,3- and 4,5-positions (4) was deprotonated with KH to lead to the quantitative formation of the corresponding cyclopentadienyl (Cp) anion 3-. This anion was oxidized by AgCl to afford an orange crystalline solid consisting of Cp radical 3~? and cyclopentadiene 4. The ESR spectrum in hexane exhibited approximately 15 lines, demonstrating that the two homoadamantene frameworks were equivalent and that the C1-C2(Ph)-C3 moiety of the five-membered ring formed a symmetrical allyl-like radical in agreement with the prediction by DFT calculation. The reaction of the Cp radical 3~? with an oxygen molecule in the presence of Ag~+SbF_6- afforded the SbF_6- salt of a phenylpyrylium ion annelated with two homoadamantene frameworks (8~+SbF_6-).