12.3B Resonance description of the ally radical (烯丙基自由基的共振论的描述) 123 H2C=G—CH2 2CH CH212.3B Resonance description of the allyl radical (烯丙基自由基的共振论的描述） H2 C C H CH2 H2 C C H CH2 1 2 3 1 2 3