I1,Aromaticity and Reactivity ■4.芳香性判别(Huckel rules) >闭合的共轭体系（环状π电子流） >4n+2 Cyclopentadienyl Anion Planar... 6πelectrons, therefore aromaticI1、 Aromaticity and Reactivity „4.芳香性判别(Hückel rules) ¾闭合的共轭体系(环状π电子流) ¾4n+2