薁 l0元-electrons The two major (neutral)resonance forms for azulene... Aromatic “cyclopentadiene e“cycloheptatriene Zwitterionic anion-like” cation-like” 两性离子的 ...and the very stable Zwiterionic form
◆ 薁 Zwitterionic 两性离子的
8 薁 5 3 8 >350℃ 6 2 异构化 5 3
薁
se so S@ 6白 6⊕ 6由 Contrast the electron density map of azulene with that of napthalene,which has no significant Zwitterionic component
并环戊二烯负离子 Account for the differences in reactivity between pentalene (an unknown compound)and the well-known pentalene dianion: very unstable stable 8 i-electrons; 10 -electrons; not aromatic aromatic
并环戊二烯负离子
环辛五烯 Would you predict cyclodecapentaene to be an aromatic compound? 空间障碍 Cyclodecapentaene
空间障碍 环辛五烯