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
Steric repulsion between the opposing hydrogens forces the system out of planarity,therefore the molecule is not aromatic
◆大环芳香体系 具有交替的单双键的单环多烯烃，通称为轮烯(annulenes) 共平面性或接近平面性，平面扭转又大于0.1nm 芳香性{ 轮内氢原子间没有或很少有空间排斥作用 元电子数目符合4n+2规则 [10]轮烯 [14]轮烯 [18]轮烯
◆ 大环芳香体系 具有交替的单双键的单环多烯烃，通称为轮烯（annulenes） 芳香性 共平面性或接近平面性，平面扭转又大于0.1nm 轮内氢原子间没有或很少有空间排斥作用 π电子数目符合4n+2规则 H H H H H H HH H H H H H H H H H H [18]轮烯 HH H H H H ［10］轮烯 ［14］轮烯
Buckminsterfullerene 62 i electrons,(4n+2 with n=15) not planar with considerable ring strain... the molecule appears aromatic,but is much more reactive than benzene
rugged.They can survive collisions metals and other materials at speeds in excess 20.000 miles per hour,a speed that would tear molecules apart 1mile=1.6 km 100m/s
1mile=1.6 km 100m/s