【摘要】 利用1-甲基咔唑的分子结构参数,计算了吡咯环氮上氢原子与1-甲基间的距离,计算结果小于氢原子和1-甲基的范德华半径之和,说明氢原子和1-甲基之间存在空间位阻,这一作用迫使键角张大,或是发生扭转,使原子或基团离开芳香环平面,表明咔唑环上1-或8-甲基在化学热力学上是不稳定的,而在咔唑环可能的甲基化中,1-或8-甲基化反应速率较快,推测有更多的产物生成。更多还原

【Abstract】 The distance between hydrogen atom and 1-methyl radical on pyrrole in 1-methylcarbazole is calculated to be shorter than the sum of their van der Vaals’ radii.The result suggests that there is a steric hinderance between hydrogen atom and 1-methyl radical.This effect will stretch the bond angle or cause the atom and radical to lean away from carbazole ring.So 1-(or 8-) methyl radical on carbazole is unstable in themodynamics.Moreover,the faster rate of possible methylation on 1-(or 8-) side may suggest the production of more 1-(or 8-) substitutes.更多还原