一、导言关于苯环上取代反应中定位效应的解释,目前仍存在各种各样的理论,其主要分歧在于取代基引起苯环上电荷交替分布的机理。以英果尔德(Ingold)为首的中介論者,认为取代基引入苯环后,将以誘导效应和中介效应等作用于苯环,两种作用都在苯环上成圓环形方式传播。以鮑林(Pauliog)为首的共振論者,則以所謂极限結构之間的 I. INTRODUCTION There are still a variety of theories about the explanation of the orientation effect in the substitution reaction on benzene rings. The main difference lies in the mechanism that the substituents cause the alternating distribution of charges on the benzene ring. Intermediaries, led by Ingold, believe that when a substituent is introduced into a benzene ring, it will act on the benzene ring by inducing and mediating effects, and both of them act in a circular manner on the benzene ring. Resonators headed by Pauliog are based on the so-called limit structure