Recognising how resonance contribtutes to the arrangement of charge around a ring helps to understand the reactivity of a substituted benzene.Consider the resonance contributors of the following compoundAccording to resonance, is the ring: activated or deactivated to electrophilic substitution. And which site/s are the most susceptible to substitution?

Question

BlackTom AI · Accepted Answer

The question asks us to evaluate resonance effects on a substituted benzene ring and determine both the overall reactivity (activated or deactivated) toward electrophilic substitution and which positions are most susceptible.
Option a: Deactivated - ortho sites are the most active. This is inconsistent with common directing effects: when a ring is deactivated, it is usually due to electron-withdrawing groups, and the ortho/para positions are not the most activated ones under deactivation. In many cases, deactivation also correlates with meta directing, not specifically ortho.
Option b: Activated - ortho and para sites are the most active. Activation implies an electron-donating or resonance-donating substituent that increases electron density on the ring, especially at the ortho and para positions. If the substituent were strongly activating, this could be true, but the resonance patterns shown in typical benzene derivatives with electron-withdrawing features do not support activation.
Option c: Activated - meta sites are the most active. Activation tends to direct to ortho and para, not meta. Meta substitution is typically associated with deactivating, electron-withdrawing groups, not with activating groups.
Option d: Deactivated - ortho and para sites are the most active. This combination is inconsistent: a deactivated ring generally reduces activity overall, and among deactivating groups, meta positions are usually favored, not ortho/para.
Option e: Deactivated - meta sites are the most active. This aligns with classic directing effects: electron-withdrawing or resonance-withdrawing substituents deactivate the ring and direct electrophilic substitution to the meta positions, where resonance structures place positive charge away from the substituent and stabilize the transition state less at ortho/para. The provided resonance contributors likely show withdrawal from the ring, leading to a meta-directing outcome and overall deactivation.
In summary, the incorrect options mix activation with ortho/para or misassign meta directing, while the meta-directing, deactivating scenario described in option e matches standard resonance/inductive effects observed for electron-withdrawing substituents on benzene rings.

My LMS Subjects Practice LMS questions, Week 3

查看解析

登录即可查看完整答案

类似问题

Which of the following, will provide a meta, nitro (NO2) compound, upon nitration with HNO3/H2SO4?

Which of the following is true about an ACTIVATOR for electrophilic aromatic substitution? (select all that apply)

Which of these reagents will NOT react with benzene by electrophilic aromatic substitution. (select all that apply)

更多留学生实用工具

考试浏览器助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单