Textbook Question
What are the products of the following reactions?
c.
d.
1
views
Ch. 18 - Reactions of Benzene and Substituted Benzenes
Bruice8th EditionOrganic ChemistryISBN: 9780135213711
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 1)31
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 2)65
- Ch. 2 - Acids and Bases: Central to Understanding Organic Chemistry84
- Ch. 3 - An Introduction to Organic Compounds:Nomenclature, Physical Properties, and Structure183
- Ch. 4 - Isomers: The Arrangement of Atoms in Space121
- Ch. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics83
- Ch. 6 - The Reactions of Alkenes • The Stereochemistry of Addition Reactions175
- Ch. 7 - The Reactions of Alkynes • An Introduction to Multistep Synthesis119
- Ch. 8 - Delocalized Electrons: Their Effect on Stability, pKa, and the Products of a Reaction • Aromaticity and Electronic Effects: An Introduction to the Reactions of Benzene148
- Ch. 9 - Substitution and Elimination Reactions of Alkyl Halides212
- Ch. 10 - Reactions of Alcohols, Ethers, Epoxides, Amines, and Sulfur-Containing Compounds131
- Ch. 11 - Organometallic Compounds60
- Ch. 12 - Radicals90
- Ch. 13 - Mass Spectrometry; Infrared Spectroscopy; UV/Vis Spectroscopy62
- Ch. 14 - NMR Spectroscopy95
- Ch. 15 - Reactions of Carboxylic Acids and Carboxylic Acid Derivatives123
- Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives141
- Ch. 17 - Reactions at the Alpha-Carbon101
- Ch. 18 - Reactions of Benzene and Substituted Benzenes144
- Ch. 19 - More About Amines • Reactions of Heterocyclic Compounds49
- Ch. 20 - The Organic Chemistry of Carbohydrates80
- Ch. 21 - Amino Acids, Peptides, and Proteins57
- Ch. 22 - Catalysis in Organic Reactions and in Enzymatic Reactions35
- Ch. 23 - The Organic Chemistry of the Coenzymes—Compounds Derived from Vitamins1
- Ch. 28 - Pericyclic Reactions58
Chapter 19, Problem 55f
Rank each group of compounds from most reactive to least reactive toward electrophilic aromatic substitution:
f. bromobenzene, chlorobenzene, fluorobenzene, iodobenzene
Verified step by step guidance1
Understand the concept of electrophilic aromatic substitution (EAS): This reaction involves the substitution of a hydrogen atom on an aromatic ring with an electrophile. The reactivity of the aromatic ring depends on the electronic effects of substituents already present on the ring.
Analyze the substituents on the benzene ring: In this case, the substituents are halogens (bromine, chlorine, fluorine, and iodine). Halogens are electron-withdrawing groups due to their inductive effect (-I effect) but also have a resonance-donating effect (+R effect) because of their lone pairs.
Determine the net effect of halogens on reactivity: The inductive effect (-I) of halogens deactivates the ring by withdrawing electron density, making it less reactive toward EAS. However, the resonance effect (+R) can donate electron density back to the ring, partially counteracting the deactivation. The balance between these effects depends on the halogen's electronegativity and size.
Rank the halogens based on their electronegativity and resonance effects: Fluorine is the most electronegative, so its inductive effect dominates, making fluorobenzene the least reactive. Iodine is the least electronegative and has a weaker inductive effect, so its resonance effect is more significant, making iodobenzene the most reactive. Bromine and chlorine fall in between, with bromine being slightly less deactivating than chlorine due to its lower electronegativity.
Conclude the ranking: Based on the analysis, the order of reactivity toward electrophilic aromatic substitution is iodobenzene > bromobenzene > chlorobenzene > fluorobenzene.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
4mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Electrophilic Aromatic Substitution (EAS)
Electrophilic Aromatic Substitution is a fundamental reaction in organic chemistry where an electrophile replaces a hydrogen atom on an aromatic ring. This process is crucial for understanding the reactivity of aromatic compounds, as the stability of the aromatic system influences how readily it can react with electrophiles.
Recommended video:
Guided course
03:07
EAS Review
Halogen Substituents and Their Effects
Halogen substituents (like bromine, chlorine, fluorine, and iodine) on an aromatic ring can either activate or deactivate the ring toward electrophilic substitution. While they are generally deactivating due to their electronegativity, their relative positions in the periodic table affect their reactivity, with larger halogens typically being less electronegative and more polarizable, thus influencing the overall reactivity.
Recommended video:
2:02Directing Effects in Substituted Pyrroles, Furans, and Thiophenes Concept 1
Resonance and Inductive Effects
The resonance and inductive effects of substituents on an aromatic ring play a significant role in determining reactivity. Electron-withdrawing groups decrease electron density on the ring, making it less reactive, while electron-donating groups increase electron density, enhancing reactivity. Understanding these effects is essential for ranking the reactivity of halogenated aromatic compounds.
Recommended video:
Guided course
01:47Understanding the Inductive Effect.
Related Practice
Textbook Question
Rank each group of compounds from most reactive to least reactive toward electrophilic aromatic substitution:
a. benzene, ethylbenzene, chlorobenzene, nitrobenzene, anisole
1
views
Textbook Question
Rank each group of compounds from most reactive to least reactive toward electrophilic aromatic substitution:
b. 1-chloro-2,4-dinitrobenzene, 2,4-dinitrophenol, 1-methyl-2,4-dinitrobenzene
2
views
Textbook Question
For each of the following compounds, indicate the ring carbon(s) that is/are nitrated when the compound is treated with HNO3/H2SO4:
a.
b.
7
views
Textbook Question
What are the products of the following reactions?
f.
2
views
Textbook Question
Rank each group of compounds from most reactive to least reactive toward electrophilic aromatic substitution:
e. p-methylnitrobenzene, 2-chloro-1-methyl-4-nitrobenzene, 1-methyl-2,4-dinitrobenzene, p-chloromethylbenzene
1
views