Textbook Question
(i) Classify the following molecules as aromatic, nonaromatic, or antiaromatic.
(ii) For aromatic molecules, solve for n in Hückel’s rule. For all other molecules, explain which rule of aromaticity is being broken.
(h)
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Ch. 23 - Benzene I: Aromatic Stability and Substitution Reactions
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471
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Table of contents
- Ch. 2 - General Chemistry Translated: Finding the Electrons114
- Ch. 3 - Alkanes and Cycloalkanes: Properties and Conformational Analysis109
- Ch. 4 - Acids and Bases: Electron Flow144
- Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics118
- Ch. 6 - Stereoisomerism: Arrangement of Atoms in Space112
- Ch. 7 - Principles of Green (Organic) Chemistry3
- Ch. 8 - Alkenes I: Properties and Electrophilic Additions158
- Ch. 9 - Alkenes II: Oxidation and Reduction150
- Ch. 10 - Alkynes: Electrophilic Addition and Redox Reactions101
- Ch. 11 - Properties and Synthesis of Alkyl Halides: Radical Reactions108
- Ch. 12 - Substitution and Elimination: Reactions of Haloalkanes172
- Ch. 13 - Alcohols, Ethers and Related Compounds: Substitution and Elimination239
- Ch. 14 - Structural Identification I: Infrared Spectroscopy and Mass Spectrometry54
- Ch. 15 - Structural Identification II: Nuclear Magnetic Resonance Spectroscopy93
- Ch. 16 - Metals in Organic Chemistry48
- Ch. 17 - Carbonyl Addition Reactions: Aldehydes and Ketones45
- Ch. 18 - Nucleophilic Acyl Substitution I: Carboxylic Acids18
- Ch. 19 - Nucleophilic Acyl Substitution II: Carboxylic Acid Derivatives39
- Ch. 20 - Enolates: Carbonyl Addition and Substitution13
- Ch. 21 - Conjugated Systems I: Stability and Addition Reactions56
- Ch. 22 - Conjugated Systems II: Pericyclic Reactions54
- Ch. 23 - Benzene I: Aromatic Stability and Substitution Reactions64
- Ch. 24 - Benzene II: Reactions Influenced by the Aromatic Ring62
- Ch. 25 - Amines: Structure, Reactions, and Synthesis27
- Ch. 26 - Amino Acids, Proteins, and Peptide Synthesis9
- Ch. 27 - Carbohydrates, Nucleic Acids, and Lipids54
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
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Mullins 1st EditionCh. 23 - Benzene I: Aromatic Stability and Substitution ReactionsProblem 61i
Mullins 1st EditionCh. 23 - Benzene I: Aromatic Stability and Substitution ReactionsProblem 61iChapter 22, Problem 61i
(i) Classify the following molecules as aromatic, nonaromatic, or antiaromatic.
(ii) For aromatic molecules, solve for n in Hückel’s rule. For all other molecules, explain which rule of aromaticity is being broken.
(i) 
Verified step by step guidance1
Identify the molecule: The structure shown is naphthalene, which consists of two fused benzene rings.
Determine the number of π-electrons: Each benzene ring contributes 6 π-electrons, so naphthalene has a total of 10 π-electrons.
Apply Hückel's rule: For a molecule to be aromatic, it must have (4n + 2) π-electrons, where n is a non-negative integer.
Solve for n in Hückel's rule: Set 4n + 2 = 10 and solve for n. This will help determine if the molecule is aromatic.
Conclude the classification: If n is a whole number, the molecule is aromatic. If not, consider if the molecule is nonaromatic or antiaromatic based on its structure and electron count.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Aromaticity
Aromaticity is a property of cyclic, planar structures with a ring of resonance bonds that leads to enhanced stability. For a molecule to be aromatic, it must follow Hückel's rule, which requires a conjugated system with (4n + 2) π electrons, where n is a non-negative integer. This rule helps determine the electron count needed for aromatic stability.
Recommended video:
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08:19
Intro to Aromaticity
Hückel's Rule
Hückel's rule is a criterion used to determine if a planar ring molecule is aromatic. It states that a molecule is aromatic if it has (4n + 2) π electrons, where n is a non-negative integer. This rule is crucial for identifying aromatic compounds, as it explains the electron configuration that contributes to the molecule's stability and reactivity.
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03:54The 18 and 16 Electron Rule
Antiaromaticity and Nonaromaticity
Antiaromatic compounds are cyclic, planar, and have a conjugated system, but they contain 4n π electrons, leading to instability. Nonaromatic compounds lack one or more of the criteria for aromaticity, such as planarity or a fully conjugated system. Understanding these distinctions helps classify molecules and predict their chemical behavior.
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02:58Determine the aromaticity
Related Practice
Textbook Question
Use a Frost circle diagram to construct the molecular orbital diagram for the molecules shown. Would you expect them to be aromatic or antiaromatic?
(a)
417
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Textbook Question
Use a Frost circle diagram to construct the molecular orbital diagram for the molecules shown. Would you expect them to be aromatic or antiaromatic?
(c)
426
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Textbook Question
Use a Frost circle diagram to construct the molecular orbital diagram for the molecules shown. Would you expect them to be aromatic or antiaromatic?
(b)
788
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Textbook Question
(i) Classify the following molecules as aromatic, nonaromatic, or antiaromatic.
(ii) For aromatic molecules, solve for n in Hückel’s rule. For all other molecules, explain which rule of aromaticity is being broken.
(g)
451
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Textbook Question
(i) Classify the following molecules as aromatic, nonaromatic, or antiaromatic.
(ii) For aromatic molecules, solve for n in Hückel’s rule. For all other molecules, explain which rule of aromaticity is being broken.
(f)
489
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