Textbook Question
Some of the following compounds show aromatic properties, and others do not.
1. Predict which ones are likely to be aromatic, and explain why they are aromatic.
(n)
(o)
791
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Ch. 16 - Aromatic Compounds
Wade9th EditionOrganic ChemistryISBN: 9780135213728
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Table of contents
- Ch.1 - Structure and Bonding107
- Ch. 2 - Acids and Bases; Functional Groups115
- Ch.3 - Structure and Stereochemistry of Alkanes100
- Ch.4 - The Study of Chemical Reactions99
- Ch.5 - Stereochemistry93
- Ch.6 - Alkyl Halides; Nucleophilic Substitution118
- Ch. 7 - Structure and Synthesis of Alkenes; Elimination158
- Ch.8 - Reactions of Alkenes171
- Ch.9 - Alkynes91
- Ch.10 - Structure and Synthesis of Alcohols143
- Ch.11 - Reactions of Alcohols104
- Ch. 12 - Infrared Spectroscopy and Mass Spectrometry22
- Ch. 13 - Nuclear Magnetic Resonance Spectroscopy45
- Ch. 14 - Ethers, Epoxides, and Thioethers72
- Ch. 15 - Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy89
- Ch. 16 - Aromatic Compounds74
- Ch. 17 - Reactions of Aromatic Compounds126
- Ch. 18 - Ketones and Aldehydes193
- Ch. 19 - Amines129
- Ch. 20 - Carboxylic Acids77
- Ch. 21 - Carboxylic Acid Derivatives141
- Ch. 22 - Condensations and Alpha Substitutions of Carbonyl Compounds175
- Ch. 23 - Carbohydrates and Nucleic Acids93
- Ch. 24 - Amino Acids, Peptides, and Proteins54
Chapter 16, Problem 35e
Some of the following compounds show aromatic properties, and others do not.
1. Predict which ones are likely to be aromatic, and explain why they are aromatic.
2. Predict which nitrogen atoms are more basic than water and which are less basic.
(e) 
Verified step by step guidance1
Step 1: Analyze the structure of the compound provided in the image. The compound is a six-membered ring with alternating double bonds (a conjugated system) and a ketone functional group attached to the ring. This structure resembles a substituted benzene ring.
Step 2: Determine aromaticity using Huckel's rule. Huckel's rule states that a compound is aromatic if it is cyclic, planar, conjugated, and has (4n + 2) π-electrons, where n is an integer. Count the π-electrons in the conjugated system of the ring.
Step 3: Evaluate the conjugation and planarity of the compound. The alternating double bonds in the ring indicate conjugation, and the planar nature of the ring allows for delocalization of π-electrons. The ketone group does not disrupt the conjugation of the ring.
Step 4: Predict aromaticity. If the compound satisfies Huckel's rule with (4n + 2) π-electrons, it is aromatic. If it does not satisfy the rule, it is non-aromatic. Count the π-electrons in the ring to confirm.
Step 5: Assess the basicity of nitrogen atoms. Since the compound does not contain nitrogen atoms, this part of the question is not applicable to the given structure. Focus only on aromaticity for this compound.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Aromaticity
Aromaticity refers to the special stability and unique properties of cyclic compounds that have a planar structure, a fully conjugated pi-electron system, and follow Hückel's rule (4n + 2 pi electrons). Compounds that are aromatic exhibit resonance, which lowers their energy and increases stability. Identifying aromatic compounds involves checking for these criteria, which can help predict their reactivity and interactions.
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08:19
Intro to Aromaticity
Basicity of Nitrogen
The basicity of nitrogen atoms in organic compounds is influenced by their electronic environment and hybridization. Nitrogen atoms can donate a lone pair of electrons to protons (H+), making them basic. In aromatic systems, the presence of electronegative atoms or resonance can affect the availability of the lone pair, thus altering the basicity compared to water, which has a pKa of about 15.7.
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06:21Understanding the difference between basicity and nucleophilicity.
Heterocycles
Heterocycles are cyclic compounds that contain at least one atom other than carbon in the ring, such as nitrogen, oxygen, or sulfur. The presence of these heteroatoms can significantly influence the chemical properties, including aromaticity and basicity. Understanding the role of heteroatoms is crucial for predicting the behavior of these compounds in chemical reactions and their interactions with other molecules.
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2:06Nomenclature of Heterocycles Concept 1
Related Practice
Textbook Question
Each of the following heterocycles includes one or more nitrogen atoms. Classify each nitrogen atom as strongly basic or weakly basic, according to the availability of its lone pair of electrons.
(d)
(e)
1420
views
Textbook Question
Some of the following compounds show aromatic properties, and others do not.
1. Predict which ones are likely to be aromatic, and explain why they are aromatic.
2. Predict which nitrogen atoms are more basic than water and which are less basic.
(m)
465
views
Textbook Question
Some of the following compounds show aromatic properties, and others do not.
1. Predict which ones are likely to be aromatic, and explain why they are aromatic.
2. Predict which nitrogen atoms are more basic than water and which are less basic.
(d)
675
views
Textbook Question
Some of the following compounds show aromatic properties, and others do not.
1. Predict which ones are likely to be aromatic, and explain why they are aromatic.
(a)
(b)
(c)
1267
views
Textbook Question
Some of the following compounds show aromatic properties, and others do not.
1. Predict which ones are likely to be aromatic, and explain why they are aromatic.
2. Predict which nitrogen atoms are more basic than water and which are less basic.
(f)
503
views