Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

26. Amines

Amine Alkylation

Organic Chemistry

26. Amines

Amine Alkylation

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6:52 minutes

Problem 5

Textbook Question

Rank each set of compounds in order of increasing boiling points.
(a) triethylamine, di-n-propylamine, n-propyl ether
(b) ethanol, dimethylamine, dimethyl ether
(c) diethylamine, diisopropylamine, trimethylamine

Verified step by step guidance

Step 1: Understand the factors affecting boiling points. Boiling points are influenced by intermolecular forces such as hydrogen bonding, dipole-dipole interactions, and London dispersion forces. Compounds with stronger intermolecular forces generally have higher boiling points.

Step 2: Analyze the functional groups in each compound. For example, amines can form hydrogen bonds due to the presence of an N-H bond, ethers rely on dipole-dipole interactions, and alcohols can form strong hydrogen bonds due to the O-H bond.

Step 3: Consider molecular size and branching. Larger molecules with more surface area tend to have stronger London dispersion forces, leading to higher boiling points. Branching reduces surface area and weakens dispersion forces, lowering boiling points.

Step 4: Compare the compounds in each set based on their ability to form hydrogen bonds, molecular size, and branching. For example: (a) triethylamine has no N-H bond for hydrogen bonding, di-n-propylamine has N-H bonds and is less branched, and n-propyl ether relies on dipole-dipole interactions. (b) Ethanol has strong hydrogen bonding due to the O-H group, dimethylamine has weaker hydrogen bonding due to the N-H group, and dimethyl ether relies on dipole-dipole interactions. (c) Diethylamine has N-H bonds for hydrogen bonding, diisopropylamine is more branched, and trimethylamine lacks N-H bonds.

Step 5: Rank the compounds in each set in order of increasing boiling points based on the analysis. For example, prioritize compounds with stronger hydrogen bonding, larger molecular size, and less branching for higher boiling points.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Boiling Point and Intermolecular Forces

The boiling point of a compound is influenced by the strength of its intermolecular forces. Compounds with stronger forces, such as hydrogen bonding or dipole-dipole interactions, typically have higher boiling points. For example, alcohols like ethanol can form hydrogen bonds, leading to higher boiling points compared to ethers or amines that may have weaker interactions.

Hydrogen Bonding

Hydrogen bonding occurs when a hydrogen atom covalently bonded to a highly electronegative atom (like oxygen or nitrogen) interacts with another electronegative atom. This type of bonding significantly increases the boiling point of compounds. For instance, ethanol can form hydrogen bonds, while ethers and amines may not exhibit the same extent of hydrogen bonding, affecting their boiling points.

Molecular Structure and Size

The molecular structure and size of a compound also play a crucial role in determining its boiling point. Larger molecules generally have higher boiling points due to increased van der Waals forces. Additionally, branching in aliphatic amines can reduce boiling points compared to their straight-chain counterparts, as branching decreases surface area and thus the strength of intermolecular interactions.

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b. Explain why it can cross-link DNA.

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In Section 10.12, we saw that S-adenosylmethionine (SAM) methylates the nitrogen atom of noradrenaline to form adrenaline, a more potent hormone. If SAM methylates an OH group attached to the benzene ring instead, it completely destroys noradrenaline's activity.

b. Which reaction is more apt to occur, methylation on nitrogen or methylation on oxygen?

Textbook Question

Dimethylamine, (CH₃)₂NH, has a molecular weight of 45 and a boiling point of 7.4 °C. Trimethylamine, (CH₃)₃N, has a higher molecular weight (59) but a lower boiling point (3.5 °C). Explain this apparent discrepancy.

Textbook Question

Rank the following substituted anilines from most basic to least basic:

Textbook Question

In each pair of compounds, select the stronger base, and explain your choice.

(a) HOCH₂CH₂NH₂ or CH₃CH₂NH₂

(b) PhNH₂ or PhCH₂NH₂

Textbook Question

Within each structure, rank the indicated nitrogens by increasing basicity.

(c)

Textbook Question

Within each structure, rank the indicated nitrogens by increasing basicity.

(a)