Chapter 18 Amines and Amides 18 2 Properties
- Slides: 12
Chapter 18 Amines and Amides 18. 2 Properties of Amines General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 1
Boiling Points of Amines, Alcohols, and Alkanes The boiling points of amines are § higher than alkanes of similar mass § lower than alcohols of similar mass General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 2
Hydrogen Bonding in Amines The polar N—H bond § provides hydrogen bonding in 1° and 2° amines but not 3° amines § is not as polar as the —OH in alcohols General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 3
Solubility in Water Amines are soluble in water § if they have 1 to 5 carbon atoms § because the N atom in smaller amines forms hydrogen bonds with the polar O—H bond in water General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 4
Learning Check Consider the following compounds: 1) CH 3—CH 2—NH 2 2) CH 3—CH 2—NH—CH 3 3) CH 3—CH 2—CH 3 A. Which compound has the highest boiling point? B. Which compound(s) is (are) soluble in water? General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 5
Solution Consider the following compounds: 1) CH 3—CH 2—NH 2 2) CH 3—CH 2—NH—CH 3 3) CH 3—CH 2—CH 3 A. Which compound has the highest boiling point? 1) CH 3—CH 2—NH 2 B. Which compound(s) is(are) soluble in water? 1) CH 3—CH 2—NH 2 2) CH 3—CH 2—NH—CH 3 General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 6
Amines React as Bases Amines are § Brønsted-Lowry bases that attract a H+ from H 2 O to the N atom § weak bases in water General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 7
Neutralization Forms Amine Salts An amine salt § forms when an amine is neutralized by an acid § is named by replacing the amine part of the name with ammonium followed by the name of the negative ion General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 8
Properties of Amine Salts Amine salts are § solids at room temperature § soluble in water and body fluids § the form used for drugs General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 9
Cocaine § is sold illegally as an amine salt § is reacted with Na. OH to produce the free amine form known as “crack” General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 10
Learning Check Write the equation for ethylamine when it reacts with each of the following: A. H 2 O B. HCl General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 11
Solution Write the equation for ethylamine when it reacts with each of the following: A. B. General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc. 12