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914 CHAPTER 22 22.3. (a) This compound is an amine that has only one simple alkyl group (13 carbons is a tridecyl group) connected to the nitrogen atom, so we can name this compound as an alkyl amine or an alkanamine. Therefore, this compound can be named tridecylamine or 1-tridecanamine. (b) The parent is a four-carbon carboxylic acid (butanoic acid). The NH2 group is called an amino group. The carboxylic acid functionality has a higher suffix priority than amines, therefore, this compound is named 4-aminobutanoic acid. (c) This compound has two amine groups and is named as a diamine (similar to a compound with two hydroxyl groups being named as a diol). The amino groups are at positions 1 and 5 of a five-carbon chain so it is named pentane-1,5-diamine. H2N NH2 Pentane-1,5-diamine 53 42 1 22.4. The primary amine has two N-H bonds and is expected to exhibit the highest extent of hydrogen bonding, and therefore, the highest boiling point. The tertiary amine lacks N-H bonds, and is therefore expected to have the lowest boiling point. 22.5. (a) This amine has more than five carbon atoms per amino group (there are eight carbon atoms and only one amino group). Therefore, this compound is not expected to be water soluble. (b) This amine has fewer than five carbon atoms per amino group (there are only three carbon atoms and one amino group). Therefore, this compound is expected to be water soluble. (c) This diamine has fewer than five carbon atoms per amino group (there are six carbon atoms and two amino groups). Therefore, this compound is expected to be water soluble. 22.6. (a) The following compound is expected to be a stronger base because the lone pair is localized, and therefore more available to function as a base. The other compound exhibits a delocalized lone pair, and is therefore a weaker base. (b) The following compound is expected to be a stronger base because the lone pair is not participating in aromaticity. It is available to function as a base. In contrast, the other compound is aromatic, and the lone pair is delocalized (in order to establish aromaticity), so it is unavailable to function as base. (c) The following compound is expected to be a stronger base because the nitrogen atom has a lone pair that is localized, and therefore more available to function as a base. The other compound exhibits a nitrogen atom with a delocalized lone pair, and is therefore a weaker base. (d) The following compound is expected to be a stronger base because the lone pair is not participating in aromaticity. The lone pair occupies an sp2 hybridized orbital (directed away from the ring, in the plane of the ring) and is available to function as a base. In contrast, the other compound (shown in the problem statement) exhibits a nitrogen atom with a lone pair that is highly delocalized (in order to establish aromaticity in the five-membered ring), so it is unavailable to function as base. 22.7. In all of these compounds, the lone pair (on the nitrogen atom) is delocalized throughout two aromatic rings: www.MyEbookNiche.eCrater.com