Mr. Shields
Functional Groups:
- Carboxylic Acids
- Esters
- Amides
- Aldehydes
- Ketones
- Amines
Regents Chemistry U17 L02
1

Condensed form is written –COOH
– A carbonyl group and a hydroxyl group bonded to same C
– Known as a carboxyl group
– An organic acid
The Carboxyl group is always a terminal functional group
2

Carboxylic acids ionize in water to form a proton and
A carboxylate anion
A Weak Acid
3

The carboxyl group is a terminal group
– no need to give it a number. It’s always on C #1
Drop the –e from the alkane name and add –oic acid
Name this compound:
Butanoic acid
4

Name this compound:
C-C-C-C-C-COOH hexanoic acid
5

- Sharp or noxious smells
- polar molecule that can form 2 hydrogen bonds with themselves or with water
C-C=O
OH
HO
O=C- C
C-C=O
OH O
H
H
This leads to high B.P. and high solubility in water
- 1 st four acids are totally miscible in water
6

Esters are derivatives of Carboxylic acids
– Combination of an Acid and an Alcohol
– The alcohol portion provides the “Alkyl” part of the ester name
7

Esters are not a terminal group but the carbonyl carbon is considered to be C #1
Name the group attached to the hydroxyl oxygen first
(the alkyl group)
Next name the carboxylate carbon chain, dropping the – e and adding –oate
Written condensed format is RCOOR’
8

Esters have distinctive odors (flowers, flavors etc.)
- It’s a f unction of which alcohol is combined with which acid
Alcohol
Ethanol
Pentanol
Octanol
Methanol
Methanol
Acid
Butanoic acid
Ethanoic acid
Ethanoic acid
Salicylic acid
Butanoic acid
Ester
Ethyl butanoate
Pentyl ethanoate
Octyl ethanoate
Methyl salicylate
Methyl butanoate
Fragrance
Pineapple
Banana
Orange wintergreen apple
9

Name this compound:
Name this compound:
CH
3
O
-C-O-CH
2
-CH
2
-CH
2
-CH
3
Ethyl butanoate butyl ethanoate
10

Like esters the amide functional group is a derivative of carboxylic acids
– The -OH is replaced by the amine group
The amide group is a terminal group
Important biological molecules
– Links amino acids together to form proteins
11

-Amides have very high BP’s due to strong H-bonding
-Intermolecular hydrogen bonding possible
- H-bonding can occur between N, H and O
CH
3
– C=O
NH2
BP’s are higher than similar esters and acids
CH
3
COOCH
3
B.P. (deg. C) 57.5
CH
3
COOH
118
CH3CONH
2
221
12

Take the name of the alkane with the same number of carbon atoms
Drop the –e from the alkane name and add –amide
Ethanamide
13

This group is always on a terminal C – so no need to specify location by number
Condensed it is symbolized by a -CHO group at the end of the formula
Aldehydes have characteristic scents and tastes
– Cinnamon, bannana, apple, raspberry flavors are examples
14

To name aldehydes drop the –e from the end of the alkane and add –al; C=O is C #1
Name these two compounds:
Butanal
Methanal
(formaldehyde)
15

Like the aldehydes the Functional group is the carbonyl group C=O
Contains an alkyl group on either side of the C=O
– In aldehydes one side is an alkyl group the other is H
Often used as a solvent
– Acetone is one example
16

Number the C chain so C=O has the lowest #
Drop the final e from the alkane name and add -one
Name these compounds:
2-pentanone
3-hexanone
C-C-C-C-C o
17

Nitrogen is the functional part of an amine
Nitrogen can form three covalent bonds (just like NH
3
)
– One must be to a carbon chain
– The other two bonds can be to Carbon and/or H
2
C-CNH
2 or C-CN-H or
C
C-CN-C
C
18

Like ammonia, amines are polar compounds
And like ammonia, amines are Bronsted-Lowery Bases
- i.e they’re Proton acceptors
H +
H
:N-R
H
19

-Since amines can act as proton acceptors the reaction with a proton donor like HCl leads to an Ionic Compound
HCl +
H
:N-R
H
Cl H
H
:N-R
H
+
20

-Amines can H-bond with water
-Leads to high water solubility up to about 6C
Methyl
Amine v. Sol
Ethyl
Amine
Totally miscible
Propyl
Amine
Totally
Miscible
Butyl
Amine v. sol Sol
(g/100g H
2
0)
-Amines have very strong odors
- Methyl and ethyl amine smells like ammonia
-Higher MW amines often have a fishy smell
-Aromatic amines are generally toxic
-Readily absorbed through skin often with fatal results
21

Need #’s to designate the location of the amine
Name your carbon chain as an alkane, drop the – e and add –amine
2-butanamine
22

Some nasty DIAMINES …Yuk!
23

Related to both amines and acids are the Amino Acids
If you have an “-NH
2 an amino acid
” and a COOH in one molecule it is
GLYCINE
(Gly or G)
Aminoethonaoic acid
Smallest of the
20 amino acids
Commonly
Found in
Proteins
Since the amino group is a proton acceptor and the
Carboxylic acid is a proton donor, amino acids are
Actually NH
3
+ and COO .
24

Alanine (Ala; A)
2-aminopropanoic acid
O
H
3
C-CH-C-OH
NH
2
25