Transcript carbonyl group

Functional Groups:
- Carboxylic Acids
- Esters
- Amides
- Aldehydes
- Ketones
- Amines
Mr. Shields
Regents Chemistry
U17 L02
1
Organic Acids
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
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Carboxylic acids ionize in water to form a proton and
A carboxylate anion
A Weak Acid
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Naming Organic Acids
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
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Naming Organic Acids
Name this compound:
C-C-C-C-C-COOH
hexanoic acid
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Physical properties
- 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
- 1st four acids are totally miscible in water
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Esters
Esters are derivatives of Carboxylic acids
– Combination of an Acid and an Alcohol
– The alcohol portion provides the “Alkyl” part of the ester
name
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Naming Esters
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’
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Properties
Esters have distinctive odors (flowers, flavors etc.)
- It’s a function of which alcohol is combined with
which acid
Alcohol
Acid
Ester
Fragrance
Ethanol
Butanoic acid
Ethyl butanoate
Pineapple
Pentanol
Ethanoic acid
Pentyl ethanoate
Banana
Octanol
Ethanoic acid
Octyl ethanoate
Orange
Methanol
Salicylic acid
Methyl salicylate
wintergreen
Methanol
Butanoic acid
Methyl butanoate
apple
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Name this compound:
Ethyl butanoate
Name this compound:
O
CH3-C-O-CH2-CH2-CH2-CH3
butyl ethanoate
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Amide
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
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Amide Physical Properties
-Amides have very high BP’s due to strong H-bonding
-Intermolecular hydrogen bonding possible
- H-bonding can occur between N, H and O
CH3 – C=O
NH2
- BP’s are higher than similar esters and acids
B.P. (deg. C)
CH3COOCH3
CH3COOH
CH3CONH2
57.5
118
221
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Amide
Take the name of the alkane with the same number
of carbon atoms
Drop the –e from the alkane name and add –amide
Ethanamide
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Aldehydes
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
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Aldehydes
To name aldehydes drop the –e
from the end of the alkane and
add –al; C=O is C #1
Name these two compounds:
Methanal
(formaldehyde)
Butanal
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Ketones
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
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Naming Ketones
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
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Amines
Nitrogen is the functional part of an amine
Nitrogen can form three covalent bonds (just like NH3)
– One must be to a carbon chain
– The other two bonds can be to Carbon and/or H2
C-C-NH2 or C-C-N-H or
C
C-C-N-C
C
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Physical properties of Amines
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
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Physical properties of Amines
-Since amines can act as proton acceptors the
reaction with a proton donor like HCl leads to
an Ionic Compound
H
HCl + :N-R
H
H
Cl- H :N-R +
H
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Physical properties of Amines
-Amines can H-bond with water
-Leads to high water solubility up to about 6C
Sol
(g/100g H20)
Methyl
Amine
Ethyl
Amine
Propyl
Amine
Butyl
Amine
v. Sol
Totally
miscible
Totally
Miscible
v. sol
-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
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Naming Amines
Need #’s to designate the location of the amine
Name your carbon chain as an alkane, drop the –
e and add –amine
2-butanamine
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Some nasty DIAMINES …Yuk!
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Amino Acids
Related to both amines and acids are the Amino Acids
If you have an “-NH2” and a COOH in one molecule it is
an amino acid
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 NH3+ and COO-.
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Another Amino Acid
Alanine (Ala; A)
2-aminopropanoic acid
O
H3C-CH-C-OH
NH2
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