Organic Chemistry

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Organic Chemistry
Functional Groups - Aldehydes - Ketones -
Organic Acids - Esters - Amines - Amides
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Aldehydes

• Group is always on a terminal C no need to
  specify location by number
• Condensed it is symbolized by a -CHO group at the
  end of the formula
• C O is known as a carbonyl group
• Drives the physical and chemical properties of
  these compounds
• Aldehydes have characteristic scents and tastes
• Cinnamon is an example

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Aldehydes

• Drop the e from the end of the alkane and add
  al CO 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 CO
• Contains an alkyl group on either side of the CO
• 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 CO has the lowest
• Drop the final e from the alkane name and add -one

Name these compounds
4-methyl-2-pentanone
3-hexanone
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Properties

• Both aldehydes ketones have
• A carbonyl functional group.
• CO is polar their compounds
• Are polar. This leads to
• Higher B.Ps than non-polar molecules
• Lower than alcohols that can
• H-bond w/ each other
• Can not H-bond between each other
• but can H-bond to solvents like water
• - Lower MW compounds
• are appreciably soluble in water

Propanone Propanal
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Properties
Butane Diethyl ether Propanal Propanone 1-propanol
M.W. 58 58 58 58 60
B.P (deg.C) 0 35 49 56 97
Solubility g/100g H2O Insol. 8 16 Fully miscible Fully miscible
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Organic Acids

• Condensed form is written COOH
• A carbonyl group and a hydroxyl group bonded to C
• Known as a carboxyl group
• A terminal functional group
• The carboxyl group is an organic acid.
• It is the H on the end of COOH that is donated as
  a proton (H)
• What is left is the anion R-COO-

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Carboxylic acids ionize in water to form a proton
and A carboxylate anion
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Naming Organic Acids

• The carboxyl group is a terminal group
• no need to give it a number. Its 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
Butanoic acid
Name this compound
2,4-dimethylhexanoic acid
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Some Common Carboxylic acids
Ethanoic Acid Acetic Acid
Methanoic acid formic acid
The sting of ants
Vinegar
C-C-C-COOH
Butanoic acid
Rancid butter smell
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Physical properties

• Sharp or noxious smells
• polar and can form 2 hydrogen bonds with
  themselves and with water

C-CO OH
HO OC- C
C-CO OH
This leads to high B.P. and high solubility in
water - 1st four acids are totally miscible in
water
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Comparison of properties
Butane Diethyl ether Propanal Propanone 1-propanol ethanoic
M.W. 58 58 58 58 60 60
B.P (deg.C) 0 35 49 56 97 118
Solubility g/100g H2O Insol. 8 16 Fully miscible Fully miscible Fully miscible
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Esters

• Esters are derivatives of Carboxylic acids
• Combination of an Alcohol and an Acid
• The alcohol provides the alkyl portion of the
  ester name
• Esters are polar but can not form hydrogen bonds
  with one another
• BPs of esters are lower than alcohols or acids
  with similar mass

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Physical properties
Butanal Butanone Methyl ethanoate 1-butanol Propanoic Acid
M.W. 72 72 74 74 74
B.P (deg.C) 76 80 57.5 118 141
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Properties
Esters have distinctive odors (flowers, flavors
etc.) - 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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Naming Esters

• Esters are not a terminal group but they are
  unique because of the carboxyl group therefore
  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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Name this compound
Ethyl butanoate
Name this compound
3-methylbutyl ethanoate
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(Not IUPAC)
2-methylbutyl ethanoate
What alcohols and acids produce the above esters?
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(Not IUPAC)
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Amide

• Like esters the amide functional group is a
  derivative of carboxylic acids
• OH 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 BPs due to strong
• intermolecular hydrogen bonding
• - higher than similar esters and acids
• - H-bonding can occur between N, H and O

CH3COOCH3 CH3COOH CH3COONH2
B.P. (deg. C) 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
• Amide carbon is carbon 1 when naming side chaines

Ethanamide
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Name this compound
2-methylpropanamide
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Amines

• Nitrogen is the functional part of an amine
• Nitrogen can form three bonds (just like NH3)
• One must be to the carbon chain
• The other two bonds can be to Carbon and/or H2

C-C-NH2 or Primary Amine
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Physical properties of Amines
Like ammonia, amines are polar compounds
H can also be Carbon Based groups
And like ammonia, amines are Bronsted-Lowery Base
s - both are Proton acceptors
H N-H H
H
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Physical properties of Amines
- Since amines can act as proton acceptors
reaction With a proton donor like HCl will lead
to a salt, i.e. an ionic compound
HCl
Cl- H
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Physical Properties of Amines
Amines can hydrogen bond like alcohols or
Carboxylic acids - Contains N and H - H-bonding
raises the B.P. but it is not as high as the
alcohols or acids
H C-C-N H
Ethanoic acid Ethanol Ethyl amine
B.P. (deg C) 118 78 17
H N-C-C H
Tertiary amines have higher BPs than secondary
and secondary is higher than primary
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Physical properties of Amines

• Amines can H-bond with water
• Leads to high water solubility up to about 6C

Methyl Amine Ethyl Amine Propyl Amine Butyl Amine
Sol (g/100g H20) 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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Amines

• Need s to designate the location of the amine
• Name your carbon chain as an alkane, drop the e
  and add amine
• If there are 2 amines indicate their location and
  add diamine to the alkane name

2-butanamine
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Name this compound
C-C-C-C-C-C N N
1,3-hexadiamine
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Amino Acids
Related to amines are the Amino Acids

• If you have a N and a COOH it is an amino acid

GLYCINE
Since the amino group is a proton acceptor and
the Carboxylic acid is a proton donor amino acids
are Actually NH3 and COO-.