Announcements & Agenda (03/02/07)
Welcome Visitors! Please make yourselves
comfortable; we will start with a quiz 
Mid-term grades are only based on lecture
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I will give you detailed grade sheets on Monday
Note: most of MT grade was based on Exam 1
You should read Ch 11/12 this weekend!
Today
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Functional groups in organic chemistry (10.5)
Unsaturated compounds (11.1)
Cis-trans isomers (11.2)
Reactivity of unsaturated compounds (11.3)
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Last Time: Organic Compounds
Typical organic compounds
• have covalent bonds.
• have low melting points.
• have low boiling points.
• are flammable.
• are soluble in nonpolar
solvents.
• are usually not soluble in
water.
oil (organic) and water (inorganic)
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Last Time: Alkanes (CnH2n+2)
•
•
•
•
•
nonpolar.
insoluble in water.
less dense than water.
flammable in air.
not a lot of interesting
chemistry!
• …but they burn!
3
Last Time: Intermolecular ForcesBP Increases w/ Increasing Size 
Melting (blue) and boiling (pink) points of
the first 14 n-alkanes in °C.
4
Last Time: 4 Ways to Represent Structures
of Organic Compounds (Know These!)
1.
2.
3.
4. Line Structures
- See next slide
5
Last Time: Naming Alkanes
Give the name of
STEP 1
CH3 CH3


CH3─CH─CH─CH3
Name the longest continuous chain.
CH3 CH3


CH3─CH─CH─CH3
butane
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Last Time: Naming Alkanes
Give the name of
CH3 CH3


CH3─CH─CH─CH3
STEP 2
Number chain. CH3 CH3


CH3─CH─CH─CH3
1
2
3 4
STEP 3 Locate substituents and name
(alphabetically).
2,3-dimethylbutane
7
Functional Groups (Beyond Single
Bonds and Only C & H)
• a characteristic feature of org. molecules
that behave in a predictable way.
• composed of an atom or group of atoms.
• groups that replace a hydrogen atom in
the corresponding alkane.
• a way to classify families of organic
compounds.
Key Point: Functional Groups Give the
Molecule their Chemical Personality
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Functional Groups (Beyond Single
Bonds and Only C & H)
• a characteristic feature of org. molecules
that behave in a predictable way.
• composed of an atom or group of atoms.
• groups that replace a hydrogen atom in
the corresponding alkane.
• a way to classify families of organic
compounds.
Key Point: Differences typically depend
on polarity!!!
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Alkenes and Alkynes
Alkenes contain a
double bond
between adjacent
carbon atoms.
Alkynes contain a
triple bond.
10
Alcohols and Ethers
An alcohol contains
the hydroxyl (-OH)
functional group.
In an ether, an
oxygen atom is
bonded to two
carbon atoms.
–C–O–C– .
11
Aldehydes and Ketones
An aldehyde contains a
carbonyl group (C=O),
which is a carbon atom
with a double bond to an
oxygen atom.
In a ketone, the carbon of
the carbonyl group is
attached to two other
carbon atoms.
12
Carboxylic Acids and Esters
Carboxylic acids contain
the carboxyl group, which is
a carbonyl group attached
to a hydroxyl group.
O
║
— C—OH
An ester contains the
carboxyl group between
carbon atoms.
13
Amines and Amides
In amines, the
functional group is a
nitrogen atom.
|
—N —
In amides, the hydroxyl
group of a carboxylic
acid is replaced by a
nitrogen group.
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Summary 
These are some of the most important
biological functional groups!
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Some functional groups in
consumer products
BENGAY
 Camphor – a ketone
 Menthol – an alcohol
 Methyl salicylate – an ester and a phenol
Neopsporin
 Miconazole – many functional groups
(ether, chloro)
 Dimethyl ether propellant
Halls cough
 Menthol- an alcohol
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Some functional groups in spices
Nutmeg
 Myristicin – a polyether, an alkene, benzene
ring
 Elemicin
 Safrole
Anise
 Anethole – an ether, an alkene, benzene ring
Caraway seeds
 d-Carvone – a ketone
Spearmint
 l-Carvone – a ketone
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Ch. 11 Unsaturated Hydrocarbons
Alkenes & Alkynes
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15 Good Practice Problems (Ch 11)
11.05, 11.07, 11.11, 11.13, 11.15,
11.17, 11.19, 11.23, 11.25, 11.27,
11.29, 11.31, 11.35, 11.37, 11.40
For Ch 10 – Do all odd problems!
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Saturated Hydrocarbons
• have the maximum # of H atoms attached to
each C atom.
• i.e. alkanes with single C-C bonds, CnH2n+2
• Examples:
propane:
CH3—CH2—CH3
(C3H8)
2-methyl propane: CH3—CH—CH3 (C4H10)
│
CH3
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Unsaturated Hydrocarbons
• have fewer H atoms
attached to the C chain
than alkanes
• are alkenes with double
bonds
•
•
If one C=C bond, CnH2n
Monounsaturated = 1 D.B.
are alkynes with triple
bonds
•
If one C≡C bond, CnH2n-2
NOTE: cycloalkanes can also be thought of as
unsaturated b/c they have the formula (CnH2n)
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FUN WITH KETCHUP
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Unsaturated compounds are oxidized
relative to saturated compounds
Oxidation of organic compounds means:

Replacement of hydrogen atom with a more
electronegative atom (oxygen or nitrogen)
OR

Loss of H atoms & replacement with a double
bond
23
Ethene (Ethylene)
Ethene or ethylene
• is an alkene with the formula
C2H4.
• has two carbon atoms
connected by a double bond.
• has two H atoms bonded to
each C atom.
• is flat with all the C and H
atoms in the same plane.
• is used to accelerate the
ripening of fruits.
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1-Methylcyclopropene (1-MCP)
http://www.smartfresh.com/
It inhibits the release of ethylene, thus
preventing ripening.
CH3
1-MCP
25
Naming Simple Alkenes
• use the corresponding alkane name.
• change the ending to –ene
Alkene
IUPAC
Common
H2C=CH2
ethene
ethylene
H2C=CH─CH3
propene
propylene
cyclohexene
26
Naming Simple Alkynes
• use the corresponding alkane name.
• change the ending to –yne.
Alkyne
IUPAC
Common
HC≡CH
ethyne
acetylene
HC≡C─CH3
propyne
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Bond Angles in Alkenes & Alkynes
According to VSEPR theory:
• the 3 groups bonded to C
atoms in a double bond are
at 120° angles.
• alkenes are flat because the
atoms in a double bond all
lie in the same plane.
• the 2 groups bonded to
each carbon in a triple bond
are at 180° angles.
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How do you make a double bond?
The 1st bond is made by “orbitals” overlapping
between atoms, and is called a “sigma” (σ) bond.
The 2nd bond is made by sideways p orbitals
(not directly between the atoms) and is called a
“pi” (π) bond.
This is why a single bond can rotate. But the π
bond part of a double bond can’t rotate – you’d
have to break it.
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More Steroisomers: Cis-Trans Isomers
In an alkene, the double bond
• is rigid, i.e. NO ROTATION around the double bond!
• holds attached groups in fixed positions.
• makes cis/trans isomers possible.
• Important in nature – such as in pheromones
CH3
CH3
CH = CH
cis
CH3
CH = CH
trans
CH3
(similar groups on same side) (similar groups on opp. sides)30
Cis-Trans Isomerism
• Alkenes cannot have cis-trans isomers if a C
atom in the double bond is attached to identical
groups.
Identical
Identical
HH
Br
H
Br
C C
HH
Br
H
C C
CH3
2-bromopropene
(not cis or trans)
H
Br
1,1-dibromoethene
(not cis or trans)
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Unsaturated Fatty Acids
 Fatty acids in vegetable oils are omega-6 acids (the
first double bond occurs at carbon 6 counting from
the methyl group)
 A common omega-6 acid is linoleic acid
CH3CH2CH2CH2CH2CH=CHCH2CH=CH(CH2)7COOH
6
an alkene group
linoleic acid, a fatty acid
a carboxylic acid
group
32
Trans Fats
In vegetable oils, the unsaturated fats usually
contain cis double bonds.
• During hydrogenation, some cis double bonds
are converted to trans double bonds (more
stable) causing a change in the fatty acid
structure.
• If a label states “partially” or “fully
hydrogenated”, the fats contain trans fatty
acids.
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