Download Benzene

20.8 Aromatic Hydrocarbons
- 6 carbon ring w/double bonds
-”benzene ring”
- smell nice (cinnamon and vanilla)
-different than cyclo- hydrocarbons
Cyclohexane
Puckered
109.5o <‘s
More H
Saturated
Benzene
Flat
120o <‘s
Fewer H
Unsaturated
Figure 20.8: Two Lewis
structures for the benzene ring.
Figure 20.8: Shorthand notation
for benzene rings.
Figure 20.9: The bonding in the
benzene ring is a combination of
different Lewis structures.
Figure 20.10:
Names of some
common
monosubstituted
benzenes.
20.10 Functional Groups
 Hydrocarbon
derivatives = primarily
HC’s but have additional atoms or
groups of atoms called functional
groups. A functional group is a
reactive portion of a molecule that
undergoes predictable reactions.
Common functional groups
 alcohols
 ethers
 aldehydes
 ketones
 carboxylic
 esters
acids
alcohol
 hydroxyl
group (-OH)
Some examples are
CH3 OH
CH3 CH2 OH
methanol
ethanol
Methanol = gasoline
Ethanol = alcohol beverage
Isopropyl = rubbing alcohol
OH
CH3
CH
CH3
2-propanol
ether
 oxygen
“bridge”
An example is
CH3 CH2 O CH2 CH3
diethyl ether
(This is the most common ether, often called simply
ether, used as an anesthetic.)
carboxylic acid
 carboxyl
group, -COOH
An example is
O
CH3
C
OH
ethanoic acid
ester
 compound
formed from a carboxylic
acid, RCOOH, and an alcohol, R’OH.
The general structure is
O
R
C
O
R'
aldehyde
 carbonyl
group (C=O) with at least
one H atom.
An example is
O
CH3 CH
ethanal
ketone
 carbonyl
group with two hydrocarbon
An example is
O
CH3 CH2 C CH3
2-butanone