Organic Chemistry
Chapter 12
Copyright ? The McGraw-Hill Companies,Inc,Permission required for reproduction or display.
? Carbon atoms have the ability to link
together and form molecules made up of
many carbon atoms.
? The branch of chemistry that is the study
of carbon-containing compounds is known
as organic chemistry (有机化学 ).
? 13 million known organic compounds and
100,000 new ones are added annually.
? Only 200,000-300,000 known inorganic
compounds.
12.1 Hydrocarbons (碳氢化合物、烃 ) contain only
carbon and hydrogen
? Hydrocarbons differ from each other by the
number of carbon atoms.
methane CH4 Octane C8H18 polyethylene
? Hydrocarbons differ from each other also by the way carbon atoms
connect to each other,Straight-chain hydrocarbon,branched
hydrocarbon
? Molecules having the same chemical formula but different structures
are called structural isomers (结构异构体 ),Structural isomers have
different physical and chemical properties,The number of possible
structural isomers for a chemical formula increases rapidly as the
number of carbon atoms increases,3 for C5H12,18 for C8H18,75 for
C10H22,366,319 for C20H42.
n-pentane iso-pentane Neo- pentane
C
H
H
H
C C C C
H
H H
H
H
H H
H
HC
H
H
H
C C C H
C H 3
H H
H
H
H
C
H
H
H
C C H
C H 3
C H 3 H
H
Carbon-based molecules can have different spatial
orientations called conformations (构象 ).
Fig12.2 three conformation for a molecule of n-pentane,The
molecule looks different in each conformation,but the five-carbon
framework is the same in all three conformations,In a sample of
liquid n-pentane,the molecules are found in all conformations- not
unlike a bucket of worms
Hydrocarbons are usually from crude oil by
fractional distillation (分馏 ).
Fig12.3 a
schematic for
the fractional
distillation of
petroleum into
its useful
hydrocarbon
components
12.2 Unsaturated hydrocarbons (不饱和烃 ) contain
multiple bonds
CH3 CH CH CH3
2-butene
Unsaturated hydrocarbonsaturated hydrocarbon
CH3－ CH2－ CH2 － CH3
n-butane
Benzene (苯 ) and aromatic compounds (芳香化合物 )
Fig 12.8 (a) the double bonds of benzene,C6H6,are able to
migrate around the ring,(b) for this reason,they are often
represented by a circle within the ring
(a) (b)
toluene naphthalene 1,4-dichlorobenzene
C l
C l
12.3 Organic molecules are classified by functional
group (官能团 )
? 醇、酚、醚、
胺、酮、醛、
酰胺、羧酸、
酯
Alcohols contain the hydroxyl group (羟基 )
? Methanol,11 billion pounds were produced annually in USA,Mainly
used as solvent and for the preparation of formaldehyde (甲醛 ) and
formic acid (甲酸 ),Ingesting only about 15ml will lead to blindness,
30ml will lead to death.
? Ethanol,produced by biological method (fermentation,发酵 ) or
chemical method.
? The liquid produced by fermentation has an ethanol concentration no
more than about 12 percent because at this concentration the yeast
begin to die.
Fig 12.11 ethanol can be synthesized from the unsaturated
hydrocarbon ethene,with phosphoric acid as a catalyst
Phenols contain an acidic hydroxyl group
? Phenol has antiseptic value,but damages
healthy tissue.
O
H
O + H +
Phenoxide ionPhenol(acidic) Hydrogen ion
O O O O
Fig 12.12 the negative charge of the phenoxide ion is able to migrate to
select positions on the benzene ring,This mobility helps to
accommodate the negative charge,which is why the phenolic group
readily donates a hydrogen ion
The oxygen of ether group is bonded to two
carbon atoms
? Ethers have lower boiling points and lower solubility in water than
the corresponding ethanol due to the weaker interaction between
each other and with water.
C
O
C
H
H H H
H
H
Ethanol,soluble in water,
boiling point 78oC
Dimethyl ether,insoluble in
water,boiling point -25oC
Fig12.14 the oxygen in an
alcohol such as ethanol is
bonded to one carbon atom
and one hydrogen atom,The
oxygen in an ether such as
dimethyl ether is bonded to
two carbon atoms,Because of
these difference,alcohols and
ethers of similar molecular
mass have vastly different
physical properties
Diethyl ether,boiling point -25oC
Fig12.15 Diethyl ether is the systematic name for the
“ether” historically used as an anesthetic
Amines form alkaline solutions
H 2 N N H 2
Putrescine (1,4-butanediamine) Cadaverine(1,5-pentanediamine)
N H 2H 2 N
Fig 12.16 low-formula-mass amines like
these tend to have an offensive odor
N
N N
N
O
O
H 3 C
C H 3
C H 3
+ H3PO4
N
N N
N
O
O
H 3 C
C H 3
C H 3
H
H 2 P O 4
caffeine-phosphoric acid salt
(water-soluble)Caffeine free-base form (water-soluble) Phosphoric acid
Fig12.18 all alkaloids are bases that react with acids to form salts,An
example is the alkaloid caffeine,shown here reacting with phosphoric
acid
Fig12.19 tannins are responsible for the
brown stains in coffee mugs or on a coffee
drinker’s teeth,Because tannins are acidic,
they can be readily removed with an alkaline
cleanser,Use a little laundry bleach on the
mug,and brush your teeth with baking soda
? Ketones,aldehydes,amides,carboxylic acids and esters
all contain a carbonyl group
? Many aldehydes are particularly fragrant,The smells of
lemons,cinnamon (肉桂 ),almond (杏仁 ),and vanilla are
due to the aldehydes citral (柠檬醛 ),cinnamaldehyde (肉
桂醛 ),benzaldehyde （苯甲醛） and vanillin (香草醛 ).
C H 3
C
H
H 3 C C H 3
O
C
H
O C H
O
C
O C H 3
O H
O
H
vanillinbenzaldehyde
cinnamonaldehyde
citra
Fig 12.21 aldehydes are responsible for many familiar fragrances
Amide
N
C
O
Amide group
N
C H 2 C H 3
C H
2
C H
3
O
C H 3
Fig12.22 N,N-
diethyl-m-
toluamide is
an example
of an amide,
Amides
contain the
amide group,
shown
hoghlighted
in blue
N,N-diethyl-m-toluamide (DEET)
? Carboxylic acids are weak acids.
? Salicylic acid (水杨酸 ) and acetylsalicylic acid
(乙酰水杨酸 )
O H
O
O
O
Carboxyl
group
ester
Carboxylic acids
acetylsalicylic acid
O H
O
O H
Carboxyl
group
Phenolic
group
Fig12.24 (a) salicylic acid,
found in the bark of the willow
tree,is an example of a
molecule containing both a
carboxyl group and a phenolic
group,(b) Aspirin,
acetylsalicylic acid,is less
acidic than salicylic acid
because it no longer contains
the acidic phenolic group,
which has been concerted to
an ester
(a)
(b)
Esters have notable fragrances
structure Name flavor
Ethyl formate rum
Isopentyl acetate banana
Octyl acetate orange
Ethyl butyrate pineapple
methyl butyrate apple
Isobutyl formate raspberry
Methyl salicylate wintergreen
O
CH
C H 2 C H 3
O
O
C
O
C H 3C H 3 C H 2 C H 2 C H 2
O
C
H
O
C H 2 C
C H 3
H
C H 3
C H 3O
O
O
C
O
C H 3C H 3 C H 2 C H 2
O
C
C H 2 ( C H 2 ) 6
O
H 3 C C H
3
O
C
C H 2 C H 2
O
H 3 C C
C H 3
H
C H 3
Table12.4
some
esters
and their
flavors
12.4 Organic molecules can link to form polymers
Polymers (聚合物 ) are exceedingly long molecules
that consist of repeating molecular units called
monomers (单体 ),Two major types of synthetic
polymers,addition polymers (加聚型聚合物 ) and
condensation polymers (缩聚型聚合物 )
polymer
monomer
Fig 12.25 a polymer is a long molecule consisting of many
smaller monomer molecules linked together
Addition polymers result from the joining together
of monomers
Ethylene
monomer
polyethylene
polymerization
Fig 12.26 the addition
polymer polyethylene is
formed as electrons
from the double bonds
of ethylene monomer
molecules split away
and become unpaired
valence electrons,Each
unpaired electron them
joins with an unpaired
electron of a
neighboring carbon
atom to form a new
covalence bond that
links monomer units
together
Table12.5
HDPE and LDPE
(a) Molecular strands of HDPE (b) Molecular strands of LDPE
Fig12.27 (a) the polyethylene strands of HDPE are able to pack
closely together,much like strands of uncooked spaghetti,(b)
the polyethylene strands of LDPE are branched,which prevents
the strands from packing well
Condensation polymers form with the loss of small
molecules
Nylon 66
Adipic acid
Adipic acid
polymerization
Nylon
Hexamethylenediamine
Reactive ends
Hexamethylenediamine
Fig12.33 adipic acid and hexamethylenediamine
polymerize to form the condensation copolymer nylon
Polyethylene terephthalate
Terephthalic
acid
Ethylene
glycol
polymerization
Polyethylene terephthalate (pet)
Fig12.34 Terephthalic acid and Ethylene glycol Polymerize to
form the condensation copolymer Polyethylene terephthalate
Thermoplastic (热塑性 ) and thermoset (热固性 )
polymers
polymerization
Three reactive ends
formaldehyde
melamine
melmac
Fig 12.35 the three
reactive groups of
melamine allow it
to polymerize with
formaldehyde to
form a three-
dimensional
network
Functional Polymers
Fig12.36 flexible
and flat video
displays can now
be fabricated
from polymers
Chapter 12
Copyright ? The McGraw-Hill Companies,Inc,Permission required for reproduction or display.
? Carbon atoms have the ability to link
together and form molecules made up of
many carbon atoms.
? The branch of chemistry that is the study
of carbon-containing compounds is known
as organic chemistry (有机化学 ).
? 13 million known organic compounds and
100,000 new ones are added annually.
? Only 200,000-300,000 known inorganic
compounds.
12.1 Hydrocarbons (碳氢化合物、烃 ) contain only
carbon and hydrogen
? Hydrocarbons differ from each other by the
number of carbon atoms.
methane CH4 Octane C8H18 polyethylene
? Hydrocarbons differ from each other also by the way carbon atoms
connect to each other,Straight-chain hydrocarbon,branched
hydrocarbon
? Molecules having the same chemical formula but different structures
are called structural isomers (结构异构体 ),Structural isomers have
different physical and chemical properties,The number of possible
structural isomers for a chemical formula increases rapidly as the
number of carbon atoms increases,3 for C5H12,18 for C8H18,75 for
C10H22,366,319 for C20H42.
n-pentane iso-pentane Neo- pentane
C
H
H
H
C C C C
H
H H
H
H
H H
H
HC
H
H
H
C C C H
C H 3
H H
H
H
H
C
H
H
H
C C H
C H 3
C H 3 H
H
Carbon-based molecules can have different spatial
orientations called conformations (构象 ).
Fig12.2 three conformation for a molecule of n-pentane,The
molecule looks different in each conformation,but the five-carbon
framework is the same in all three conformations,In a sample of
liquid n-pentane,the molecules are found in all conformations- not
unlike a bucket of worms
Hydrocarbons are usually from crude oil by
fractional distillation (分馏 ).
Fig12.3 a
schematic for
the fractional
distillation of
petroleum into
its useful
hydrocarbon
components
12.2 Unsaturated hydrocarbons (不饱和烃 ) contain
multiple bonds
CH3 CH CH CH3
2-butene
Unsaturated hydrocarbonsaturated hydrocarbon
CH3－ CH2－ CH2 － CH3
n-butane
Benzene (苯 ) and aromatic compounds (芳香化合物 )
Fig 12.8 (a) the double bonds of benzene,C6H6,are able to
migrate around the ring,(b) for this reason,they are often
represented by a circle within the ring
(a) (b)
toluene naphthalene 1,4-dichlorobenzene
C l
C l
12.3 Organic molecules are classified by functional
group (官能团 )
? 醇、酚、醚、
胺、酮、醛、
酰胺、羧酸、
酯
Alcohols contain the hydroxyl group (羟基 )
? Methanol,11 billion pounds were produced annually in USA,Mainly
used as solvent and for the preparation of formaldehyde (甲醛 ) and
formic acid (甲酸 ),Ingesting only about 15ml will lead to blindness,
30ml will lead to death.
? Ethanol,produced by biological method (fermentation,发酵 ) or
chemical method.
? The liquid produced by fermentation has an ethanol concentration no
more than about 12 percent because at this concentration the yeast
begin to die.
Fig 12.11 ethanol can be synthesized from the unsaturated
hydrocarbon ethene,with phosphoric acid as a catalyst
Phenols contain an acidic hydroxyl group
? Phenol has antiseptic value,but damages
healthy tissue.
O
H
O + H +
Phenoxide ionPhenol(acidic) Hydrogen ion
O O O O
Fig 12.12 the negative charge of the phenoxide ion is able to migrate to
select positions on the benzene ring,This mobility helps to
accommodate the negative charge,which is why the phenolic group
readily donates a hydrogen ion
The oxygen of ether group is bonded to two
carbon atoms
? Ethers have lower boiling points and lower solubility in water than
the corresponding ethanol due to the weaker interaction between
each other and with water.
C
O
C
H
H H H
H
H
Ethanol,soluble in water,
boiling point 78oC
Dimethyl ether,insoluble in
water,boiling point -25oC
Fig12.14 the oxygen in an
alcohol such as ethanol is
bonded to one carbon atom
and one hydrogen atom,The
oxygen in an ether such as
dimethyl ether is bonded to
two carbon atoms,Because of
these difference,alcohols and
ethers of similar molecular
mass have vastly different
physical properties
Diethyl ether,boiling point -25oC
Fig12.15 Diethyl ether is the systematic name for the
“ether” historically used as an anesthetic
Amines form alkaline solutions
H 2 N N H 2
Putrescine (1,4-butanediamine) Cadaverine(1,5-pentanediamine)
N H 2H 2 N
Fig 12.16 low-formula-mass amines like
these tend to have an offensive odor
N
N N
N
O
O
H 3 C
C H 3
C H 3
+ H3PO4
N
N N
N
O
O
H 3 C
C H 3
C H 3
H
H 2 P O 4
caffeine-phosphoric acid salt
(water-soluble)Caffeine free-base form (water-soluble) Phosphoric acid
Fig12.18 all alkaloids are bases that react with acids to form salts,An
example is the alkaloid caffeine,shown here reacting with phosphoric
acid
Fig12.19 tannins are responsible for the
brown stains in coffee mugs or on a coffee
drinker’s teeth,Because tannins are acidic,
they can be readily removed with an alkaline
cleanser,Use a little laundry bleach on the
mug,and brush your teeth with baking soda
? Ketones,aldehydes,amides,carboxylic acids and esters
all contain a carbonyl group
? Many aldehydes are particularly fragrant,The smells of
lemons,cinnamon (肉桂 ),almond (杏仁 ),and vanilla are
due to the aldehydes citral (柠檬醛 ),cinnamaldehyde (肉
桂醛 ),benzaldehyde （苯甲醛） and vanillin (香草醛 ).
C H 3
C
H
H 3 C C H 3
O
C
H
O C H
O
C
O C H 3
O H
O
H
vanillinbenzaldehyde
cinnamonaldehyde
citra
Fig 12.21 aldehydes are responsible for many familiar fragrances
Amide
N
C
O
Amide group
N
C H 2 C H 3
C H
2
C H
3
O
C H 3
Fig12.22 N,N-
diethyl-m-
toluamide is
an example
of an amide,
Amides
contain the
amide group,
shown
hoghlighted
in blue
N,N-diethyl-m-toluamide (DEET)
? Carboxylic acids are weak acids.
? Salicylic acid (水杨酸 ) and acetylsalicylic acid
(乙酰水杨酸 )
O H
O
O
O
Carboxyl
group
ester
Carboxylic acids
acetylsalicylic acid
O H
O
O H
Carboxyl
group
Phenolic
group
Fig12.24 (a) salicylic acid,
found in the bark of the willow
tree,is an example of a
molecule containing both a
carboxyl group and a phenolic
group,(b) Aspirin,
acetylsalicylic acid,is less
acidic than salicylic acid
because it no longer contains
the acidic phenolic group,
which has been concerted to
an ester
(a)
(b)
Esters have notable fragrances
structure Name flavor
Ethyl formate rum
Isopentyl acetate banana
Octyl acetate orange
Ethyl butyrate pineapple
methyl butyrate apple
Isobutyl formate raspberry
Methyl salicylate wintergreen
O
CH
C H 2 C H 3
O
O
C
O
C H 3C H 3 C H 2 C H 2 C H 2
O
C
H
O
C H 2 C
C H 3
H
C H 3
C H 3O
O
O
C
O
C H 3C H 3 C H 2 C H 2
O
C
C H 2 ( C H 2 ) 6
O
H 3 C C H
3
O
C
C H 2 C H 2
O
H 3 C C
C H 3
H
C H 3
Table12.4
some
esters
and their
flavors
12.4 Organic molecules can link to form polymers
Polymers (聚合物 ) are exceedingly long molecules
that consist of repeating molecular units called
monomers (单体 ),Two major types of synthetic
polymers,addition polymers (加聚型聚合物 ) and
condensation polymers (缩聚型聚合物 )
polymer
monomer
Fig 12.25 a polymer is a long molecule consisting of many
smaller monomer molecules linked together
Addition polymers result from the joining together
of monomers
Ethylene
monomer
polyethylene
polymerization
Fig 12.26 the addition
polymer polyethylene is
formed as electrons
from the double bonds
of ethylene monomer
molecules split away
and become unpaired
valence electrons,Each
unpaired electron them
joins with an unpaired
electron of a
neighboring carbon
atom to form a new
covalence bond that
links monomer units
together
Table12.5
HDPE and LDPE
(a) Molecular strands of HDPE (b) Molecular strands of LDPE
Fig12.27 (a) the polyethylene strands of HDPE are able to pack
closely together,much like strands of uncooked spaghetti,(b)
the polyethylene strands of LDPE are branched,which prevents
the strands from packing well
Condensation polymers form with the loss of small
molecules
Nylon 66
Adipic acid
Adipic acid
polymerization
Nylon
Hexamethylenediamine
Reactive ends
Hexamethylenediamine
Fig12.33 adipic acid and hexamethylenediamine
polymerize to form the condensation copolymer nylon
Polyethylene terephthalate
Terephthalic
acid
Ethylene
glycol
polymerization
Polyethylene terephthalate (pet)
Fig12.34 Terephthalic acid and Ethylene glycol Polymerize to
form the condensation copolymer Polyethylene terephthalate
Thermoplastic (热塑性 ) and thermoset (热固性 )
polymers
polymerization
Three reactive ends
formaldehyde
melamine
melmac
Fig 12.35 the three
reactive groups of
melamine allow it
to polymerize with
formaldehyde to
form a three-
dimensional
network
Functional Polymers
Fig12.36 flexible
and flat video
displays can now
be fabricated
from polymers
