Organic Chemistry I: Compounds - PowerPoint PPT Presentation

Loading...

PPT – Organic Chemistry I: Compounds PowerPoint presentation | free to download - id: 6c602c-NjUxY



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Organic Chemistry I: Compounds

Description:

Chapter 25 Organic Chemistry I: Compounds – PowerPoint PPT presentation

Number of Views:159
Avg rating:3.0/5.0
Slides: 164
Provided by: Charl262
Learn more at: http://www.ahsd.org
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Organic Chemistry I: Compounds


1
Chapter 25
  • Organic Chemistry I Compounds

2
Chapter Goals
  • Saturated Hydrocarbons
  • Alkanes and Cycloalkanes
  • Naming Saturated Hydrocarbons
  • Unsaturated Hydrocarbons
  • Alkenes
  • Alkynes
  • Aromatic Hydrocarbons
  • Benzene
  • Other Aromatic Hydrocarbons
  • Hydrocarbons A Summary

3
Chapter Goals
  • Functional Groups
  • Organic Halides
  • Alcohols and Phenols
  • Ethers
  • Aldehydes and Ketones
  • Amines
  • Carboxylic Acids
  • Some Derivatives of Carboxylic Acids
  • Summary of Functional Groups

4
Chapter Goals
  • Fundamental Classes of
  • Organic Reactions
  • Substitution Reactions
  • Addition Reactions
  • Elimination Reactions
  • Polymerization Reactions

5
Saturated Hydrocarbons
  • Hydrocarbons are chemical compounds that contain
    only C and H atoms.
  • Saturated hydrocarbons contain only single or
    sigma (?) bonds.
  • There are no double or triple bonds in these
    compounds.
  • The primary source of hydrocarbons is petroleum
    and natural gas.

6
Alkanes and Cycloalkanes
  • The simplest saturated hydrocarbons are called
    alkanes.
  • Methane, CH4, is the simplest alkane.
  • The alkanes form a homologous series.
  • Each member of the series differs by a specific
    number and kind of atoms.

7
Alkanes and Cycloalkanes
  • The alkanes differ from each other by a CH2 or
    methylene group.
  • All alkanes have this general formula.
  • CnH2n2
  • For example ethane, C2H6 , and propane, C3H8 ,
    are the next two family members.

8
Alkanes and Cycloalkanes
  • Isomers are chemical compounds that have the same
    molecular formulas but different structures.
  • Two alkanes have the molecular formula C4H10.
  • They are a specific type of isomer called
    structural isomers.

9
Alkanes and Cycloalkanes
  • Three alkanes have the formula C5H12.
  • There are three structural isomers of pentane.

10
Alkanes and Cycloalkanes
  • Three alkanes have the formula C5H12.
  • There are three structural isomers of pentane.

11
Alkanes and Cycloalkanes
  • Three alkanes have the formula C5H12.
  • There are three structural isomers of pentane.

12
Alkanes and Cycloalkanes
  • There are five isomeric hexanes, C6H14.
  • You draw them!

13
Alkanes and Cycloalkanes
  • There are five isomeric hexanes, C6H14.

14
Alkanes and Cycloalkanes
  • There are five isomeric hexanes, C6H14.

15
Alkanes and Cycloalkanes
  • There are five isomeric hexanes, C6H14.

16
Alkanes and Cycloalkanes
  • There are five isomeric hexanes, C6H14.

17
Alkanes and Cycloalkanes
  • The number of structural isomers increases
    rapidly with increasing numbers of carbon atoms.
  • The boiling points of the alkanes increase with
    molecular weight.

18
Alkanes and Cycloalkanes
  • Cyclic saturated hydrocarbons are called
    cycloalkanes.
  • They have the general formula CnH2n.
  • Some examples are

19
Alkanes and Cycloalkanes
  • Cyclic saturated hydrocarbons are called
    cycloalkanes.
  • They have the general formula CnH2n.
  • Some examples are

20
Alkanes and Cycloalkanes
  • Cyclic saturated hydrocarbons are called
    cycloalkanes.
  • They have the general formula CnH2n.
  • Some examples are

21
Naming Saturated Hydrocarbons
  • The International Union of Pure and Applied
    Chemistry (IUPAC) names for the first 12
    "straight-chain" or "normal" alkanes are given in
    this table.

Number of carbon atoms in chain Name
1 Methane
2 Ethane
3 Propane
4 Butane
5 Pentane
6 Hexane
22
Naming Saturated Hydrocarbons
Number of carbon atoms in chain Name
7 Heptane
8 Octane
9 Nonane
10 Decane
11 Unidecane
12 Dodecane
23
Naming Saturated Hydrocarbons
  • Other organic compounds are named as derivatives
    of the alkanes.
  • Branched-chain alkanes are named by the following
    rules.
  • Choose the longest continuous chain of carbon
    atoms which gives the basic name or stem.

24
Naming Saturated Hydrocarbons
  • Number each carbon atom in the basic chain,
    starting at the end that gives the lowest number
    to the first group attached to the main chain
    (substituent).
  • For each substituent on the chain, we indicate
    the position in the chain (by an Arabic numeric
    prefix) and the kind of substituent (by its
    name).
  • The position of a substituent on the chain is
    indicated by the lowest number possible.
  • The number precedes the name of the substituent.

25
Naming Saturated Hydrocarbons
  • When there are two or more substituents of a
    given kind, use prefixes to indicate the number
    of substituents.
  • di 2, tri 3, tetra 4, penta 5, hexa 6,
    hepta 7, octa 8, and so on.
  • The combined substituent numbers and names serve
    as a prefix for the basic hydrocarbon name.
  • Separate numbers from numbers by commas and
    numbers from words by hyphens.
  • Words are "run together".

26
Naming Saturated Hydrocarbons
  • Alkyl groups (represented by the symbol R) are
    common substituents.
  • Alkyl groups are fragments of alkanes in which
    one H atom has been removed for the connection to
    the main chain.
  • Alkyl groups have the general formula CnH2n1.
  • In alkyl groups the -ane suffix in the name of
    the parent alkane is replaced by -yl.
  • A one carbon group is named methyl.
  • A two carbon group is named ethyl.
  • A three carbon group is named propyl.

27
Unsaturated Hydrocarbons
  • The three classes of unsaturated hydrocarbons
    are
  • alkenes and cycloalkenes, CnH2n
  • alkynes and cycloalkynes, CnH2n-2
  • aromatic hydrocarbons

28
Alkenes
  • The simplest alkenes contain one CC bond per
    molecule.
  • The general formula for simple alkenes is CnH2n.
  • The first two alkenes are
  • ethene, C2H4

29
Alkenes
  • The simplest alkenes contain one CC bond per
    molecule.
  • The general formula for simple alkenes is CnH2n.
  • The first two alkenes are
  • and propene, C3H6

30
Alkenes
  • Each doubly bonded C atom is sp2 hybridized.
  • The sp2 hybrid consists of
  • two s bonds (single bonds) and
  • one s and one p bond (double bond)

31
Alkenes
  • The systematic naming system for alkenes uses the
    same stems as alkanes.
  • In the IUPAC system, the -ane suffix for alkanes
    is changed to -ene.
  • Common names for the alkenes have the same stem
    but use the suffix -ylene is used.
  • In chains of four or more C atoms, a numerical
    prefix shows the position of the lowest-numbered
    doubly bonded C atom.
  • Always choose the longest chain that contains the
    CC bond.

32
Alkenes
  • Polyenes contain two or more double bonds per
    molecule.
  • Indicate the number of double bonds with
    suffixes
  • -adiene for two double bonds.
  • -atriene for three double bonds, etc.
  • The positions of the substituents are indicated
    as for alkanes.
  • The position of the CC bond(s) is/are given the
    lowest number(s) possible.

33
Alkenes
34
Alkenes
35
Alkenes
36
Cycloalkenes
  • Cycloalkenes have the general formula CnH2n-2.
  • Examples are
  • cyclopentene

37
Cycloalkenes
  • cyclohexene

38
Cycloalkenes
  • cycloheptene

39
Alkynes
  • Alkynes contain C?C bonds.
  • The simplest alkyne is C2H2, ethyne, or
    acetylene.
  • Alkynes with only one C ? C bond have the formula
    CnH2n-2.
  • Each carbon atom in a C ? C bond is sp
    hybridized.
  • Each sp hybrid contains two ? bonds and two ?
    bonds.
  • The carbon atom will have one single bond and one
    triple bond.

40
Alkynes
  • Alkynes are named like the alkenes except that
    the suffix -yne is used with the characteristic
    stem
  • The alkyne stem is derived from the name of the
    alkane with the same number of carbon atoms.

41
Alkynes
  • Acetylene is an important industrial chemical.
  • It is prepared by the reaction of calcium carbide
    with water.

42
Alkynes
  • Acetylene burns in a highly exothermic reaction
  • The combustion produces temperatures of about
    3000C.
  • Acetylene is used in cutting torches for welding.
  • Alkynes are very reactive
  • The two p bonds are sights of special reactivity.
  • Addition reactions, such as hydrogenation, are
    common.

43
Hydrocarbons A Summary
Carbon Atom Hybridization C uses C forms Example
sp3 tetrahedral 4 sp3 hybrids 4 ? bonds CH4
sp2 trigonal planar 3 sp2 hybrids 1p orbital 3 ? bonds 1 ? bond C2H4
sp linear 2 sp hybrids 2 p orbitals 2 ? bonds 2 ? bonds C2H2
44
Aromatic Hydrocarbons
  • Historically, aromatic was used to describe
    pleasant smelling substances.
  • Now it refers to benzene, C6H6, and derivatives
    of benzene.
  • Other compounds that have similar chemical
    properties to benzene are also called aromatic.

45
Benzene
  • The structure of benzene, C6H6, is

46
Other Aromatic Hydrocarbons
  • Coal tar is the common source of benzene and many
    other aromatic compounds.
  • Some aromatic hydrocarbons that contain fused
    rings are
  • napthalene

47
Other Aromatic Hydrocarbons
  • phenanthrene

48
Other Aromatic Hydrocarbons
  • Many aromatic hydrocarbons contain alkyl groups
    attached to benzene rings (as well as to other
    aromatic rings).
  • The positions of the substituents on benzene
    rings are indicated by the prefixes
  • ortho- (o-) for substituents on adjacent C atoms
  • meta- (m-) for substituents on C atoms 1 and 3
  • para- (p-) for substituents on C atoms 1 and 4

49
Other Aromatic Hydrocarbons
50
Functional Groups
  • Functional groups are groups of atoms that
    represent potential reaction sites.
  • Compounds that contain a given functional group
    usually undergo similar reactions.
  • Functional groups influence physical properties
    as well.

51
Organic Halides
  • A halogen atom may replace almost any hydrogen
    atom in a hydrocarbon.
  • The functional group is the halide (-X) group.
  • Examples include
  • chloroform, CHCl3

52
Organic Halides
  • 1,2-dichloroethane, ClCH2CH2Cl

53
Organic Halides
  • para-dichlorobenzene

54
Alcohols and Phenols
  • The functional group in alcohols and phenols is
    the hydroxyl (-OH) group.
  • Alcohols and phenols can be considered
    derivatives of hydrocarbons in which one or more
    H atoms have been replaced by -OH groups.
  • Phenols are derivatives of benzene in which one H
    has been replaced by replaced by -OH group.

55
Alcohols and Phenols
  • Ethyl alcohol (ethanol), C2H5OH, is the most
    familiar alcohol.

56
Alcohols and Phenols
  • Phenol, C6H5OH, is the most familiar phenol.

57
Alcohols and Phenols
  • Alcohols are considered neutral compounds because
    they are only very slightly acidic.
  • Alcohols can behave as acids but only in the
    presence of very strong bases.
  • Phenols are weakly acidic.
  • Ka ? 1.0 x 10-10 for phenol
  • Although phenols are very weakly acidic, they are
    also very corrosive.

58
Alcohols and Phenols
  • Alcohols can be classified into three classes
  • Primary (1) alcohols like ethanol have the -OH
    group attached to a C atom that has one bond to
    another C atom.

59
Alcohols and Phenols
  • Secondary(2) alcohols have the OH group
    attached to a C atom that has bonds to 2 other C
    atoms.
  • For example,2-propanol

60
Alcohols and Phenols
  • Tertiary (3) alcohols have the OH group
    attached to a C atom that is bonded to 3 other C
    atoms.
  • For example, 2-methyl-2-propanol

61
Alcohols and Phenols
  • The stem for the parent hydrocarbon plus an -ol
    suffix is the systematic name for an alcohol.
  • A numeric prefix indicates the position of the
    -OH group in alcohols with three or more C atoms.
  • Common names are the name of the appropriate
    alkyl group plus alcohol.

62
Alcohols and Phenols
  • Alcohols are named using the stem for the parent
    hydrocarbon plus an -ol suffix in the systematic
    nomenclature.
  • A numeric prefix indicates the position of the
    -OH group in alcohols with three or more C atoms.
  • Common alcohol names are the name of the
    appropriate alkyl group plus the word alcohol.

63
Alcohols and Phenols
  • There are several isomeric monohydric acyclic
    (contains no rings) alcohols that contain more
    than three C atoms.
  • There are four isomeric four-carbon alcohols.

64
Alcohols and Phenols
65
Alcohols and Phenols
  • There are eight isomeric five-carbon alcohols.
  • You do it!

66
Alcohols and Phenols
  • Polyhydric alcohols contain more than one -OH
    group per molecule.

67
Alcohols and Phenols
  • Phenols are usually called by their common
    (trivial) names.

68
Alcohols and Phenols
  • Phenols are usually called by their common
    (trivial) names.

69
Alcohols and Phenols
  • Phenols are usually called by their common
    (trivial) names.

70
Alcohols and Phenols
  • Phenols are usually called by their common
    (trivial) names.

71
Alcohols and Phenols
  • Because the -OH group is quite polar, the
    properties of alcohols depend upon the number of
    -OH groups per molecule and the size of the
    organic group.
  • The boiling points of monohydric alcohols
    increase with increasing molecular weight.
  • The solubility of monohydric alcohols in water
    decrease with increasing molecular weight.
  • Polyhydric alcohols are more soluble in water
    because of the two or more polar groups (-OH).

72
Ethers
  • Ethers may be thought of as derivatives of water
    in which both H atoms have been replaced by alkyl
    or aryl groups.

73
Ethers
  • Ethers may be thought of as derivatives of water
    in which both H atoms have been replaced by alkyl
    or aryl groups.

74
Ethers
  • Ethers may be thought of as derivatives of water
    in which both H atoms have been replaced by alkyl
    or aryl groups.

75
Ethers
  • Ethers are not very polar and not very reactive.
  • They are excellent solvents.
  • Common names are used for most ethers.

76
Aldehydes and Ketones
  • The functional group in aldehydes and ketones is
    the carbonyl group.

77
Aldehydes and Ketones
  • Except for formaldehyde, aldehydes have one H
    atom and one organic group bonded to a carbonyl
    group.

78
Aldehydes and Ketones
  • Ketones have two organic groups bonded to a
    carbonyl group.

79
Aldehydes and Ketones
  • Common names for aldehydes are derived from the
    name of the acid with the same number of C atoms.
  • IUPAC names are derived from the parent
    hydrocarbon name by replacing -e with -al.

80
Aldehydes and Ketones
  • Common names for aldehydes are derived from the
    name of the acid with the same number of C atoms.
  • IUPAC names are derived from the parent
    hydrocarbon name by replacing -e with -al.

81
Aldehydes and Ketones
  • Common names for aldehydes are derived from the
    name of the acid with the same number of C atoms.
  • IUPAC names are derived from the parent
    hydrocarbon name by replacing -e with -al.

82
Aldehydes and Ketones
  • The IUPAC name for a ketone is the characteristic
    stem for the parent hydrocarbon plus the suffix
    -one.
  • A numeric prefix indicates the position of the
    carbonyl group in a chain or on a ring.

83
Aldehydes and Ketones
  • The IUPAC name for a ketone is the characteristic
    stem for the parent hydrocarbon plus the suffix
    -one.
  • A numeric prefix indicates the position of the
    carbonyl group in a chain or on a ring.

84
Aldehydes and Ketones
  • The IUPAC name for a ketone is the characteristic
    stem for the parent hydrocarbon plus the suffix
    -one.
  • A numeric prefix indicates the position of the
    carbonyl group in a chain or on a ring.

85
Aldehydes and Ketones
  • Many aldehydes and ketones occur in nature.

86
Amines
  • Amines are derivatives of ammonia in which one or
    more H atoms have been replaced by organic groups
    (aliphatic or aromatic or a mixture of both).
  • There are three classes of amines.

87
Amines
  • Amines are derivatives of ammonia in which one or
    more H atoms have been replaced by organic groups
    (aliphatic or aromatic or a mixture of both).
  • There are three classes of amines.

88
Amines
  • Amines are derivatives of ammonia in which one or
    more H atoms have been replaced by organic groups
    (aliphatic or aromatic or a mixture of both).
  • There are three classes of amines.

89
Amines
  • Amines are derivatives of ammonia in which one or
    more H atoms have been replaced by organic groups
    (aliphatic or aromatic or a mixture of both).
  • There are three classes of amines.

90
Amines
  • Aniline is the simplest aromatic amine. It is
    much less basic than NH3.
  • Aniline is a very important industrial chemical.

91
Amines
  • Heterocylic amines have one or more N atoms in a
    ring structure.
  • Many are important in living systems.

92
Amines
  • Heterocylic amines have one or more N atoms in a
    ring structure.
  • Many are important in living systems.

93
Amines
  • Heterocylic amines have one or more N atoms in a
    ring structure.
  • Many are important in living systems.

94
Carboxylic Acids
  • Carboxylic acids contain the carboxyl functional
    group.
  • The general formula for carboxylic acids is
  • R represents an alkyl or an aryl group

95
Carboxylic Acids
  • IUPAC names for a carboxylic acid are derived
    from the name of the parent hydrocarbon.
  • The final -e is dropped from the name of the
    parent hydrocarbon
  • The suffix -oic is added followed by the word
    acid.
  • Many organic acids are called by their common
    (trivial) names which are derived from Greek or
    Latin.

96
Carboxylic Acids
97
Carboxylic Acids
  • Positions of substituents on carboxylic acid
    chains are indicated by numeric prefixes as in
    other compounds
  • Begin the counting scheme from the carboxyl group
    carbon atom.
  • They are also often indicated by lower case Greek
    letters.
  • ? 1st C atom
  • ? 2nd C atom
  • ? 3rd C atom, etc.

98
Carboxylic Acids
99
Carboxylic Acids
100
Carboxylic Acids
101
Carboxylic Acids
  • Dicarboxylic acids contain two carboxyl groups
    per molecule.

102
Nomenclature of Carboxylic Acids
  • Dicarboxylic acids contain two carboxyl groups
    per molecule.

103
Nomenclature of Carboxylic Acids
  • Dicarboxylic acids contain two carboxyl groups
    per molecule.

104
Carboxylic Acids
  • Aromatic acids are usually called by their common
    names.
  • Sometimes, they are named as derivatives of
    benzoic acid which is considered to be the
    "parent" aromatic acid.

105
Carboxylic Acids
106
Carboxylic Acids
107
Carboxylic Acids
  • Acid strengths of simple carboxylic acids vary
    little with chain length.
  • However, substituents on a carbon atom in the
    chain can cause large variations in acid
    strengths .

108
Carboxylic Acids
109
Carboxylic Acids
110
Carboxylic Acids
  • The -OH group in the carboxyl group of carboxylic
    acids, is displaced in many of their reactions.
  • The non -OH portion of a carboxylic acid is
    called an acyl group.

111
Some Derivatives of Carboxylic Acids
  • Four important classes of compounds contain acyl
    groups
  • They are all considered to be derivatives of
    carboxylic acids.
  • In these structures R's may represent either
    alkyl or aryl groups.

112
Some Derivatives of Carboxylic Acids
113
Some Derivatives of Carboxylic Acids
114
Some Derivatives of Carboxylic Acids
  • Acid anhydrides are related to their parent acids
    as follows
  • The word anhydride means without water.

115
Some Derivatives of Carboxylic Acids
  • Acyl halides are much more reactive, and more
    volatile, than their parent acids.
  • They react with water to form their parent acids
    and a hydrohalic acid.

116
Some Derivatives of Carboxylic Acids
  • Acyl halides are prepared by reacting their
    parent acids with PCl3, PCl5, or SOCl2.
  • The more volatile acid halide is then distilled
    out of the reaction mixture.

117
Some Derivatives of Carboxylic Acids
  • Esters are prepared by heating a carboxylic acid
    with an alcohol in the presence of a small amount
    of an inorganic acid.
  • The reaction mixture will contain some ester and
    water, as well as unreacted acid and alcohol.

118
Some Derivatives of Carboxylic Acids
  • Esters are usually called by their common names.
  • Many simple esters occur naturally and have
    pleasant odors.
  • Esters are frequently used in fragrances and as
    artificial flavors.

119
Some Derivatives of Carboxylic Acids
  • Fats are solid esters of glycerol and (mostly)
    saturated acids at room temperature.
  • Oils are liquid esters of glycerol and primarily
    unsaturated acids at room temperature.
  • The "acid" parts of fats and oils usually contain
    even numbers of C atoms in naturally occurring
    fats and oils.
  • 16 and 18 carbon chains are the most commonly
    found chain sizes in nature.

120
Some Derivatives of Carboxylic Acids
  • Some acids that are found (as their esters) in
    fats and oils include

121
Some Derivatives of Carboxylic Acids
  • Stearic acid is often found in beef fat.

122
Some Derivatives of Carboxylic Acids
  • Triglycerides are the triesters of glycerol.
  • The common name for triglycerides is tri (acid
    stem) plus an -in suffix.
  • For example, tripalmitin.

123
Some Derivatives of Carboxylic Acids
  • Waxes are esters of long chain fatty acids and
    alcohols other than glycerol.
  • Commonly, waxes are derived from monohydric
    alcohols.
  • Beeswax and carnauba wax are esters of myricyl
    alcohol, C30H61OH.

124
Some Derivatives of Carboxylic Acids
  • Carnauba wax is often used in car waxes.

125
Some Derivatives of Carboxylic Acids
  • Dihydric alcohols (2 OHs per molecule) can
    react with dicarboxylic acids (2 COOHs per
    molecule) to form polyesters.
  • Ester linkages are formed at both ends of both
    molecules to give polymeric esters with very high
    molecular weights.

126
Some Derivatives of Carboxylic Acids
127
Some Derivatives of Carboxylic Acids
  • Amides are derivatives of organic acids and
    primary or secondary amines.
  • The functional groups of amides are

128
Some Derivatives of Carboxylic Acids
  • Amides are also named as derivatives of
    carboxylic acids.
  • The suffix -amide is substituted for -ic acid or
    -oic acid.

129
Some Derivatives of Carboxylic Acids
  • When an aryl or alkyl substituent is present on
    the N atom, the letter N and the name of the
    substituent are prefixed to the name of the
    unsubstituted amide.

130
Some Derivatives of Carboxylic Acids
  • Acetaminophen Tylenol - is an amide.

131
Summary of the Functional Groups
  • A summary of the functional groups is

132
(No Transcript)
133
Substitution Reactions
  • In a substitution reaction an atom or group of
    atoms attached to a carbon atom is replaced
    (substituted for) by another atom or group of
    atoms.
  • There is no change in the degree of saturation at
    the reactive carbon atom.
  • Halogenation reactions are an important class of
    substitution reactions.
  • Chlorine reacts with alkanes in free radical
    chain reactions (also substitution reactions).

134
Substitution Reactions
  • Free radical chain reactions
  • The halogenation of methane is one example.

135
Substitution Reactions
136
Substitution Reactions
137
Substitution Reactions
  • Free radical chain reactions
  • Many substitution reactions of alkanes produce
    more than one product.

138
Substitution Reactions
139
Substitution Reactions
140
Substitution Reactions
  • Nitration reaction of an aromatic hydrocarbon
    replaces an H atom attached to an aromatic ring
    with a nitro, -NO2, group.

141
Addition Reactions
  • An addition reaction involves an increase in the
    number of groups attached to carbon.
  • The degree of saturation of the molecule is
    increased.

142
Addition Reactions
  • Hydrogenation is a very important kind of
    addition reaction.
  • Hydrogenation is used to convert unsaturated fats
    and oils to saturated fats or oils.

143
Elimination Reactions
  • An elimination reaction involves the removal of
    groups attached to carbon.
  • The degree of unsaturation increases.

144
Elimination Reactions
  • Dehydration is an important kind of elimination
    reaction.

145
Polymerization Reactions
  • A polymer is a large molecule that consists of a
    high-molecular weight chain of small molecules.
  • The small molecules that have been joined to form
    the polymer are called monomers.
  • Synthetic polymers are a relatively new class of
    molecules.
  • The first one, bakelite, was discovered in 1909.
  • Nylon, which is still extensively used, was
    discovered in 1930s.

146
Polymerization Reactions
  • Addition polymerization is a large commercial
    process in the United States.
  • Polyethylene is the addition polymer made in the
    largest quantities in the United States.
  • Polyethylene is used to make Coke bottles,
    plastic bags, etc.

147
Polymerization Reactions
  • Addition polymerization
  • Polyethylene formation

148
Polymerization Reactions
  • Addition polymerization
  • Teflon is the material used in nonstick frying
    pans and other kitchen utensils.

149
Polymerization Reactions
  • Formation of rubber
  • Natural rubber is a polymer made of isoprene
    (2-methyl-1,3-butadiene) units that form a unique
    stereoisomeric structure.

150
Polymerization Reactions
  • Vulcanization of rubber
  • Natural rubber is a sticky, soft compound when
    heated which limited its commercial potential.
  • Charles Goodyear discovered in 1839 that heating
    rubber with sulfur removed the stickiness and
    made the substance elastic.
  • This is the basis of modern tire production.
  • Vulcanization provides disulfide cross-linking
    bonds between the isoprene units.

151
Polymerization Reactions
  • Copolymers
  • If two different monomers are mixed and the
    polymerized, copolymers are formed.
  • Styrene butadiene rubber - SBR - is an important
    copolymer used in tire production.

152
Polymerization Reactions
  • Copolymers

153
Polymerization Reactions
154
Polymerization Reactions
  • Condensation Polymers
  • Condensation polymers occur when two molecules
    react and eliminate a small molecule.
  • Molecules eliminated commonly are water and HCl.
  • Important condensation polymers include nylon,
    dacron, and kevlar.
  • Dacron is used in clothing to make it wrinkle
    free.
  • Blood does not clot in contact with dacron thus
    it is used in artificial arteries.

155
Polymerization Reactions
  • Condensation Polymers
  • Dacron formation

156
Polymerization Reactions
157
Polymerization Reactions
  • Condensation Polymers
  • Nylon was first made by Wallace Carothers in the
    1930s.
  • Nylon is widely used in a variety of commercial
    products including stockings, rope, guitar
    strings, fire-proof clothing.

158
Polymerization Reactions
  • Condensation Polymers
  • Nylon 66 formation

159
Polymerization Reactions
160
Synthesis Question
  • TNT, the explosive ingredient in dynamite, has
    the correct name of 2,4,6-trinitrotoluene. Draw
    the structure of TNT.

161
Synthesis Question
162
Group Question
  • Aerobic respiration produces carbon dioxide and
    water as its end products. Anaerobic respiration
    has different end products. What are the end
    products of anaerobic respiration? How could you
    easily detect that someone has switched from
    aerobic to anaerobic respiration?

163
End of Chapter 27
  • There are more organic compounds than any other
    type of chemical species.
About PowerShow.com