Download Chapter 2 Representative Carbon Compounds: Functional Groups

ORGANIC CHEMISTRY
Chapter 2
2.5 Functional Groups
官能团
Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY
Chapter 2
Functional groups
The structural features that make it possible to
classify compounds by reactivity are called
functional groups.
A functional group is a part of a larger molecule
and is composed of an atom or a group of atoms
that have a characteristic chemical behavior.
The Chemistry of every organic molecules,
regardless of size and complexity, is determined
by the functional groups it contains.
Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY
Chapter 2
2.5A Alkyl Group and the Symbol R
Alkyl groups (烷基) are the groups that we
identify for purposes of naming compounds.
They are groups that would be obtained by
removing a hydrogen atom from an alkane
R is used as a general symbol to represent any
alkyl group.
CH4
CH3CH3
CH3
CH3CH2
CH3CH2CH3
CH3CH2CH2
CH3CH2CH3
CH3CHCH3
or C2H5
or (CH3)2CH
Me
Et
Methyl
Ethyl
Pr
Propyl
i-Pr
Isopropyl
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Chapter 2
2.5B Phenyl and Benzyl Groups
Phenyl group (苯基)
C6H5
Ar
φ
Ph
(if ring substitutents are present)
Benzyl group (苄基)
CH2
CH2
C6H5CH2
Bn
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Chapter 2
2.6 Alkyl Halides or Haloalkanes
烷基卤或卤代烷
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Chapter 2
Alkyl halides (haloalkanes) are compounds in
which a halogen atom (F, Cl, Br, or I) replaces
a hydrogen atom of an alkane.
CH3CH3
Ethane
An alkane
CH3CH2Cl
Ethyl chloride
An alkyl halide
CH3CH2CH3
CH3CHCH3
Br
Alkyl halides are classified as being primary (伯，
一级) (1°), secondary(仲，二级) (2°), or
tertiary(叔，三级) (3°) — based on the carbon
atom to which the halogen is directly attached.
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Chapter 2
Primary carbon atom Secondary carbon atom Tertiary carbon atom
CH3 C
CH3
CH3
H
Cl
H
Primary alkyl halide
CH3 C
Cl
CH3 C
Cl
CH3
H
Secondary alkyl halide
Tertiary alkyl halide
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Chapter 2
2.7 Alcohols
醇类
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Chapter 2
The characteristic functional group of alcohols
is the hydroxyl group (–OH) attached to an sp3hybridized carbon atom.
C OH
Hydroxyl group (羟基)
Alcohols are classified into three groups:
Primary (1°) alcohols (伯醇或一级醇)
Secondary (2°) alcohols (仲醇或二级醇)
Tertiary (3°) alcohols (叔醇或三级醇)
Department of Chemistry, Xiamen University
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Chapter 2
Primary carbon atom Secondary carbon atom Tertiary carbon atom
CH3
H
CH3
CH3 C OH
CH3 C OH
H
H
Primary alcohol
CH3 C OH
CH3
Secondary alcohol
Tertiary alcohol
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Chapter 2
2.8 Ethers
醚类
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Chapter 2
An ether is a substance that has two organic residues
bonded to the same oxygen atom.
The organic residues may be alkyl, aryl, or vinylic, and
the oxygen atom can be part of either an open chain or
a ring.
R O R'
R,R' = H
R' = R, alkyl, aryl, vinyl
O
CH3CH2 O CH2CH3
Diehtyl ether
乙醚
O CH3
H 2C
CH2
O
Anisole
Ethylene oxide Tetrahydrofuran
(methyl phenyl ether)
(THF)
环氧乙烷
茴香醚
四氢呋喃
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Chapter 2
2.9 Amines
胺类
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Chapter 2
Amines may be considered as organic
derivatives of ammonia.
H
H N H
H
R N H
C6H5CH2CHCH3
H2NCH2CH2CH2CH2NH2
NH2
Ammonia
An amine
Amphentamine
安非他命
Putrescine
腐胺
Amines are classified as primary, secondary, or
tertiary amines — based on the number of
organic groups that are attached to the nitrogen
atom. H
R'
R'
R N H
R N H
R N R"
A primary amine
A secondary amine
伯胺，一级胺
仲胺，二级胺
A tertiary amine
叔胺，三级胺
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Chapter 2
2.10 Aldehydes and Ketones
醛和酮
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Aldehydes and ketones both contain the
carbonyl group (羰基) — a group in which a
carbon atom has a double bond to oxygen.
C O
The carbonyl group
Aldehydes
Ketones
O
R C H
O
R C R
O
R C R'
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Chapter 2
2.11 Carboxylic Acids, Amides,
and Esters
羧酸、酰胺和酯
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Chapter 2
2.11A Carboxylic acids
Carboxylic acids have the general formula:
O
R C OH
or
RCOOH
or
RCO2H
A carboxylic acid
The functional group is the carboxyl group (羧
基).
O
C OH
or
－COOH
or
－CO2H
The carboxyl group
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Chapter 2
2.11B Amides
Amides have the formulas RCONH2,
RCONHR’, or RCONR’R”.
O
R C NH2
CH3
O
C NH2
acetamide
乙酰胺
O
R C NHR'
O
C NHCH3
N-methylbenzamide
N-甲基苯甲酰胺
O
R C N R'
R"
O
H C N(CH3)2
N,N-dimethylformamide
(DMF)
N,N-二甲基甲酰胺
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Chapter 2
2.11C Esters
Esters have the general formula RCO2R’.
O
R C OR'
or
O
CH3 C OCH2CH3
Ethyl acetate
RCOOR' or
RCO2R'
O
C OCH3
Methyl benzoate
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Chapter 2
2.12 Nitriles
腈类
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Chapter 2
Compounds containing the –CN functional
group are called nitriles.
Acyclic nitriles are named by adding the suffix
nitrile to the name corresponding hydrocarbon.
sp3 hybridized
CH3 C N
Ethanenitrile
(acetonitrile)
C N
CH2
CH C N
Propenenitrile
(acrylonitrile)
Cyclic nitriles are named by adding the suffix
carbonitrile to the name of the ring system to
which the –CN group is attached.
C N
Benzenecarbonitrile
C N
Cyclohexanecarbonitrile
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