第二周预习思考题
1、有机化合物命名的一般步骤怎样？母体如何选择？各种基团（官能团）的英文词头或词尾的变化规律如何？
2、各种碳氢化合物的稳定性如何？芳香性与共振论是怎么回事？如何画极限共振结构式，并判断它们的能量高低？
3、化合物结构与物理性质的关系如何？
4、非共价弱作用力有哪些？
第二章碳氢化合物
Hydrocarbon
第二章重点讲解问题
1,碳氢化合物的命名（以烷烃和环烷烃为例）
2,碳氢化合物的稳定性
3,共轭烯烃、芳香性与共振论和分子轨道理论
4,碳氢化合物的物理性质与分子间作用力关系
2.1 碳氢化合物的分类与命名
2.1.1 Classification of hydrocarbon
Alkanes and Cycloalkanes
Alkenes (cis and trans) (Z and E)
Conjugated dienes
Aromatic hydrocarbons
Alkynes
2.1 碳氢化合物的分类与命名
2.1.2 Representing Molecules
Molecular formula CH4 H
a Stick figure H C H
a Lewis dot structure H
a Sawhorse representation
2.1 碳氢化合物的分类与命名
2.1.3 通式与不饱和度（环的数目）
Saturated Hydrocarbons,CnH2n+2
For a formula,CnHm
Degree of unsaturated= (2n+2-m)/2
If it is a cycloalkane,the degree of
unsaturated equals to the number of ring
2.1.4 Nomenclature
Common Name and Systematic Name
CH4 CH3CH3 CH3CH2CH3
Methane Ethane Propane
CH3CH2CH2CH3 CH3CHCH3
CH3
C,N,n-butane isobutane
S,N,Butane 2-methylpropane
2.1.4 Nomenclature
CH3CH2CH2CH2CH3 Pentane
CH3CHCH2CH3 isopentane,2-methylbutane
CH3
CH3
CH3CCH3 neopentane,2,2-dimethylpropane
CH3
2.1.4 Nomenclature
CH3CH2CH2CH2CH2CH3 hexane
CH3CHCH2CH2CH3 isohexane,2-methylpentane
CH3
CH3
CH3CCH2 CH3 neohexane,2,2-dimethylbutane
CH3
2.1.4 Nomenclature
CH3CH2CHCH2CH3 none 3-methylpentane
CH3
CH3CH-CHCH3 none 2,3-dimethylbutane
CH3 CH3
Alkyl Group R- (replacing,ane” with,yl”)
primary,secondary,tertiary,quaternary C,but
only primary,secondary,tertiary H
( see our text )
2.1.4 Nomenclature (IUPAC Rules)
Systematic Name (IUPAC Rules)
(IUPAC,International Union of Pure and Applied Chemistry)
1,Determine the number of carbon in the
longest continuous carbon chain----This chain is
called the parent hydrocarbon.
1 2 3 4 5 6 7 8
CH3CH2CHCH2CH2CH2CH2CH3 3-methyl Octane
CH3
CH3CHCH2CH2CH3 4-methyl Octane
CH2CH2CH2CH3
2.1.4 Nomenclature (IUPAC Rules)
2,Number the chain so that the
substituent gets the lowest possible
number,
CH3CH2CHCH2CHCH2CH2CH3 5-ethyl-3-methyloctane
CH3 CH2CH3 not 4-ethyl-6-methyloctane
because 3 < 4
CH2CH3
CH3CHCHCH2CH2CHCH3 3-ethyl-2,6-dimethylheptane
CH3 CH3 not 5-ethyl-2,6-dimethylheptane
because 3 < 5
2.1.4 Nomenclature (IUPAC Rules)
3,Cite the name of the alkyl substituent
before the parent hydrocarbon,---- A
number and a word are separated by a
hyphen; numbers are separated by a
comma,di,tri,tetra is used to express the
number of the same substituents
CH3CH2CHCH2CHCH3 2,4-dimethylhexane
CH3 CH3
2.1.4 Nomenclature (IUPAC Rules)
And list substituents in alphabetical order,
----,di,tri,tetra,sec,and tert” are ignored
in alphabetizing.,iso,neo,and cyclo” are
not ignored in alphabetizing.
3HC2HC CH3
CH3CH2CCH2CH2CHCHCH2CH2CH3 3,3,6-triethyl-7-methyldecane
3HC2HC CH2CH3
CH3
CH3CH2CH2CHCH2CH2CHCH3 5-isopropyl-2-methyloctane
CH(CH3)2
2.1.4 Nomenclature (IUPAC Rules)
4,If the same substituent number are
obtained in both directions,the first cited
group received the lower number.
CH3 3-ethyl-5-methylheptane
CH3CH2CHCH2CHCH2CH3 not
CH2CH3 5-ethyl-3-methylheptane
Cl 2-bromo-3-chlorobutane
CH3CHCHCH3 not
Br 3-bromo-2-chlorobutane
2.1.4 Nomenclature (IUPAC Rules)
5,If a compound had two or more chains
of the same length,the parent
hydrocarbon is the chain with the greatest
number of substituents.
CH3CH2CHCH2CH2CH3 CH3CH2CHCH2CH2CH3
CHCH3 CHCH3
CH3 CH3
3-ethyl-2-methylhexane not 3-isopropylhexane
(two substituents) (one substituent)
2.1.4 Nomenclature (IUPAC Rules)
6,If there are some complex substituents,
we can use the similar method to name
the substituents,
CH3CH2CHCH2CH2CH3 CH3CH2CH2CHCH2CH2CH3
1 2 1 2 3
CHCH3 CH2CHCH3
CH3 CH3
3-isopropylhexane or 4-isobutylheptane or
3-(1-methylethyl)hexane 4-(2-methylpropyl)heptane
2.1.4 Nomenclature (IUPAC Rules)
当一个饱和支链无环烃具有相同长度的链可作为主链时，则选择的顺序为：
1）具有侧链数目最多的链
4-propyl-2,3,5-
trimethylheptane
not
3-methyl-4-(1,2-
dimethylpropyl)heptane
C H 3 C H 2 C H C H C H
C H 3 C H
2
C H 3
C H C H 3
C H 3
C H 2 C H 3
2.1.4 Nomenclature (IUPAC Rules)
2）侧链具有最低位次的链
2,5-dimethyl-4-(1-
methylpropayl)heptane (not 3,4,5)
C H C H 2 - C H C H 3
C H C H 3
C H 3 C H 2 C H
C H 2 C H 3
C H 3 C H
3
2.1.4 Nomenclature (IUPAC Rules)
3）在较短的侧链中，具有碳原子数目最多的链
（各侧链数分别为 111288和 111189）
3-ethyl- 5,9,11-trimethyl-7,7-di(2,4-
dimethylhexyl)tridecane
C
CH 2 CHCH 2 CHCH 2 CH 3
CH 2 CHCH 2 CHCH 2 CH 3
CH 3 CH 2 CHCH 2 CHCH 2
CH 3 CH 2 CHCH 2 CHCH 2
CH 3 CH
3
CH 3 CH 3 CH 3 CH 2 CH 3
CH 3 CH 3
课堂练习：
请给出上述结构的中英文 IUPAC命名
1,4-(1-ethylpropyl)-
2,5,6,6-tetramethyloctane
2,1-ethyl-2-mehylcyclopentane
C H 3 C H 2 C - C H C H C H 2 C H C H 3
C H 3 C H C H
2 C H 3
C H 3C H 3
C H 2 C H 3
C H 3
C H 2 C H 3
C H 3
1,2,
2.1.4 Nomenclature (IUPAC Rules)
7,For cycloalkane,(skeletal structure)
1) In the case of a cycloalkane with an
attached alkyl substituent,the ring is the
parent hydrcarbon unless the substituent
has more carbons than the ring,
A,Isopropylcyclohexane
B,1-cyclobutylpentane
CH 2 ( C H 3 ) 2 CH
2 CH 2 CH 2 CH 2 CH 3A,B.
2.1.4 Nomenclature (IUPAC Rules)
2) If the ring has two different substituents,they
are cited in alphabetical order and the number 1
position is given to the first cited substituent.
A,1-ethyl-3-methylcyclopentane
B,1,3-dimethylcyclohexane
CH 2 CH 3H 3 C CH 3H 3 CA,B.
2.1.4 Nomenclature (IUPAC Rules)
3) If there are more than two substituents on the
ring,give the number 1 position to the
substituent that result in a second substituent
getting as low a number as possible.
A,1,1,2-trimethylcyclopentane
(not 1,2,2; not 1,1,5)
B,4-ethyl-2-methyl-1-propylcyclohexane
not 1,3,4,(2<3); not 5,1,2,(4<5)
CH 3
CH 3
CH 3
H 3 CH 2 CH 2 C
H 3 C CH 2 CH 3A,B,
以下内容请自学：
Nomenclature of Alkenes (cis and trans)
(Z and E)
Alkynes
Conjugated dienes
Aromatic hydrocarbons
2.2 碳氢化合物的稳定性
2.2.1 Saturated hydrocarbons ---- Alkanes
relatively stable
2.2.2 Cycloalkanes ---- Ring Strain
Instability of three- and four-member rings
---- due to angle strain
1 0 9,5 0
60 0 90
0
2.2 碳氢化合物的稳定性
2.2.3 Alkenes ---- Pi Bonding
The functional group is the center of
reactivity of a molecule,Carbon-carbon
double bond (C=C) is the functional group
of alkenes,
Strength of Bond,C-C 347.3 kJ/mole
C=C 610.9 kJ.mole
a Pi Bond is weaker than a Sigma Bond
2.2 碳氢化合物的稳定性
2.2.4 Alkynes ---- Pi Bond
Strength of Bond,C-C 347.3 kJ/mole
C=C 610.9 kJ.mole
C=C 836.8 kJ/mole
Pi Bond in C=C,263.6 kJ/mole
Pi Bond in C=C,244.8 kJ/mole
an alkyne is less reactive than an alkene
Why?（ Please think it out by yourself）
2.2 碳氢化合物的稳定性
Class of dienes,conjugated
isolated
cumulated
Heat of Formation:
n C + n H2 Cn H 2n + h eat ( Hf 0 )
Gr ap h i t e Gas
2.2 碳氢化合物的稳定性
The difference between the heats reflects the
difference in stability between the
nonconjugated and conjugated dienes
2.2 碳氢化合物的稳定性
2.2.5 Aromatic hydrocarbons
Benzene,with relatively few hydrogens
comparing with aliphatic compound,is a
particularly stable compound because it has an
unusually large resonance energy 151kJ/mole)3 H 2
H
0
- 4 9,3 k c a l / m o l e
H
0
- 2 8,4 k c a l / m o l e
H 2
Questions:
Why is a conjugated diene more stable
than an isolated diene?
Why is benzene a particularly stable
compound?
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Conjugated Dienes
1,Single bond between C2-C3 formed by
sp2-sp2 overlap,the length of the bond is
shorter,therefore the bond is stronger.
CH3--CH3 Csp3-Csp3 154pm
CH2=CH--CH3 Csp2-Csp3 150pm
CH2=CH--CH=CH2 Csp2-Csp2 146pm
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
2,Structure of Conjugated Dienes:
3,The conjugated diene had delocalized
electrons,We can draw the resonance structure:
resonance hybrid:
H 2 C CH CH CH 2
CH 2 - - C H = C H - - C H 2 C H2 = C H - - C H = C H 2 C H2 - - C H = C H - - C H 2+ +- -
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
分子轨道理论阐述 1,3-丁二烯的结构
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Structure of Benzene
1,All the carbon are
sp2 hybridized
2,The p orbital on each carbon can
overlap with two adjacent p orbitals.
3,p-electrons in benzene are delocalized,
we call such compound to have
resonance.
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
电子离域与共振
上述结构较好地表示了电子的离域，但是却无法告诉我们该结构中含有多少双键。
因此化学家常用共振结构来表示。
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Some basic concepts
1,A compound with delocalized electrons is said
to have resonance
2,The approximate structure using localized
electrons is called a resonance contributor,a
resonance structure,or a contributing
resonance structure
3,The catual structure,drawn using delocalized
eletrons,is called a resonance hybrid.
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Rules for Drawing Resonance Contributors
1,Only electrons move,The nuclei of the atoms
never move
2,The only electrons that can move are π
electrons and nonbonding electrons
3,The total number of electrons in the molecule
does not change,neither do the numbers of
paired and unpaired electrons
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
4,The electrons can be moved in one of the
following ways
1) Move π electrons toward a positive charge or
toward a π bond
H 3 C H C C
H
C H C H 3CH 3 CH = CH - - - CH CH 3 CH 3 CH - - - CH = CH CH 3
+ +
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
2) Move a nonbonding pair of electrons toward a
π bond
CH 3 C H = C H - - - O - - - C H 3 C H 3 C H - - - C H = O - - - C H 3
H 3 C H C C
H
O CH 3
r e s o n a n c e c o n t r i b u t o r s
r e s o n a n c e h y b r i d
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
3,Move a single nonbonding electron toward a
π bond
H 3 C C
H
C
H
CH 2 H 3 C C
H
C
H
CH 2
H 3 C C
H
C
H
CH 2
r e s o n a n c e c o n t r i b u t o r s
r e s o n a n c e h y b r i d
课堂练习：
请给出上述结构的中英文 IUPAC命名
1,4-(1-ethylpropyl)-
2,5,6,6-tetramethyloctane
not 3,3,4,7-tetramethyl-5-(1-ethylpropyl)-
2,1-ethyl-2-mehylcyclopentane
C H 3 C H 2 C - C H C H C H 2 C H C H 3
C H 3 C H C H
2 C H 3
C H 3C H 3
C H 2 C H 3
C H 3
C H 2 C H 3
C H 3
1,2,
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
2,Structure of Conjugated Dienes:
3,The conjugated diene had delocalized
electrons,We can draw the resonance structure:
resonance hybrid:
H 2 C CH CH CH 2
CH 2 - - C H = C H - - C H 2 C H2 = C H - - C H = C H 2 C H2 - - C H = C H - - C H 2+ +- -
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Aromaticity and Huckel’s Rule
Benzene ------ perticularly stable
because of the resonance energy
But cyclobutadiene and
cyclooctatetraene containscyclic two
or four Pi-bond,they are not stable,
Aromaticity and Huchel’s Rule
In 1938,a German chemist Erich
Huckel recognized the difference
between them and generalized this
obeservation into Huckel’s Rule
------- any plannar,cyclic,conjugated
system containing (4n+2) Pi electrons
(where n is an integer) experiences
unusual aromatic stabilization
Aromaticity and Huchel’s Rule
Molecular Orbital theory
------- in benzene6
Aromaticity and Huchel’s Rule
Molecular Orbital theory
------- in cyclooctatetraene
8
Aromaticity and Huchel’s Rule
Other member rings
0
-1
-2
1
2
0,6 1 8
- 1,6 1 8
1,2 4 7
-,4 4 5
- 1,8 0 2
1,4 1 4
- 1,4 1 4
Aromaticity and Huchel’s Rule
Other Aromatic molecules:
1,6-桥连 [10]-轮烯
[14]-轮烯,[18]-轮烯,[22]-轮烯
（请思考为什么 [10]-轮烯没有芳香性）
+
++ - - - ++
2.4 碳氢化合物的物理性质
2.4.1,Boiling Points
Depend on the strength of the attractive
forces between the individual molecules
In Alkanes,C-C C-H nonpolar bonds
van der Waals forces ---- induced dipole-
induced-dipole interactions
C=O,C-O polar bonds
dipole-dipole interaction
2.4 碳氢化合物的物理性质
Van der Waals forces are the weakest of
all the intermolecular attraction
It depends on the area of contact between
the molecules
The boiling points of alkanes increase as
their size increase
And a branched compound has a
relatively lower boiling point
2.4 碳氢化合物的物理性质
2.4.2,Melting Points
Packing influences the melting point of a
compound
Packing is a property that determines how well
the individual molecules in a sold fit together in
the crystal lattice
The tighter the fit,the more energy required to
break the lattice and melt the compound,
2.4 碳氢化合物的物理性质
2.4.3 Solubility
General Rule,Like dissolves like
第二章重点讲解问题
1,碳氢化合物的命名（以烷烃和环烷烃为例）
2,碳氢化合物的稳定性
3,共轭烯烃、芳香性与共振论和分子轨道理论
4,碳氢化合物的物理性质与分子间作用力关系第三章 含官能团化合物命名、结构和物理性质第三章重点讲授内容
一、含官能团化合物的命名
二、官能团化合物的结构和物理性质
三、含氧、含氮杂环化合物简介
四、金属有机化合物简介一、含官能团化合物的命名
1,Alkyl Halides
In the IUPAC system,alkyl halides are
named as substituted alkanes,alkenes
or alkynes,
The substituent prefix names for the
halogens replaces the,ine”ending in
the name of the element with,o”
------ floro,chloro,bromo,iodo
一、含官能团化合物的命名
A,2-bromo-5-methylheptane
B,1-chloro-6,6-dimethyl-3-heptene
CH 3 CH 2 C H C H 2 CH 2 C H C H 3
CH 3
Br
A,B,CH 3 CCH 2 C H =C H C H 2 CH 2 Cl
CH 3
CH 3
一、含官能团化合物的命名
C,1,6-dichloro(-1-)cyclohaxene
D,6-bromo-3-chloro-4-methyl (-1-)
cyclohexene
E,(Z)-2-bromo-4-ethyl-7-methyl-4-
octene
Cl
Cl Cl
CH 3Br
C,D,CH 3 CHCH 2
CH 3
Br
C C
CH 2 CHCH 3
CH 2 CH 3H
E.
一、含官能团化合物的命名
2,Ethers
The IUPAC system names an ether as
an alkane,alkene or alkyne that has an
RO subsituent,
The substituents are named by
replacing the,yl” ending in the name
of the alkyl subtituent with,oxy”
一、含官能团化合物的命名
A,1-ethoxy-3-methyl-2-pentene
B,1,4-diisopropoxybutane
A,CH 3 CH 3 C= CH C H 2 O CH 2 CH 3
CH 3 CH O C H 2 CH 2 CH 2 CH 2 O CH C H 3
CH 3 CH 3
CH 3
B.
一、含官能团化合物的命名
3,The following rules are used when
naming a compound that has a
functional group suffix ( Alcohols,
aldehydes,ketones,carboxylic acid
and their derivatives,amines)
一、含官能团化合物的命名
1) The parent hydrocarbon is the
longest continuous chain containing
the functional group,and is numbered
in the direction that given the
functional group suffix the lowest
possible number.
一、含官能团化合物的命名
A,2-ethyl-1-pentanol or
2-ethylpentan-1-ol
B,2-propoxy-1-ethanol or
2-propoxyethan-1-ol
CH 3 CH 2 CH 2 CHCH 2 OH
CH 2 CH 3
A.
B,CH
3 CH 2 CH 2 O C H 2 CH 2 OH
一、含官能团化合物的命名
2) If there is a functional group suffix
and a substituent,the functional group
suffix gets the lowest number,
4-methyl-1-pentanol
H O C H 2 CH 2 CH 2 CH CH 3
CH 3
一、含官能团化合物的命名
3) If the same number for the functional
group suffix is obtained in both
directions,the chain is numbered in the
direction that gives a substituent the
lowest possible number.
2-methyl-3-pentanol
not
4-methyl-3-pentanolCH 3 C H C H C H 2 CH 3
CH 3
HO
一、含官能团化合物的命名
4) If there is more than one substituent,
the substituents are cited in
alphabetical order.
6-bromo-3-ethyl-2-hexen-1-ol
H O C H 2 C H = C C H 2 CH 2 CH 2 Br
CH 2 CH 3
一、含官能团化合物的命名
Remember that the name of a
subsitituent is stated before the name
of the parent hydrocarbon,and the
functioal froup suffix is stated after the
name of the parent hydrocarbon.
一、含官能团化合物的命名
A,5-hydroxypentanal
B,4-penten-2-one (allylmethyl ketone)
C,4-methyl-2-oxo-3-hexanoic acid
H O C H 2 CH 2 CH 2 CH 2 C H OA,
B,CH
3 C C H 2 C H = C H 2
O
C,CH 3 CH 2 C H C H 2 C C O O H
CH 3 O
一、含官能团化合物的命名
A,Benzenecarbaldehyde (benzaldehyde)
B,Cyclohexylcarboxylic acid
C,3-phenylpropanoic acid
D,2-bromo-4-methylcyclohexanol
C O O H
CH 2 CH 2 C O O H
C H O B.
OH
C,Br
H 3 C
A.
D.
一、含官能团化合物的命名
A,1-butanamine or butan-1-amine
B,N-ethyl-3-hexanamine or
N-ethylhexan-3-amine
C,N-ethyl-N-methyl-1-propanamine
or N-ethyl-N-methylpropan-1-amine
CH 3 CH 2 CH 2 CH 2 NH 2 CH 3 CH 2 CH CH 2 CH 2 CH 3
N H CH 2 CH 3CH
3 CH 2 CH 2 N CH 2 CH 3
CH 3
A,B.
C.
一、含官能团化合物的命名
D,3-ethyl-N-methyl1-butanamine
E,N-ethyl-5-methyl-3-hexanamine
F,2-ethyl-N-propylcyclohexanamine
CH 3 C H C H 2 CH 2 N H C H 3
Cl
CH 3 CH 2 C H C H 2 C H C H 3
N H C H 2 CH 3
CH 3
CH 2 CH 3
N H C H 2 CH 2 CH 3
D.
E.
F.
一、含官能团化合物的命名
请自学羧酸衍生物的命名
常见官能团的词头、词尾名称 ——
请参阅教材 P258
二、含官能团化合物的结构与物理性质
In all the compounds containing
oxygen,nitrogen and halogens,the
following intermolecular attractions
may exist,that may influence their
physical properties,
Boiling Points
Table,Comparative Boiling Points of
Alkanes,Ethers,Alcohols,and Amines(0C)
propane dimethyl ether ethanol ethanamine
-42.1 -23.7 78 16.6
butane ethylmethyl ether propanol propanamine
-0.5 10.8 97.4 47.8
pentane diethyl ether butanol butanamine
36.1 34.5 117.3 77.8
Boiling Points
1) Ethers generally have higher boiling
points than alkanes of comparable
molecular weight ------
because both van der Waals forces and
dipole-dipole interactions must be
overcome for an ether to boil
Boiling Points
2) Alcohols have much higher boiling
points than alkanes or ethers of
comparable molecular weight --------
Because in addition to van der Waals
forces and the dipole-dipole
interactions of the carbon-oxygen bond,
alcohols can form Hydrogen bonds.
Boiling Points
3) Primary and secondary amines also
form hydrogen bonds,so these amines
have higher boiling points than alkanes
and ethers with similar molecular
weight,
Boiling Points
4) Amines have lower boiling points than
alcohols with similar molecular weights.
Because nitrogen is not as electronegative
as oxygen,which means that the hydrogen
bonds between amine molecules are weaker
than the hydrogen bonds between alcohol
molecules,
Boiling Points
Table,Comparativ Boiling Points of
Alkanes and Alkyl halides
Y
H F Cl Br I
CH3-Y -161.7 -78.4 -24.2 3.6 42.4
CH3CH2-Y -88.6 -37.7 12.3 38.4 72.3
CH3CH2CH2-Y -42.1 -2.5 46.6 71.0 102.5
CH3CH2CH2CH2-Y -0.5 32.5 78.5 101.6 130.5
CH3-Y 1.6D 1.5D 1.4D 1.2D
Boiling Points
Both van der Waals forces and dipole-
dipole interaction must be overcome
for an alkyl halide to boil,
Polarizability indicates the case with
which an electron cloud can be
distorted,
The more polarizable the atom,the
stronger the van der Waals interactions.
Boiling Points
Problem 1:
Please explain the following facts:
Compounds bp(0C)
2-methylbutanamine 97
N-methyl-2-methylbutanamine 84
N,N-dimethyl-2-methylbutanamine 65
Boiling Points
Problem 2:
Please compare the boiling points of
ethers,alcohols,aldehydes,ketones
and carboxylic acids,esters,amides of
the similar molecular weight.
Solubility
General Rule,Like dissolves like
Each compound containing oxygen or
nitrogen has both a nonpolaar alkyl
group and a polar functional group,Is it
soluble in a nonpolar solvent or is it
soluble in water?
The answer depends on the size of the
alkyl group.
Solubility
Solubility of ethers in water
2C’s soluble
3C’s soluble
4C’s slightly soluble (10g/100g H2O)
5C’s minimally soluble (1.0g/100g H2O)
6C’s insoluble (0.25g/100g H2O)
Solubility
Solubility of alkyl halides in water
CH3F CH3Cl CH3Br CH3I
very soluble slightly slightly
CH3CH2F CH3CH2Cl CH3CH2Br CH3CH2F
soluble slightly slightly slightly
3C’s F 3C’s Cl 3C’s Br 3C’s I
slightly slightly slightly slightly
三、含氧、含氮杂环简介
参阅教材第十九章结构部分，请记住以下杂环母体环的中英文名称：
呋喃 噻吩 吡咯 噁唑 噻唑 咪唑
吡啶 吡喃 哒嗪 嘧啶 吡嗪三、含氧、含氮杂环简介
Aromatic Compounds Contaning
heteroatoms (O,N,S ----- sp2 H.)
Please indicate which lone pair of
electron is in p-orbital
O N
H
S N
三、含氧、含氮杂环简介
Biologically Important Heteroaromatics
------ Chlorophyll a
N
N
N
N
O
H
O
O O
O
Mg
三、含氧、含氮杂环简介
Biologically Important Heteroaromatics
------- Xanthopterin,Caffeine
N
N
N
N
O
O
NH 2
H
H
N
N N
N
O
O
H 3 C
CH 3
CH 3
四、金属有机化合物简介
1、与碱金属形成具有离子性的键
-—— 反应活性高
2、与第 II、第 III族原子 Mg,B,Al等形成特殊的共价键 ——三中心两电子键
—— 醚等 LewIs 碱可与之形成络合物而稳定这一类金属有机化合物
3、与第 IV,V族原子形成正常的共价键
—— 有一定的立体构型第三章重点讲授内容
一、含官能团化合物的命名
二、官能团化合物的结构和物理性质
三、含氧、含氮杂环化合物简介
四、金属有机化合物简介
1、有机化合物命名的一般步骤怎样？母体如何选择？各种基团（官能团）的英文词头或词尾的变化规律如何？
2、各种碳氢化合物的稳定性如何？芳香性与共振论是怎么回事？如何画极限共振结构式，并判断它们的能量高低？
3、化合物结构与物理性质的关系如何？
4、非共价弱作用力有哪些？
第二章碳氢化合物
Hydrocarbon
第二章重点讲解问题
1,碳氢化合物的命名（以烷烃和环烷烃为例）
2,碳氢化合物的稳定性
3,共轭烯烃、芳香性与共振论和分子轨道理论
4,碳氢化合物的物理性质与分子间作用力关系
2.1 碳氢化合物的分类与命名
2.1.1 Classification of hydrocarbon
Alkanes and Cycloalkanes
Alkenes (cis and trans) (Z and E)
Conjugated dienes
Aromatic hydrocarbons
Alkynes
2.1 碳氢化合物的分类与命名
2.1.2 Representing Molecules
Molecular formula CH4 H
a Stick figure H C H
a Lewis dot structure H
a Sawhorse representation
2.1 碳氢化合物的分类与命名
2.1.3 通式与不饱和度（环的数目）
Saturated Hydrocarbons,CnH2n+2
For a formula,CnHm
Degree of unsaturated= (2n+2-m)/2
If it is a cycloalkane,the degree of
unsaturated equals to the number of ring
2.1.4 Nomenclature
Common Name and Systematic Name
CH4 CH3CH3 CH3CH2CH3
Methane Ethane Propane
CH3CH2CH2CH3 CH3CHCH3
CH3
C,N,n-butane isobutane
S,N,Butane 2-methylpropane
2.1.4 Nomenclature
CH3CH2CH2CH2CH3 Pentane
CH3CHCH2CH3 isopentane,2-methylbutane
CH3
CH3
CH3CCH3 neopentane,2,2-dimethylpropane
CH3
2.1.4 Nomenclature
CH3CH2CH2CH2CH2CH3 hexane
CH3CHCH2CH2CH3 isohexane,2-methylpentane
CH3
CH3
CH3CCH2 CH3 neohexane,2,2-dimethylbutane
CH3
2.1.4 Nomenclature
CH3CH2CHCH2CH3 none 3-methylpentane
CH3
CH3CH-CHCH3 none 2,3-dimethylbutane
CH3 CH3
Alkyl Group R- (replacing,ane” with,yl”)
primary,secondary,tertiary,quaternary C,but
only primary,secondary,tertiary H
( see our text )
2.1.4 Nomenclature (IUPAC Rules)
Systematic Name (IUPAC Rules)
(IUPAC,International Union of Pure and Applied Chemistry)
1,Determine the number of carbon in the
longest continuous carbon chain----This chain is
called the parent hydrocarbon.
1 2 3 4 5 6 7 8
CH3CH2CHCH2CH2CH2CH2CH3 3-methyl Octane
CH3
CH3CHCH2CH2CH3 4-methyl Octane
CH2CH2CH2CH3
2.1.4 Nomenclature (IUPAC Rules)
2,Number the chain so that the
substituent gets the lowest possible
number,
CH3CH2CHCH2CHCH2CH2CH3 5-ethyl-3-methyloctane
CH3 CH2CH3 not 4-ethyl-6-methyloctane
because 3 < 4
CH2CH3
CH3CHCHCH2CH2CHCH3 3-ethyl-2,6-dimethylheptane
CH3 CH3 not 5-ethyl-2,6-dimethylheptane
because 3 < 5
2.1.4 Nomenclature (IUPAC Rules)
3,Cite the name of the alkyl substituent
before the parent hydrocarbon,---- A
number and a word are separated by a
hyphen; numbers are separated by a
comma,di,tri,tetra is used to express the
number of the same substituents
CH3CH2CHCH2CHCH3 2,4-dimethylhexane
CH3 CH3
2.1.4 Nomenclature (IUPAC Rules)
And list substituents in alphabetical order,
----,di,tri,tetra,sec,and tert” are ignored
in alphabetizing.,iso,neo,and cyclo” are
not ignored in alphabetizing.
3HC2HC CH3
CH3CH2CCH2CH2CHCHCH2CH2CH3 3,3,6-triethyl-7-methyldecane
3HC2HC CH2CH3
CH3
CH3CH2CH2CHCH2CH2CHCH3 5-isopropyl-2-methyloctane
CH(CH3)2
2.1.4 Nomenclature (IUPAC Rules)
4,If the same substituent number are
obtained in both directions,the first cited
group received the lower number.
CH3 3-ethyl-5-methylheptane
CH3CH2CHCH2CHCH2CH3 not
CH2CH3 5-ethyl-3-methylheptane
Cl 2-bromo-3-chlorobutane
CH3CHCHCH3 not
Br 3-bromo-2-chlorobutane
2.1.4 Nomenclature (IUPAC Rules)
5,If a compound had two or more chains
of the same length,the parent
hydrocarbon is the chain with the greatest
number of substituents.
CH3CH2CHCH2CH2CH3 CH3CH2CHCH2CH2CH3
CHCH3 CHCH3
CH3 CH3
3-ethyl-2-methylhexane not 3-isopropylhexane
(two substituents) (one substituent)
2.1.4 Nomenclature (IUPAC Rules)
6,If there are some complex substituents,
we can use the similar method to name
the substituents,
CH3CH2CHCH2CH2CH3 CH3CH2CH2CHCH2CH2CH3
1 2 1 2 3
CHCH3 CH2CHCH3
CH3 CH3
3-isopropylhexane or 4-isobutylheptane or
3-(1-methylethyl)hexane 4-(2-methylpropyl)heptane
2.1.4 Nomenclature (IUPAC Rules)
当一个饱和支链无环烃具有相同长度的链可作为主链时，则选择的顺序为：
1）具有侧链数目最多的链
4-propyl-2,3,5-
trimethylheptane
not
3-methyl-4-(1,2-
dimethylpropyl)heptane
C H 3 C H 2 C H C H C H
C H 3 C H
2
C H 3
C H C H 3
C H 3
C H 2 C H 3
2.1.4 Nomenclature (IUPAC Rules)
2）侧链具有最低位次的链
2,5-dimethyl-4-(1-
methylpropayl)heptane (not 3,4,5)
C H C H 2 - C H C H 3
C H C H 3
C H 3 C H 2 C H
C H 2 C H 3
C H 3 C H
3
2.1.4 Nomenclature (IUPAC Rules)
3）在较短的侧链中，具有碳原子数目最多的链
（各侧链数分别为 111288和 111189）
3-ethyl- 5,9,11-trimethyl-7,7-di(2,4-
dimethylhexyl)tridecane
C
CH 2 CHCH 2 CHCH 2 CH 3
CH 2 CHCH 2 CHCH 2 CH 3
CH 3 CH 2 CHCH 2 CHCH 2
CH 3 CH 2 CHCH 2 CHCH 2
CH 3 CH
3
CH 3 CH 3 CH 3 CH 2 CH 3
CH 3 CH 3
课堂练习：
请给出上述结构的中英文 IUPAC命名
1,4-(1-ethylpropyl)-
2,5,6,6-tetramethyloctane
2,1-ethyl-2-mehylcyclopentane
C H 3 C H 2 C - C H C H C H 2 C H C H 3
C H 3 C H C H
2 C H 3
C H 3C H 3
C H 2 C H 3
C H 3
C H 2 C H 3
C H 3
1,2,
2.1.4 Nomenclature (IUPAC Rules)
7,For cycloalkane,(skeletal structure)
1) In the case of a cycloalkane with an
attached alkyl substituent,the ring is the
parent hydrcarbon unless the substituent
has more carbons than the ring,
A,Isopropylcyclohexane
B,1-cyclobutylpentane
CH 2 ( C H 3 ) 2 CH
2 CH 2 CH 2 CH 2 CH 3A,B.
2.1.4 Nomenclature (IUPAC Rules)
2) If the ring has two different substituents,they
are cited in alphabetical order and the number 1
position is given to the first cited substituent.
A,1-ethyl-3-methylcyclopentane
B,1,3-dimethylcyclohexane
CH 2 CH 3H 3 C CH 3H 3 CA,B.
2.1.4 Nomenclature (IUPAC Rules)
3) If there are more than two substituents on the
ring,give the number 1 position to the
substituent that result in a second substituent
getting as low a number as possible.
A,1,1,2-trimethylcyclopentane
(not 1,2,2; not 1,1,5)
B,4-ethyl-2-methyl-1-propylcyclohexane
not 1,3,4,(2<3); not 5,1,2,(4<5)
CH 3
CH 3
CH 3
H 3 CH 2 CH 2 C
H 3 C CH 2 CH 3A,B,
以下内容请自学：
Nomenclature of Alkenes (cis and trans)
(Z and E)
Alkynes
Conjugated dienes
Aromatic hydrocarbons
2.2 碳氢化合物的稳定性
2.2.1 Saturated hydrocarbons ---- Alkanes
relatively stable
2.2.2 Cycloalkanes ---- Ring Strain
Instability of three- and four-member rings
---- due to angle strain
1 0 9,5 0
60 0 90
0
2.2 碳氢化合物的稳定性
2.2.3 Alkenes ---- Pi Bonding
The functional group is the center of
reactivity of a molecule,Carbon-carbon
double bond (C=C) is the functional group
of alkenes,
Strength of Bond,C-C 347.3 kJ/mole
C=C 610.9 kJ.mole
a Pi Bond is weaker than a Sigma Bond
2.2 碳氢化合物的稳定性
2.2.4 Alkynes ---- Pi Bond
Strength of Bond,C-C 347.3 kJ/mole
C=C 610.9 kJ.mole
C=C 836.8 kJ/mole
Pi Bond in C=C,263.6 kJ/mole
Pi Bond in C=C,244.8 kJ/mole
an alkyne is less reactive than an alkene
Why?（ Please think it out by yourself）
2.2 碳氢化合物的稳定性
Class of dienes,conjugated
isolated
cumulated
Heat of Formation:
n C + n H2 Cn H 2n + h eat ( Hf 0 )
Gr ap h i t e Gas
2.2 碳氢化合物的稳定性
The difference between the heats reflects the
difference in stability between the
nonconjugated and conjugated dienes
2.2 碳氢化合物的稳定性
2.2.5 Aromatic hydrocarbons
Benzene,with relatively few hydrogens
comparing with aliphatic compound,is a
particularly stable compound because it has an
unusually large resonance energy 151kJ/mole)3 H 2
H
0
- 4 9,3 k c a l / m o l e
H
0
- 2 8,4 k c a l / m o l e
H 2
Questions:
Why is a conjugated diene more stable
than an isolated diene?
Why is benzene a particularly stable
compound?
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Conjugated Dienes
1,Single bond between C2-C3 formed by
sp2-sp2 overlap,the length of the bond is
shorter,therefore the bond is stronger.
CH3--CH3 Csp3-Csp3 154pm
CH2=CH--CH3 Csp2-Csp3 150pm
CH2=CH--CH=CH2 Csp2-Csp2 146pm
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
2,Structure of Conjugated Dienes:
3,The conjugated diene had delocalized
electrons,We can draw the resonance structure:
resonance hybrid:
H 2 C CH CH CH 2
CH 2 - - C H = C H - - C H 2 C H2 = C H - - C H = C H 2 C H2 - - C H = C H - - C H 2+ +- -
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
分子轨道理论阐述 1,3-丁二烯的结构
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Structure of Benzene
1,All the carbon are
sp2 hybridized
2,The p orbital on each carbon can
overlap with two adjacent p orbitals.
3,p-electrons in benzene are delocalized,
we call such compound to have
resonance.
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
电子离域与共振
上述结构较好地表示了电子的离域，但是却无法告诉我们该结构中含有多少双键。
因此化学家常用共振结构来表示。
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Some basic concepts
1,A compound with delocalized electrons is said
to have resonance
2,The approximate structure using localized
electrons is called a resonance contributor,a
resonance structure,or a contributing
resonance structure
3,The catual structure,drawn using delocalized
eletrons,is called a resonance hybrid.
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Rules for Drawing Resonance Contributors
1,Only electrons move,The nuclei of the atoms
never move
2,The only electrons that can move are π
electrons and nonbonding electrons
3,The total number of electrons in the molecule
does not change,neither do the numbers of
paired and unpaired electrons
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
4,The electrons can be moved in one of the
following ways
1) Move π electrons toward a positive charge or
toward a π bond
H 3 C H C C
H
C H C H 3CH 3 CH = CH - - - CH CH 3 CH 3 CH - - - CH = CH CH 3
+ +
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
2) Move a nonbonding pair of electrons toward a
π bond
CH 3 C H = C H - - - O - - - C H 3 C H 3 C H - - - C H = O - - - C H 3
H 3 C H C C
H
O CH 3
r e s o n a n c e c o n t r i b u t o r s
r e s o n a n c e h y b r i d
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
3,Move a single nonbonding electron toward a
π bond
H 3 C C
H
C
H
CH 2 H 3 C C
H
C
H
CH 2
H 3 C C
H
C
H
CH 2
r e s o n a n c e c o n t r i b u t o r s
r e s o n a n c e h y b r i d
课堂练习：
请给出上述结构的中英文 IUPAC命名
1,4-(1-ethylpropyl)-
2,5,6,6-tetramethyloctane
not 3,3,4,7-tetramethyl-5-(1-ethylpropyl)-
2,1-ethyl-2-mehylcyclopentane
C H 3 C H 2 C - C H C H C H 2 C H C H 3
C H 3 C H C H
2 C H 3
C H 3C H 3
C H 2 C H 3
C H 3
C H 2 C H 3
C H 3
1,2,
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
2,Structure of Conjugated Dienes:
3,The conjugated diene had delocalized
electrons,We can draw the resonance structure:
resonance hybrid:
H 2 C CH CH CH 2
CH 2 - - C H = C H - - C H 2 C H2 = C H - - C H = C H 2 C H2 - - C H = C H - - C H 2+ +- -
2.3 共轭烯烃、芳香性与共振论和分子轨道理论
Aromaticity and Huckel’s Rule
Benzene ------ perticularly stable
because of the resonance energy
But cyclobutadiene and
cyclooctatetraene containscyclic two
or four Pi-bond,they are not stable,
Aromaticity and Huchel’s Rule
In 1938,a German chemist Erich
Huckel recognized the difference
between them and generalized this
obeservation into Huckel’s Rule
------- any plannar,cyclic,conjugated
system containing (4n+2) Pi electrons
(where n is an integer) experiences
unusual aromatic stabilization
Aromaticity and Huchel’s Rule
Molecular Orbital theory
------- in benzene6
Aromaticity and Huchel’s Rule
Molecular Orbital theory
------- in cyclooctatetraene
8
Aromaticity and Huchel’s Rule
Other member rings
0
-1
-2
1
2
0,6 1 8
- 1,6 1 8
1,2 4 7
-,4 4 5
- 1,8 0 2
1,4 1 4
- 1,4 1 4
Aromaticity and Huchel’s Rule
Other Aromatic molecules:
1,6-桥连 [10]-轮烯
[14]-轮烯,[18]-轮烯,[22]-轮烯
（请思考为什么 [10]-轮烯没有芳香性）
+
++ - - - ++
2.4 碳氢化合物的物理性质
2.4.1,Boiling Points
Depend on the strength of the attractive
forces between the individual molecules
In Alkanes,C-C C-H nonpolar bonds
van der Waals forces ---- induced dipole-
induced-dipole interactions
C=O,C-O polar bonds
dipole-dipole interaction
2.4 碳氢化合物的物理性质
Van der Waals forces are the weakest of
all the intermolecular attraction
It depends on the area of contact between
the molecules
The boiling points of alkanes increase as
their size increase
And a branched compound has a
relatively lower boiling point
2.4 碳氢化合物的物理性质
2.4.2,Melting Points
Packing influences the melting point of a
compound
Packing is a property that determines how well
the individual molecules in a sold fit together in
the crystal lattice
The tighter the fit,the more energy required to
break the lattice and melt the compound,
2.4 碳氢化合物的物理性质
2.4.3 Solubility
General Rule,Like dissolves like
第二章重点讲解问题
1,碳氢化合物的命名（以烷烃和环烷烃为例）
2,碳氢化合物的稳定性
3,共轭烯烃、芳香性与共振论和分子轨道理论
4,碳氢化合物的物理性质与分子间作用力关系第三章 含官能团化合物命名、结构和物理性质第三章重点讲授内容
一、含官能团化合物的命名
二、官能团化合物的结构和物理性质
三、含氧、含氮杂环化合物简介
四、金属有机化合物简介一、含官能团化合物的命名
1,Alkyl Halides
In the IUPAC system,alkyl halides are
named as substituted alkanes,alkenes
or alkynes,
The substituent prefix names for the
halogens replaces the,ine”ending in
the name of the element with,o”
------ floro,chloro,bromo,iodo
一、含官能团化合物的命名
A,2-bromo-5-methylheptane
B,1-chloro-6,6-dimethyl-3-heptene
CH 3 CH 2 C H C H 2 CH 2 C H C H 3
CH 3
Br
A,B,CH 3 CCH 2 C H =C H C H 2 CH 2 Cl
CH 3
CH 3
一、含官能团化合物的命名
C,1,6-dichloro(-1-)cyclohaxene
D,6-bromo-3-chloro-4-methyl (-1-)
cyclohexene
E,(Z)-2-bromo-4-ethyl-7-methyl-4-
octene
Cl
Cl Cl
CH 3Br
C,D,CH 3 CHCH 2
CH 3
Br
C C
CH 2 CHCH 3
CH 2 CH 3H
E.
一、含官能团化合物的命名
2,Ethers
The IUPAC system names an ether as
an alkane,alkene or alkyne that has an
RO subsituent,
The substituents are named by
replacing the,yl” ending in the name
of the alkyl subtituent with,oxy”
一、含官能团化合物的命名
A,1-ethoxy-3-methyl-2-pentene
B,1,4-diisopropoxybutane
A,CH 3 CH 3 C= CH C H 2 O CH 2 CH 3
CH 3 CH O C H 2 CH 2 CH 2 CH 2 O CH C H 3
CH 3 CH 3
CH 3
B.
一、含官能团化合物的命名
3,The following rules are used when
naming a compound that has a
functional group suffix ( Alcohols,
aldehydes,ketones,carboxylic acid
and their derivatives,amines)
一、含官能团化合物的命名
1) The parent hydrocarbon is the
longest continuous chain containing
the functional group,and is numbered
in the direction that given the
functional group suffix the lowest
possible number.
一、含官能团化合物的命名
A,2-ethyl-1-pentanol or
2-ethylpentan-1-ol
B,2-propoxy-1-ethanol or
2-propoxyethan-1-ol
CH 3 CH 2 CH 2 CHCH 2 OH
CH 2 CH 3
A.
B,CH
3 CH 2 CH 2 O C H 2 CH 2 OH
一、含官能团化合物的命名
2) If there is a functional group suffix
and a substituent,the functional group
suffix gets the lowest number,
4-methyl-1-pentanol
H O C H 2 CH 2 CH 2 CH CH 3
CH 3
一、含官能团化合物的命名
3) If the same number for the functional
group suffix is obtained in both
directions,the chain is numbered in the
direction that gives a substituent the
lowest possible number.
2-methyl-3-pentanol
not
4-methyl-3-pentanolCH 3 C H C H C H 2 CH 3
CH 3
HO
一、含官能团化合物的命名
4) If there is more than one substituent,
the substituents are cited in
alphabetical order.
6-bromo-3-ethyl-2-hexen-1-ol
H O C H 2 C H = C C H 2 CH 2 CH 2 Br
CH 2 CH 3
一、含官能团化合物的命名
Remember that the name of a
subsitituent is stated before the name
of the parent hydrocarbon,and the
functioal froup suffix is stated after the
name of the parent hydrocarbon.
一、含官能团化合物的命名
A,5-hydroxypentanal
B,4-penten-2-one (allylmethyl ketone)
C,4-methyl-2-oxo-3-hexanoic acid
H O C H 2 CH 2 CH 2 CH 2 C H OA,
B,CH
3 C C H 2 C H = C H 2
O
C,CH 3 CH 2 C H C H 2 C C O O H
CH 3 O
一、含官能团化合物的命名
A,Benzenecarbaldehyde (benzaldehyde)
B,Cyclohexylcarboxylic acid
C,3-phenylpropanoic acid
D,2-bromo-4-methylcyclohexanol
C O O H
CH 2 CH 2 C O O H
C H O B.
OH
C,Br
H 3 C
A.
D.
一、含官能团化合物的命名
A,1-butanamine or butan-1-amine
B,N-ethyl-3-hexanamine or
N-ethylhexan-3-amine
C,N-ethyl-N-methyl-1-propanamine
or N-ethyl-N-methylpropan-1-amine
CH 3 CH 2 CH 2 CH 2 NH 2 CH 3 CH 2 CH CH 2 CH 2 CH 3
N H CH 2 CH 3CH
3 CH 2 CH 2 N CH 2 CH 3
CH 3
A,B.
C.
一、含官能团化合物的命名
D,3-ethyl-N-methyl1-butanamine
E,N-ethyl-5-methyl-3-hexanamine
F,2-ethyl-N-propylcyclohexanamine
CH 3 C H C H 2 CH 2 N H C H 3
Cl
CH 3 CH 2 C H C H 2 C H C H 3
N H C H 2 CH 3
CH 3
CH 2 CH 3
N H C H 2 CH 2 CH 3
D.
E.
F.
一、含官能团化合物的命名
请自学羧酸衍生物的命名
常见官能团的词头、词尾名称 ——
请参阅教材 P258
二、含官能团化合物的结构与物理性质
In all the compounds containing
oxygen,nitrogen and halogens,the
following intermolecular attractions
may exist,that may influence their
physical properties,
Boiling Points
Table,Comparative Boiling Points of
Alkanes,Ethers,Alcohols,and Amines(0C)
propane dimethyl ether ethanol ethanamine
-42.1 -23.7 78 16.6
butane ethylmethyl ether propanol propanamine
-0.5 10.8 97.4 47.8
pentane diethyl ether butanol butanamine
36.1 34.5 117.3 77.8
Boiling Points
1) Ethers generally have higher boiling
points than alkanes of comparable
molecular weight ------
because both van der Waals forces and
dipole-dipole interactions must be
overcome for an ether to boil
Boiling Points
2) Alcohols have much higher boiling
points than alkanes or ethers of
comparable molecular weight --------
Because in addition to van der Waals
forces and the dipole-dipole
interactions of the carbon-oxygen bond,
alcohols can form Hydrogen bonds.
Boiling Points
3) Primary and secondary amines also
form hydrogen bonds,so these amines
have higher boiling points than alkanes
and ethers with similar molecular
weight,
Boiling Points
4) Amines have lower boiling points than
alcohols with similar molecular weights.
Because nitrogen is not as electronegative
as oxygen,which means that the hydrogen
bonds between amine molecules are weaker
than the hydrogen bonds between alcohol
molecules,
Boiling Points
Table,Comparativ Boiling Points of
Alkanes and Alkyl halides
Y
H F Cl Br I
CH3-Y -161.7 -78.4 -24.2 3.6 42.4
CH3CH2-Y -88.6 -37.7 12.3 38.4 72.3
CH3CH2CH2-Y -42.1 -2.5 46.6 71.0 102.5
CH3CH2CH2CH2-Y -0.5 32.5 78.5 101.6 130.5
CH3-Y 1.6D 1.5D 1.4D 1.2D
Boiling Points
Both van der Waals forces and dipole-
dipole interaction must be overcome
for an alkyl halide to boil,
Polarizability indicates the case with
which an electron cloud can be
distorted,
The more polarizable the atom,the
stronger the van der Waals interactions.
Boiling Points
Problem 1:
Please explain the following facts:
Compounds bp(0C)
2-methylbutanamine 97
N-methyl-2-methylbutanamine 84
N,N-dimethyl-2-methylbutanamine 65
Boiling Points
Problem 2:
Please compare the boiling points of
ethers,alcohols,aldehydes,ketones
and carboxylic acids,esters,amides of
the similar molecular weight.
Solubility
General Rule,Like dissolves like
Each compound containing oxygen or
nitrogen has both a nonpolaar alkyl
group and a polar functional group,Is it
soluble in a nonpolar solvent or is it
soluble in water?
The answer depends on the size of the
alkyl group.
Solubility
Solubility of ethers in water
2C’s soluble
3C’s soluble
4C’s slightly soluble (10g/100g H2O)
5C’s minimally soluble (1.0g/100g H2O)
6C’s insoluble (0.25g/100g H2O)
Solubility
Solubility of alkyl halides in water
CH3F CH3Cl CH3Br CH3I
very soluble slightly slightly
CH3CH2F CH3CH2Cl CH3CH2Br CH3CH2F
soluble slightly slightly slightly
3C’s F 3C’s Cl 3C’s Br 3C’s I
slightly slightly slightly slightly
三、含氧、含氮杂环简介
参阅教材第十九章结构部分，请记住以下杂环母体环的中英文名称：
呋喃 噻吩 吡咯 噁唑 噻唑 咪唑
吡啶 吡喃 哒嗪 嘧啶 吡嗪三、含氧、含氮杂环简介
Aromatic Compounds Contaning
heteroatoms (O,N,S ----- sp2 H.)
Please indicate which lone pair of
electron is in p-orbital
O N
H
S N
三、含氧、含氮杂环简介
Biologically Important Heteroaromatics
------ Chlorophyll a
N
N
N
N
O
H
O
O O
O
Mg
三、含氧、含氮杂环简介
Biologically Important Heteroaromatics
------- Xanthopterin,Caffeine
N
N
N
N
O
O
NH 2
H
H
N
N N
N
O
O
H 3 C
CH 3
CH 3
四、金属有机化合物简介
1、与碱金属形成具有离子性的键
-—— 反应活性高
2、与第 II、第 III族原子 Mg,B,Al等形成特殊的共价键 ——三中心两电子键
—— 醚等 LewIs 碱可与之形成络合物而稳定这一类金属有机化合物
3、与第 IV,V族原子形成正常的共价键
—— 有一定的立体构型第三章重点讲授内容
一、含官能团化合物的命名
二、官能团化合物的结构和物理性质
三、含氧、含氮杂环化合物简介
四、金属有机化合物简介
