有机化学英文课件-烷烃和环烷烃英文课件

Q 1 Write structural formulas or skeletal structures (simplified line structures) for the isomeric hexanes (C6H14).
CH3CH2CH2CH2CH2CH3
CH3CHCH2CH2CH3 CH3CH2CHCH2CH3
I. Structure II. Nomenclature III. Properties
Ⅰ. Structure
1. sp3 hybridization
C: 1s2; 2s22p2
Excited2ss1ta2tpe3 2s1 2p3
sp3
Basic state 2s2 2p2
tetrahedral shape
C : be grouped by the number of carbon
atoms it attached.
primary carbon，1° secondary carbon，2° tertiary carbon ，3° quaternary carbon ，4°
1°CH3 C1°H3—C2°H2—C3°H—C2°H2—C4—°C1H°3
Butane(C4H10)
Pentane(C5H12)
2. General formula
General formula: CnH2n+2 CH4, CH3CH3, CH3CH2CH3, CH3CH2CH2CH3……
Homolog has similar chemical properties with different reacting rate, but their physical properties vary with the number of carbon atoms. The first member of homologous series often has special property.
CH4 takes a tetrahedron shape. Ball-stick model of methane
Staut model of methane
s-sp3 s bond by head to head overlap (see remark) 109.5
o
sp3 hybridization and structure of methane
Nature ofσbond: ① symmetrical about the bond-axis; ② firm and not easy to break; ③σ bond can rotate around the bond-axis
Ethane (CH3CH3)
s bond : rotate freely ； bigger overlap degree; higher stability, lower polarity.
1°CH3
1°CH3
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Primary H ( 1ºH ): those attach to 1ºcarbon
H: Secondary H ( 2ºH ): those attach to 2ºcarbon
Cis-trans ~
Enantio-
merism
Conformational ~
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(1) Carbon-chain isomerism:
C5H12 :
CH3CH2CH2CH2CH3
CH3 CH3CHCH2CH3
CH3 CH3-C-CH3
CH3
n-Pentane iso-Pentane neo-Pentane
Chapter 2
Alkanes and Cycloalkanes
烷烃和环烷烃
Section 1 Alkanes
Section 2 Cycloalkanes
Definition and Classification of Hydrocarbons
Alkanes
Saturated CH3CH3
Aliphatic ~
Alicyclic
Hydrocarbon
is only composed of carbon and hydrogen.
Alkenes Unsaturated CH2=CH2
Alkynes
CH ≡CH
Aromatic ~
Section 1 Alkanes
Alkane is one kind of hydrocarbon in which all of the carbon are bound to each other and hydrogen by single (s) bonds.
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3. Isomerism of alkanes
Constitutional isomerism
The atoms are
Isomerism
linked together in different way
Carbon-chain ~ Functional ~ Positional ~
Stereo- Configurational ~ isomerism
CH3
CH3
CH3 CH3CHCHCH3
CH3
CH3 CH3CCH2CH3
CH3
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Q 2 Identify as same or isomer the relationship between structure (a) and structure (b), (c), and (d).
CH3CHCH2CHCH2CH3
CH3 CH3 (a)
CH3
CH2CHCH2CHCH3
CH3
CH3
(b)
CH3
CH3CHCHCH2CH2 CH3 CH3 (c)
CH3CHCH2CHCH3 CH3 CH2CH3 (d)
A: (b) same, (c) isomer, and (d) same.
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Classification of C and H
C－Cσbond formed by head to head
near 109.5oC(tetrahedral)H s bonFra bibliotek H HH
154pm
H
H
Bonding of alkanes
All carbons are hybridized by sp3 All bonds are σ-bonds All bond angles are about 109°28’