Introduction of organic chemistry
SORACHAI SAE-LIM
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SORACHAI SAELIM
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-The human body is largely composed of organic compounds-Organic chemistry plays a central role in medicine, bioengineering etc.
Organic Chemistry
SORACHAI SAELIM
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ORGANIC CHEMISTRY
Organic chemistry is the study of the compounds of carbon. The compounds of carbon constitute the central chemicals of all living thing on this planet.
CHO
HO
OH
O
O
H
Gallic acid
O
OHOOH
OHCH2OH
O
HO
HO
OH
OH
SORACHAI SAELIM
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Mangifera odorata
Natural Products
SYNTHESIS
O
OH O
HO
OH
OH
O
OH O
HO
O
O
H
DPPH DPPH:H
NNO2O2N
NO2
N
N:HNO2O2N
NO2
N
DPPH DPPH:H
O
OH O
HO
OO
MF 11
+
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Electronegativity
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Ionic Bonds
Covalent Bonds
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Formal charge
Ammonium ion (NH4)+
Nitrate ion (NO3)-
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A Summary of Formal Charges
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Resonance
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Atomic Orbitals
-Orbital: a region in space where the probability of finding an electron is large
-Only s and p orbitals are very important in organic chemistry
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Electronic Configurations of Some Second Row Elements
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Electronic Configurations of Atoms1S2
2S2
3S2
4S2
5S2
6S2
7S2
2p6
3p6
4p6
5p6
6p6
7p6
3d10
5d10
6d10
7d10
4d10 4f14
6f14
5f14
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Bonding Molecular Orbitals
Antibonding molecular orbital
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The sharing of electrons in a covalent bond occurs by overlap of the individual atomic orbitals. Head-on overlap between energetically compatible orbitals generates sigma (s) bonds,
while sideways overlap (typically from adjacent p orbitals) generates pi (p) bonds. Example of p-bond formation between atoms "A" and "B" is shown.
Example of sigma bond formation between atoms "A" and "B" is shown.
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The Structure of Methane and Ethane: sp3
Hybridization
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Hybridization of Carbon
-Carbon may from single, double and triple bonds.
-Let’ s look at the electron configuration of ground state (lowest energy state) carbon:
6c 1s2 2s2 2p2,
2s 2px 2py 2pz
6c electron configuration of ground state = ?????
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ground state
2s
2px 2py 2pz2px 2py 2pz
Excited state
Hybridization excited
2s 2px 2py 2pz
Sp3 -Hybridization
6c
2s 2px 2py 2pz
2s
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CH4H H H H
2s 2px 2py 2pz
Sp3 -Hybridization
Carbon-hybridization
C-H sigma bond = ….
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The structure of Borane hydride (BH3)
Sp2 -Hybridization
5B
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ground state2s
2px 2py 2pz
excited
5B
2s 2px 2py 2pz
Sp2 -Hybridization
2s 2px 2py 2pz
2px 2py 2pz
Excited state
Hybridization
2s
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H H H
Sp2 -Hybridization
BH3
Borane-hybridization
B-H sigma bond = …………………
2s 2px 2py 2pz
H
H
H
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The structure of Beryllium hydride (BeH2)
Sp -Hybridization
4Be
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The structure of Ethane (C2H6)
Hybridization of Carbon= ?????
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The structure of Ethene (C2H4)
Hybridization of Carbon= ?????
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The structure of Ethyne (C2H2)
Hybridization of Carbon= ?????
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Bond Lengths of Ethyne, Ethene and Ethane
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Ammonia
The bond angles are about 107o and not 109.5o
because the non-bonding electrons in effect are larger and compress the nitrogen-hydrogen bond
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Water
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Representations of Structural Formulas
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Sample Problem
Rewrite each of the following condensed structural formulas, as dash formulas as :
C
H
H
H
C
H
C
C
H
H
C
C
H
HH
HH
C
H
H
H
H
H
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Bond-Line Formulas
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SORACHAI SAELIM
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Write dash formulas for each of the following bond-line formulas:
OH
OH
OH
A.
B.
C.
D.
E.
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Three-Dimensional Formulas
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Polar Covalent Bonds
Polar covalent bonds occur when a covalent bond is formed between two atoms of differing electro negativities
•The more electronegative atom draws electron density closer to itself•The more electronegative atom develops a partial negative charge
(d-) and the less electronegative atom develops a partial positive charge (d+)
•A bond which is polarized is a dipole and has a dipole moment•The direction of the dipole can be indicated by a dipole arrow
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Physical Properties and Molecular Structure
-The strength of intermolecular forces (forces between molecules) determines the physical properties (i.e. melting point, boiling point and solubility) of a compound
-Stronger intermolecular forces result in high melting points and boiling points
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Physical Property
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Ion-Ion ForceDipole-Dipole Forces
Hydrogen Bonds
van der Waals Forces (London or Dispersion
Forces)
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Solubilitie
Water dissolves ionic solids by forming strong dipole-ion interactions
Generally: like dissolves like
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Generally: like dissolves like
A large alkyl group can overwhelm the ability of the polar group to solubilize a molecule in waste
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Summary of Attractive Electric Force
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Functional Groups
-Functional group families are characterized by the presence of a certain arrangement of atoms called a functional group
-A functional group is the site of most chemical reactivity of a molecule
H
HO H
O
OH
H
H
3
1
19
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1417
22 24
26
27
21
18
28
29 30
XCoumarinsO
O
O
OH
OH
O
HO
HO
XBenzenoides
CHO
HO
OH
O
O
H
Gallic acid
O
OHOOH
OHCH2OH
O
HO
HO
OH
OH
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C C
C C
C C
OR
OR R
H
CR H
O
Alkane
Alkene
Alkyne
Alcohol
Ether
Aldehyde
CR OH
O
CR O
O
R
CR NH2
O
NH2R
Carboxylic acid
Amide
Amine
Ester
c
O
R R1
Ketone
Functional Groups in Organic Chemistry
A functional groups is the part of a molecule where most of its chemical reactions occur.
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จงเติมค าตอบ1.1 จากรปูโครงสรา้งข้างต้น จงวงกลมหมู่ฟังก์ชันของสารประกอบนี้ พร้อมทั้งบอกว่าเป็น สารประกอบประเภทใด (2.0 คะแนน)1.2 คารบ์อนตรงต าแหน่งลูกศร I จัดเป็นคาร์บอนชนิด...............................................(0.5 คะแนน)1.3 คารบ์อนตรงต าแหน่งลูกศร II จัดเป็นคาร์บอนชนิด..............................................(0.5 คะแนน)
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propene (propylene)
C C HH Ethyne (acetylene)
Alkenes are hydrocarbons that contain carbon-carbon double bond as their functional group.
Alkynes are hydrocarbons with carbon-carbon triple bond as their functional group.
C C Alkyne
C C Alkene
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CH3-CH2-OH ETHANOL
OR H Alcohol
Alcohols are organic compounds that contain the hydroxyl group (-OH) as their function group.
Alcohols are classified into three groups; primary (1o), secondary (2o), or tertiary (3o) alcohols.
This classification is also based on the degree of substitution of the carbon to which the hydroxyl group is directly attached.
OH
OH
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OR R Ether
Ethers are composed of two alkyl groups bonded to an oxygen atom. The general formula for an ether is R-O-R’ (The symbol R’ represents another alkyl group, either the same as or different from the first).
CH3-O-CH3 dimethyl ether
O CH3Cyclohexyl methyl ether
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CR H
O
Aldehyde CR R1
O
KetoneO
The carbonyl group
An aldehyde has one alkyl group and a hydrogen atom boned to the carbonyl group.
A ketone has two alkyl groups boned to the carbonyl group.
R C-H
O
R C-R
O
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CR OH
O
Carboxylic acid
CR O
O
R Ester
Carboxyl group
Carboxylic acids contain the carboxy group, -COOH, as their functional groups.
An acid derivative with an alkyl group replacing the acid proton;
CR O
O
R EsterCR OH
O
Carboxylic acid
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NH2R Amine
Amines are alkylated derivatives of ammonia.
This classification is based on the number of organic groups that are amines are alkylatedto the nitrogen atom:
Amines are classified as primary, secondary, or tertiary amines.
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CR NH2
O
Amide
Amides are acid derivatives that result from a combination of an acid with ammonia or an amine.
Proteins have the structure of long-chain, complex amides.
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Alkyl Halide
In alkyl halides, halogen (F, Cl, Br, I) replaces the hydrogen of an alkane
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