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ORGANIC CHEMISTRYORGANIC CHEMISTRY
1.31.3 The chemistry of carbon / hydrogen containing compounds
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THE SIMPLEST TYPE OF ORGANIC COMPOUNDS
HYDROCARBONSHYDROCARBONS
HYDROCARBONSHYDROCARBONS - CONTAIN ONLY C, H
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HYDROCARBONSHYDROCARBONS
C CC C
C
H
HH
H
HH
H H
H
H
HH C C
C
CC
H
H
HH
HH
H
HH H
H
H
C CH
CH
C
HH
H
HH
H
C C CH HH
HC C C CH
HH
CH
H
H
HH
H C C C CH
H H
HH
H H
ALKYNESat leastonetriplebond
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COMMON HYDROCARBON TYPESCOMMON HYDROCARBON TYPES
Saturatedhydrocarbons
Unsaturated hydrocrabon
onlysinglebonds
at leastonedoublebond
C CC C
C
H
HH
H
HH
H H
H
H
HH C C
C
CC
H
H
HH
HH
H
HH H
H
H
C CH
CH
C
HH
H
HH
H
C C CH HH
HC C C CH
HH
CH
H
H
HH
H C C C CH
H H
HH
H H
ALKYNESat leastonetriplebond
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One or more H’s are replaced with an atom of O, N, S, F, Cl, Br, I
HYDROCARBONHYDROCARBON DERIVATIVESDERIVATIVES
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HYDROCARBON DERIVATIVESHYDROCARBON DERIVATIVES
C CC C
C
H
H
H
H
HH
H H
H
H
H
Cl
C CC C
C
H
H
H
H
HH
H H
H
H
H
OH
C CC C
C
H
H
H
H
HH
H H
HH
O
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Fig. 1.2 Terms for organic compounds.
Saturated Hydrocarbons cont’d
3-6)
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C CC C
C
H
H
H
H
HH
H H
H
H
H
HC C
C
C
C
H
H
H
H
H
H
H
H
H H
H
H
C C
H
CH
C
H
H
H
HH
H
C C CH H
H
H
C C C C
H
H
H
C
H
H
H
H
H
H C C C C
H
H H
H
H
H H
1.4 Alkanes
• Acyclic (no rings) = alkane
• Cyclic (contains rings)
Section 1.12 C
CC
C
CC
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1.4 Alkanes (cont.)
Are acyclic “saturated” hydrocarbons.
Contain only single bonds C-C
Every carbon is sp3 (tetrahedral) General formula of alkanes is CnH2n+2
CH4
C2H6
C3H8
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←Fig. 1.3 Molecular structures of (a) methane, (b) ethane, and (c) propane, the three simplest alkanes.
1.4 Alkanes
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Expanded (Lewis structure)
1.5 Structural formulas
H H H H H H | | | | | |H-C-H H-C-C-H H-C-C-C-H | | | | | | H H H H H H
Methane Ethane Propane
THESE TAKE A LOT OF SPACE TO DRAW
THEY TAKE A LONG TIME TO DRAW
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Condensed (easier and faster to draw)
1.5 Structural formulas
Methane CH4
Ethane CH3-CH3
Propane CH3-CH2-CH3
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Condensed
1.5 Structural formulas
Octane: CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH3
CH3-(CH2)6-CH3More condensed
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1.6 Alkane Isomerism
Branched carbon chain (acyclic)
CH3 |CH3-CH-CH2-CH2-CH2-CH2-CH3
Linear carbon chain
Octane: CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH3
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CONSTITUTIONAL ISOMERISM
• Same molecular formula, different connectivity of the atoms
• As the #C increase the #isomers increases very rapidly (Table 1.1)
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C C
H
HH
H
H
H
1.7 Conformations of alkanes1.7 Conformations of alkanes
MOST ATOMS ATTACHEDBY A SINGLE BOND ARE
FREE TO ROTATE AROUNDTHE BOND
The relative orientation of the atoms is called a CONFORMATION
HOW MANY CONFORMATIONS ARE THERE?
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SYN ANTI
GAUCHE
CONFORMATIONS OF BUTANECONFORMATIONS OF BUTANE
GAUCHE
ECLIPSED ECLIPSED
SAWHORSE PROJECTIONS OF PREVIOUS SLIDE
CH3
HH
HH
CH3
CH3 CH3H
HHH
CH3H
CH3
H
HH
CH3
CH3
H
HH
H
CH3
H
H
HCH3
H
CH3 H
HHH
CH3
CC
C C
C C C C
C C
CC
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I nternational
U nion of
P ure and
A pplied
C hemistry
1. 8 IUPAC RULES1. 8 IUPAC RULESsystematic nomenclature
“eye-you-pac”
colloquially:
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It is a system where every compound (even isomers)has a unique name.
If the rules are followed, everyone gets the same namefor a given compound.
Once given the name, anyone can draw the structureof the compound.
STRUCTURE NAME
WORKSBOTHDIRECTIONS
FEATURES OF THE IUPAC SYSTEMFEATURES OF THE IUPAC SYSTEM
IUPAC
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1.2
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IUPAC IUPAC METHOD METHOD
1. Find the longest continuous chain of carbon atoms and name it using the linear alkane names.
2. Number the chain starting from the end nearest a branch.
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IUPAC IUPAC METHOD METHOD
3. Give each substituent a name based on the number of carbon atoms it has.
4. Give each substituent a locant number determined by its location on the chain.
5. Assemble the name.
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RULE 1. FIND THE LONGEST CONTINUOUS RULE 1. FIND THE LONGEST CONTINUOUS CHAIN OF CARBON ATOMS AND CHAIN OF CARBON ATOMS AND NAME ITNAME IT
C-C-C-C-C-C-C-C-CC-C-C-C-C-C-C-C-C
C
C-C
C-C-CC-C-C
C-CC-C
CC
-C-C-C-C-CC- C-C-C-C-C-CC-C-C-C-C-C
C-CC-C
C-C-C-
C
it won’t always bethe horizontal one as shown here
all possibilites must be examined try these also ……..
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66 88
NONANE
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C-C-C-C-C-C-C-C-CC-C-C-C-C-C-C-C-C
C
C-C
RULE 2. Number the chain starting from RULE 2. Number the chain starting from the end nearest a branchthe end nearest a branch
1 2 3 4 5 6 7 8 9
nonane
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C-C-C-C-C-C-C-C-CC-C-C-C-C-C-C-C-C
C
C-Cnonane
substituent
substituent
Groups attached to the main chain are calledsubstituents.
1 2 3 4 5 6 7 8 9
RULE 3. Give each substituent a name based on the number of carbon atoms it has.
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methylethylpropylbutylpentylhexylheptyloctylnonyldecyl
(substituents)
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C-C-C-C-C-C-C-C-CC-C-C-C-C-C-C-C-C
C
C-Cnonane
ethyl
methyl
1 2 3 4 5 6 7 8 9
RULE 3. Give each substituent a name based on the number of carbon atoms it has.
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C-C-C-C-C-C-C-C-CC-C-C-C-C-C-C-C-C
C
C-Cnonane
ethyl
methyl
1 2 3 4 5 6 7 8 9
Rule 4. Give each substituent a locant number determined by its location on the chain.
2-
4-
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LOCANT SUBSTITUENT MAIN CHAIN STEM
ENDING
name of thesubstituent
indicates thenumber ofcarbon atomsin the chain
indicatesthe typeof compoundindicates
position of thesubstituenton the chain
number wordword
suffix
RULE 5. Assemble the name.
“ane”
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PUNCTUATION RULESPUNCTUATION RULES
1. Numbers are separated from words by hyphens
2. Numbers are separated from numbers by commas.
4. All words are joined - no breaks
example coming shortly
2-methyl…….
……methylnonane
2,3- ……..
3.Substituents are named in alphabeticalorder ……4-ethyl-2-methyl….
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C-C-C-C-C-C-C-C-CC-C-C-C-C-C-C-C-C
C
C-Cnonane
4-ethyl
2-methyl
1 2 3 4 5 6 7 8 9
4-ethyl-2-methylnonane
ASSEMBLING A NAMEASSEMBLING A NAME
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CH3 CH2 CH CH3
CH3
2. number from end nearest a branch
1. find longest chain and name
ORGANIC NOMENCLATUREORGANIC NOMENCLATURE
4 3 2 1 butane
methyl
2-methylbutane
2-
3. name substituents
4. locant number
5. assemble name
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CH3 CH2 CH CH3
CH2 CH3
1 2 3
4 5
Name this compound
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CH3 CH2 CH CH2 CH2 CH3
CH2 CH2 CH3
Name this compound
4 3 2 1
5 6 7
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Use multipliers if there areUse multipliers if there are MORE THAN MORE THAN ONEONE of the same substituentof the same substituent
DI-TRI-TETRA-PENTA-HEXA-HEPTA-OCTA-NONA-DECA-
These are ignoredwhen alphabetizing
2345678910
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CH3 CH2 C CH2 CH2 CH3
CH3
CH3
Every substituent must get a number
1 2 3 4 5 6
How would you name this one?