ORGANIC CHEMISTRY

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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?