Overheads Chem 122

Organic Chemistry:

Organic Chemistry- That branch of

chemistry which centres on carbon and its

compounds.

Greek Prefixes:

mono

1

hexa

6

di

2

hepta

7

tri

3

octa

8

tetra

4

nona

9

penta

5

deca

10

Alkanes:

Alkanes: A hydrocarbon(compound

containing only carbon and hydrogen) in

which all carbon-carbon bonds are single

bonds.

n

Compound

Name

1 CH4 methane

2

CH3CH3

ethane

3

CH3CH2CH3

propane

4

CH3CH2 CH2CH3

n-butane

5

CH3(CH2)3CH3

n-pentane

6

CH3(CH2)4CH3

n-hexane

7

CH3(CH2)5CH3

n-heptane

8

CH3(CH2)6CH3

n-octane

9

CH3(CH2)7CH3

n-nonane

10

CH3(CH2)8CH3

n-decane

Drawing Organic Structures:

Consider n-butane: C4H10.

Drawing Organic Structures:

Consider n-butane: C4H10.

also written as

or

CH3-(CH2)2-CH3

Line Notation:

The end of each line represents a carbon atom

and the appropriate number of hydrogens.

Isomers:

Isomers- Compounds with the same

molecular formula but different arrangement

of atoms.

C C HC

HH

C

HH

H

H

H H H

C C H

H

C

CH

H

H

H H

H

H H

n-butane

Isobutaneor methylpropane

C5H12 has 3 isomers.




C30H62 has 4 BILLION isomers.

Isomers cont...:

Naming Alkanes: Remove a H from CH4(methane) to get a methyl

group

C

H

H

H

methyl C C

HH

H

H

H

ethyl

C C

H

C

HH

H

H

H H

n-propyl

C C

HH

C

H

H

isopropyl

H H

H

tert-butylC C

H

C

H

H H H

H

CH

H

H

Naming Alkanes cont…:

Naming:

prefix - parent - suffix

Identify the longest chain of C atoms.

Identify alkyl and/or side groups and

location.

Ex:

methylpropane

Ex:2

dimethylpropane

Ex:3

methylbutane

Ex:4

3-ethyl-2,2-dimethylpentane

1 2 3 4 5 1 3 5

2 4

Ex:5

3,3,4-trimethylhexane

3 4 5 6

2

1

3 4 6

5

2

1

Cycloalkanes:

Ring structures that contain only C-C

single bonds.

C

C

C

H

H

H

H

H H

cyclopropane

C

C C

CH

H H

H

H

H H

H

cyclobutane

General Formula CnH2n

Alkenes:

Alkenes are hydrocarbons which have a

carbon-carbon double bond somewhere in the

structure.

Alkenes have the general formula CnH2n

where n = 1, 2, 3, …

Name derived from the corresponding

alkane, except the ending is changed from

"ane" to “ene."

H H

CC

HH

H H

CC

HH

HH

ethane ethene

Naming Alkenes:

Alkenes cont…

For alkenes containing more than 4 carbon

atoms, the position of the double bond must

be indicated. Ex:

CH2=CHCH2CH3 1-butene

CH3CH=CHCH3 2-butene

5-methyl-2-hexene

In naming alkenes the largest chain is

numbered to give the lowest number to the

double bond.

Ex:

Alkenes cont…

6 4 2

5 3 1

Cis-trans Isomers:

Alkenes also exhibit geometric

isomerization. Due to restricted motion of

double bond. Not found in alkanes.

Consider ethane. Free rotation about C-C

single bond.

For ethane, C=C double bond results in

restricted motion about double bond.

H3C CH3

CC

HH

H CH3

CC

HH3C

cis-2-buteneB.P. = 1ºC

B.P. = 2.5ºCtrans-2-butene

Restricted motion in 2-butene results in two

stereoisomers.

Alkenes cont…

Alkenes may contain cis/trans stereoisomers.

Ex: cis-2-pentene

trans-2-pentene

HC CH

CH2

CH2H2C

H2C Replace "ane" with "ene."

Written as:

Cycloalkenes:

Alkynes:

Hydrocarbons that contain atleast one

carbon-carbon triple bond. When naming,

the ending "ane" of the corresponding alkane

is replaced with the ending "yne.“

HCCH ethyne. Also known as

acetylene.

Position of the triple bond must be indicated.

HCCCH2CH3 1-butyne

CH3CCCH3 2-butyne

Aromatic Hydrocarbons:

C

C

C

C

C

C

H

H

H

H

H

H

C

C

C

C

C

C

H

H

H

H

H

H

Benzene ring may berepresented as follows.

Model of Benzene:

Rotated

90

Degrees

H2C CH3

ethylbenzene

CH3

Phenyl group methylbenzeneor

toluene

Derivatives of Benzene:

Substituted Benzene:

Ex: dimethyl substituted benzene.

Use ortho(o), meta(m), and para(p) for

disubstituted benzenes. CH3 CH3 CH3

CH3

CH3

CH3

2-xylene

o-xylene

3-xylene

m-xylene

4-xylene

p-xylene

These are groups of atoms which give

hydrocarbons characteristic chemical and

physical properties.

Functional Groups:

Examples:

-OH: Alcohols

-NH2: Amines

-COOH: Carboxylic Acids

Some Benzene Compounds: CH3

toluene

NH2

aniline

OH

hydroxybenzeneor

phenol

CH3

m-chlorotoluene

Cl

NH2

o-chloroaniline

Cl

Alcohols:

Hydrocarbons that contain a -OH group.

Alcohols are named by taking the name of the

parent alkane and replacing the ending "ane"

to "anol."

Numbers are used to indicate the position of

the substituents, lowest number assigned to

the carbon containing the -OH group.

Alcohols cont…:

H C

H

H

C HC

HH

H

C

HH

H

H C

H

H

C OHC

HH

H

C

HH

H

primary alcohol1-butanol

n-butane

1-butanol

Alcohols cont…

CH3 CH CH

OH

CH3

CH3

secondary alcohol

3-methyl-2-butanol

CH3 C CH2

OH

CH3

CH3

2-methyl-2-butanoltertiary alcohol

Alcohols cont…

Ethers: Ethers have the general structure R-O-R.

R can be an alkyl or aromatic group.

CH3OCH

3

dimethyl ether

CH3 OCH2CH3

ethyl methyl ether

CH3 CH2OCH2CH2CH3

ethyl propyl ether

Ethers cont:

Ethers cont…:

O diphenyl ether

Aldehydes:

Contain the carbonyl group.

C

O

R: alkyl or aromatic group.

R C

O

H aldehyde

Naming Aldehydes:

H C

O

H

To name aldehydes, take the name of the

parent alkane and replace the ending "e"

with "al."

methanal

or

formaldehyde

ethanal

or

acetaldehyde

CH3 C

O

H

Aldehydes cont…

For larger aldehydes, #'s are used to indicate

position with C=O carbon given the lowest

number of one.

NOTE: Do not have to indicate position of

aldehyde carbon.

C C

O

H C C

H

C

H

H

H

H H

H

H H

3-methylbutanal

Ketones:

In a ketone, the chain is numbered to give the

C=O carbon the lowest number. Replace the

"e" of the parent alkane with "one."

R C

O

R ketone

R: alkyl or aromatic group.

Ketones cont…:

C C H

H

C

HH

H

H

H H

propane

C C H

H

C

OH

H

H H

propanone or acetone

propanone or acetone

(fingernail polish remover)

butanone

Ex:

5-methyl-3-hexanone

Carboxylic Acids:

Carboxylic acids contain the -COOH group.

C

O

OH

Named by dropping the "e" of the parent

alkane and replacing it with "oic acid." The

carbon on the carboxyl group is numbered

one.

Carboxylic Acids cont…:

C

O

OH

C C H

H

C

HH

H

H

H H

C C

HH

H

H

H

propane

propanoic acid

Ex:

3-methylbutanoic acid

Carboxylic Acids cont…

CO OH

benzoic acid

C

CH3

O OH

p-methylbenzoic acid

Esters:

General structure

R1 and R2 can be aromatic and/or alkyl

groups.

R C

O

OR1 2

H C

H

H

C HC

HO

H

C

H

H

ethyl ethanoate

O

Amines:

Amines are derivatives of ammonia.

R: alkyl, aromatic, or hydrogen.

N R

R

R..

NH3 ammonia

CH3CH

2NH

2 ethylamine

(CH3CH2)2NH diethylamine

(CH3CH

2)3N triethylamine

Overheads Chem 122

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