CH2210 Aldehydes and Ketones

Alcohols Phenols Ethers Thiols Dissulfides Amines

-O- -S- -N-

OC

Alkanes Alkenes Alkynes Aromatics

Aldehydes Ketones Acids Esters Anhydrides Amides

OC-N

OC-O

Hydrocarbons

All Classes of Organic Compounds

Functionalized Hydrocarbons

Halides

F,Cl,Br O,S,N

OC

C O:

:

! bond

Structure of the Carbonyl Group

The carbonyl group is constructed in the same manner as the carbon-carbon double

bond, from an sp2 hybridized carbon atom and an sp2 hybridized oxygen atom.

4 electrons

C O:

:π bond

! bond

:

Structure of the Carbonyl Group

The carbonyl group is constructed in the same manner as the carbon-carbon double

bond, from an sp2 hybridized carbon atom and an sp2 hybridized oxygen atom.

.

.

Structure of the Carbonyl Group

C O

The angles between the three bonds to carbon

involved are approximately 120º.

Families Containing the Carbonyl Group

O

CZY

Family Y Zaldehyde H or C H

ketone C Ccarboxylic acid H or C -O-H

ester H or C -O-Camide H or C -N

Common Aldehydes and Ketones

CH2OFormaldehyde

Names for Simple Aldehydes and Ketones

CO

H H

CO

CH3 H

CO

CH3CH2 H

CO

CH3CH2CH2 H

CO

CH3 CH3

Compound Common name

Systematic name

formaldehyde methanal

acetaldehyde ethanal

propionaldehyde propanal

butyraldehyde butanal

acetone (dimethyl ketone) propanone

CO H

Benzaldehyde

Another Common Aldehyde

Names for More Complex Compounds

CO

CH2CH2CH HCl CH3

CH3CH2CCHCHCH3CH3

Br

O

4-chloro-2-methylbutanal

3-methyl-2-butanone 4-bromo-5-methyl-3-hexanone(isopropyl methyl ketone)

CO

CH3 CHCH3

CH3

CO

CH3 CHCH3

CH31

234

2

1 3

4

31 2

4

5 6

Additional Nomenclature Examples

CH2CH2

CH2C

O

CH3O

CH3

CH O

NO2

5-phenyl-2-pentanone 2-methylcyclopentanone

3-nitrobenzaldehyde (meta-nitrobenzaldehyde)

1

2

13

4

5

1

2

Physical Properties of Aldehydes and KetonesSummary of Important “Secondary Forces”

Which Contribute to boiling Points

Seco

ndar

y A

ttra

ctiv

e Fo

rces

London

Dipole-dipole

H-bonding

Increased Boiling Point

Hydrocarbons

Aldehydes and Ketones

Alcohols

Amines

240

200

160

120

80

40

-

-

-

-

-

-

Boili

ng P

oint

Physical Properties of Aldehydes and Ketones

I I I I I 40 80 120 160 200 Molecular Mass

Alcoho

ls

Alde

hyde

sAlkan

es

Physical Properties of Aldehydes and Ketones Water Solubility

CO

H H

CO

CH3 H

CO

CH3CH2 H

CO

CH3CH2CH2 H

CH3CH2CH2CH2CO

H

Compound Boiling Point (ºC) Water solubility (g/100 mL H2O)

-21 very soluble

21 very soluble

49 16

76 7

103 1

Physical Properties of Aldehydes

Physical Properties of Ketones

H3CC

CH3

O

CCH3

O

CH3CH2

CCH3

O

CH3CH2CH2

CCH3

O

CH3CH2CH2CH2

CCH3

O

CH3CH2CH2CH2CH2

Compound Boiling Point (ºC) Water solubility (g/100 mL H2O)

56 very soluble

80 26

102 6

127 -

151 -