Aldehydes
SCH 4UI
Mr.Snyder
Culminating Project
Sherry Wong
Aly Kadar
Kasey Bourgon
Define:
Aldehydes
An organic compound characterized
by a terminal carbonyl functional
group
General Structure
Functional group
Terminal Carbonyl group
One
+
H atom
+
(C=O)
bonded to C
R (Either another H atom or an alkyl group [carbon chain])
∴ Carbonyl group always occurs at the end of a carbon chain
Functional Group: Another H atom
The H atom is attached to the C
in the carbonyl group
IUPAC: Methanal
Common name: Formaldehyde
Functional Group: Alkyl Group
•
Attached to the C in the carbonyl
group
o
Examples
1. Cyclohexanal
2. IUPAC: Ethanal
(Common Name: Acetaldehyde)
General Structure
Functional group
Carbonyl group (C=O)
+
One H atom bonded to C
+
R (Either another H atom or an alkyl group [carbon chain])
∴ Carbonyl group always occurs at the end
of a carbon chain
General Structure
Difference between ALDEHYDES & KETONES
Carbonyl Group
Ketones
Aldehydes
Nomenclature: A Change of Suffix
Ex: Methane -> Methanal (AKA:
Formaldehyde)
★ Carbonyl group always at the end of the
carbon chain
★ Replace the -ane at the end of the name
with an -al
○
aldehyde
Physical & Chemical Properties
Boiling Point: Lower than analogous alcohols
(ex. Ethanol - 78°C / Ethanal - 21°C)
H-Bonds:
Polarity:
N/A (because there is no OH [hydroxide] groups)
Strong polar group
(due to double C=O bond)
(electronegativity)
Solubility:
High
Everyday Life Uses
Smaller → Strong, unpleasant odours
HYDROGEN ATOM
Formaldehyde (aka. IUPAC name = Methanal)
•
•
•
•
Simplest aldehyde
Colourless gas @ room temperature
In (aq) solution = antiseptic and disinfectant
Used as a preservative
ONE CARBON
Acetaldehyde (aka. IUPAC name = Ethanal)
•
•
Colourless liquid
Synthesis of resins, dyes, and preservatives
Trimer
= 3 molecules joined together into a single large molecule
Formaldehyde
Fumigate rooms against pests
Acetaldehyde
Hypnotic drug
Everyday Life Uses
•
•
•
Larger → Flowery, pleasant odours
Ex. Cinnamaldehyde
Found in essential oils of plants
(ex. Frankincense egyptian and Rosalina Austrialian essential oils)
Used for fragrance in perfumes and aromatherapy products
o Aldehydes are refered to as aliphatic or "fatty" aldehydes
o Fatty aldehydes have a chain of 8-13 carbon atoms
(ex. Chanel No.5 Perfume)
Reactions
Kasey
Reaction Worksheet
Kasey
Bibliography
Kessel, H. v., Jenkins, F., Davies, L., Plumb, D., Giuseppe, M. D., & Lantz,
O. (2003). Nelson Chemistry 12 . Toronto: Kevin Martindale.
Aldehydes. (n.d.). perfume ingredient, fragrance and essential oils.
Retrieved November 25, 2013, from
http://www.fragrantica.com/notes/Aldehydes-165.html