Organic Chemistry
Simple Organic Families
Organic Nomenclature
Organic Molecules
• Organic chemistry is the chemistry of
carbon compounds.
• Carbon has the ability to form long
chains.
• Without this property, large
biomolecules such as proteins, lipids,
carbohydrates, and nucleic acids could
not form.
• Carbon is the only element capable of
forming stable chains of atoms bonded
through single-double-triple bonds.
Structure of Carbon Compounds
• There are three hybridization states and geometries
found in organic compounds:
– sp3 tetrahedral
– sp2 trigonal planar
– sp linear
HYDROCARBON FAMILIES
• Divided into four groups based on the kinds
of carbon-carbon bonds present
#1. Alkanes
#2. Alkenes
#3. Alkynes
#4. Aromatics
Alkanes
• Alkanes contain only single bonds.
• They are also known as saturated hydrocarbons.
– They are “saturated” with hydrogens, only contain single
bonds.
Common
Alkanes
Writing Formulas for Alkanes
• Lewis structures of alkanes to the left below.
• They are also called structural formulas.
• They are often not convenient to attempt to
write so condensed formulas are typically used.
Properties of Alkanes
• The only force is the London dispersion force.
• The boiling point increases with the length of the chain.
Structure of Alkanes
• Carbons in alkanes are sp3 hybrids.
• They have a tetrahedral geometry
and 109.5 bond angles.
Structure of Alkanes
• There are only -bonds present in
alkanes.
• There is free rotation about the C—
C bonds.
What is an Isomer?
ISOMERS
STRAIGHT
ISOMERS
STRAIGHT
P. 1009
Isomers have
the same
molecular
formulas, but
the atoms are
bonded in a
different order.
Common Naming Schemes
-n
-iso
-n
-iso
-neo
AFTER THIS – CRAZY TOWN!
• Common Names
listed in 1st column.
• “ n “ indicates an
isomer of the normal
structure
• When a CH3 group
branches, the isomer
prefix –iso
• When another CH3
group branches, the
isomer prefix -neo
Organic Prefixes based on Carbon Chains
Organic Nomenclature
• There are three parts to a compound name:
– Base: This tells how many carbons are in the longest continuous
chain.
– Suffix: This tells what type of compound it is.
– Prefix: This tells what groups are attached to the chain.
Naming Simple Alkanes
Watch this link to learn to name simple alkanes!
Let’s try some!
How to Name a Compound
If there is more than
one type of substituent
in the molecule, list
them alphabetically.
GOT IT??? YEAH RIGHT!
WATCH THIS!
Cycloalkanes
• Carbon can also form ringed structures.
• Five- and six-membered rings are most stable.
– They can take on conformations in which their bond angles are
very close to the tetrahedral angle.
– Smaller rings are quite strained.
Reactions of Alkanes
• Alkanes are rather unreactive due to the presence
of only C—C and C—H -bonds.
• Therefore, they make great nonpolar solvents.
• Make great Combustion fuel!