Download PowerPoint - Name Hydrocarbons

Organic Chemistry
• Carbon is the basis of organic chemistry
• Carbon has the ability to make 4 covalent
bonds.
• Carbon can repeatedly make covalent bonds
to itself to make rings and chains.
• Carbon can make single, double or triple
bonds to itself and other elements.
• Aliphatic compounds are hydrocarbons
which form a chain which may be straight
or branched, not rings.
• When naming organic compounds, every
compound should have its own unique
name. The # of carbon atoms present must
be indicated. Each name has a prefix which
states the # of carbon atoms.
Alkanes
• Simplest hydrocarbons, they contain only
carbon to carbon bonds (single bonds).
• The suffix –ane is used to show an Alkane
(only single bonds).
To name Alkane Nomenclature
• 1. Find the longest continuous carbon chain
• 2. Use prefixes (table P) to indicate # of
carbon atomsi n longest chain.
• 3. Use suffix “ane” to indicate single bonds
Alkenes & Alkynes
• Hydrocarbons which contain one double
bond between carbon atoms.
• They use the suffix ene in naming
• Alkynes are hydrocarbons which contain
one triple bond
• They use the suffix yne in naming
Unsaturated hydrocarbons
• Since the molecule has a double or triple
bond, there are less H’s on the chain. His
looks like they are missing H’s, we classify
them as unsaturated.
• Alkanes are saturated hydrocarbons. They
have the max # of H’s on the chain – others
are not.
Isomer
• When molecules have the same formula but
different structre.
• Different substances, have different
properties from each other.
• To give each isomer a name you need to use
a # to indicate which C atom the double
bond starts (lowest possible number is given
to carbon closest to double bond)
C4H8
These
molecules are
different
because their
structures are
different
(double bond is
in different
places)
Numbering carbons
Q- draw pentene
A- Where’s the bond? H3C
5
1
We number C atoms
H
H
1-pentene
C
C
C
C
H
H
H
H
4
2
3
2
4
1
5
H
• Thus, naming compounds with multiple bonds
is more complex than previously indicated
• Only if 2+ possibilities exist, are #s needed
• Always give double bond the lowest number
• Q - Name these
H
C 2H 4
H 3C
C
2-butene
C
CH3
Ethene
H
H 3C
CH3 3-nonyne
Cyclic structures
H
H
H
H
C
C
C
H
• Cyclic structures are circular
C C
• Have “cyclo” in name
H
H
H
H
• Benzene is not a cyclic structure
• cyclopentane
H
CH2
H2C
CH2
Benzene Ring C6H6
• Contains 6 carbons and 3 double bonds
Branched Alkanes
• These are saturated hydrocarbons which
have carbon atoms which hang from the
main chain. They are not a straight chain.
• Functional Group- is a group of atoms
which hang off the main chain
• Methyl Group- only has a single carbon in
the branch ex. CH3
• Ethyl group has two carbons in a branch
• ex: CH3CH2
• Propyl group has 3 carbons branched
• Ex:CH3CH2CH2
• If there are more than one functional group
you must write prefix, di, tri, tetra
Naming side chains
CH3
CH33
H3C
• Names are made up
of: side chains, root
• 2,3-dimethylpentane
CH3
• Root is the longest possible HC chain
• Must contain multiple bonds if present
• Add -yl to get name of side chain H C
CH3
3
• Common side chains include:
CH
CH3- methyl
CH3CH2- ethyl
*
CH3CH2CH2- propyl
Naming side chains
CH2
ethyl
CH2 CH3
1
CH3 CH2 C
2
5
CH2 C
3
4
CH3
6
CH3
methyl
methyl
Rule 8,9: group similar branches
2-ethyl-4,4-dimethyl-1-hexene
Naming side chains
H3C
H 3C
CH2
H 2C
CH CH3
CH2
CH3
3-methylhexane
CH2 CH2 CH3
CH CH CH2 CH3
H3C
CH
CH3
4-ethyl-2,3-dimethylheptane
Naming side chains
Name the structures below
CH3
CH
H 3C
CH2
CH
CH3
H 2C
H3C
H3C
3-ethyl-2-methylpentane
CH3
CH3
3-ethyl-1,5,5trimethylcyclohexene
CH3
IUPAC Rules for Halocarbon
Nomenclature
• 1. Find and name the longest continuous carbon chain.
• 2. Identify and name groups attached to this chain. Using
the prefixes for each halogen.
• 3. Number the chain consecutively, starting at the end
nearest a substituent group.
• 4. Assemble the name, listing groups in alphabetical order.
• 6. The prefixes di, tri, tetra are used to designate several
groups of the same kind, are not considered when
alphabetizing.
• Cl- chloro, F- Fluoro, Br- Bromo
More practice
Br
4-bromo-7-methyl-2-nonene
Alcohols
• An Alcohol is a substance where one or
more carbons within a hydrocarbon are
replaced with a –OH
• -OH is called a hydroxyl group
• Only one –OH can be attached to one
carbon.
• CRT: R—OH
• Replace ending of name with -ol
Name this Alcohol
Ether
• An organic compound that contains an ether group
• Ether group- an oxygen atom connected to 2
hydrocarbon branches
• CRT: R-O-R
• IUPAC says: name each branch connected to O
independently from each other
• -change ending to –yl of each group than add ether
to the end of the name.
Name this Ether!
Aldehydes
• Compounds containing the functional group
called the carbonyl group.
• Carbonyl group is a carbon double bonded
to an oxygen at their the start or end of a
chain.
• CRT:
Drop the –e ending from the
hydrocarbon and change it to -al
• Name this Aldehyde!
Ketones
• Contain a carbonyl group within the middle
of a carbon chain.
• CRT:
• In order to name ketones, you drop the –e
ending from the hydrocarbon name and add
an –one.
• The location of the =O on the chain must be
indicated with a number.
Name that Ketone!
Practice- Name each:
Organic Acids
• Carboxylic acids contain a -COOH group at
the first (last) Carbon.
• Usually written R-COOH or R-CO2H
• Very weak acids that do not break up
completely in water (dissociate).
• IUPAC naming : replace final –e with
• –oic acid
Name this Organic Acid!
Esters
• Esters are derived from carboxylic acids.
• Any carboxylic acid contains –COOH
group.
• In an Ester, a hydrogen (not on the first
carbon) is replaced with a –COO
symbolized as R-COO-R
• Esters smell nice, frangrances of many flowers,
used in perfume, responsible for tastes of ripened
ruits, Beeswax.
• Esters look like 2 they are in 2 parts.
• First name the alkyl (R) group (part hanging off of
acid part)
• Than name the group which contains the double
bond (R-COO-R)
• For this group, replace the oic acid as used
previously with –oate.
Name that Ester!
Amines
• Think of Ammonia NH3
• In amines, the hydrogen atoms in the
ammonia are replaced one at a time by
hydrocarbon groups.
• There are different types of amines based on
how many hydrogen atoms are replaced.
• In primary amines, that means 1 hydrogen
has been replaced RNH2 where R is an
alkyl group
• In secondary amines, 2 hydrogens are
replaced.
• In tertiary amines, all of the hydrogens in an
ammonia molecule have been replaced.
How to name:
• 1. name each branch of the hydrocarbon
chain attached to the Nitrogen and end with
amine.
• 2. –NH2 is an amino group, so you can
name the hydrocarbon as usual but begin
the name with amino
• 3. Name the longest hydrocarbon chain and
replace the –e in –ane with amine.
What are the 3 different names of
this amine?
• 1. 2-Propyl Amine
• 2. 2- Amino Propane
• 3. 2-Propanamine
Amides
• Amides are derived from carboxylic acids
meaning the –COOH group
• In an amide the OH part of that group is
replaced by an –NH2 group
• R-CONH2
• IUPAC naming: replace the –e at the end
with an -amide
Example
Name this amide!
• What would
• Ethyl ethanamide
• Look like?