organic chemistry organic chemistry is the study of carbon containing compounds derived from living...
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Organic Chemistry
Organic chemistry is the study of carbon containing compounds derived from
living organisms.
Organic Compounds• Contain C bonded to other elements,
commonly H, O, N, S, and halogens
• Carbon – Can form many different compounds due to its
hybrid orbitals– Has intermediate electonegativity, so its most
likely to form molecular compounds (Recall: molecular compounds have diverse properties)
– Can make single, double, and triple bonds– Can form isomers (same molecular formula but
different arrangement of atoms)
Isomers
• Structural Isomers have the same molecular formula but the atoms are bonded together in a different sequence
• Stereoisomers are molecules with the same molecular formula, a same sequence of atoms but they have different 3D orientations
Stereoisomers
• Diastereomers form around a double bond and each carbon atom involved in the bond must have different types of atoms bonded to it
• Enantiomers are mirror images of each other
Types of Hydrocarbons• Saturated: Contain the maximum number of
hydrogens, single bonds between all carbons
• Unsaturated: Contain 1+ double or triple bonds
• Aliphatic Carbons are arranged in chains
• Cyclic: Carbons are arranged in rings
• Aromatic: Contain a benzene ring
Types of Hydrocarbons
Types of Hydrocarbons
Name Definition General Formula
Alkane Hydrocarbon with only single bonds between
carbon atoms. CnH2n+2
Alkene Hydrocarbon with at
least one double bond. CnH2n
Alkyne Hydrocarbon with at least one triple bond.
CnH2n-2
• Homologous series
• This is a series of compounds which all contain the same functional group, and have similar chemical properties.
• ALKANES ALKENES ALCOHOLS
• CH4 CH2 =CH2 CH3OH
• CH3-CH3 CH2 =CH –CH3 CH3CH2OH
• Each has a general formula:
• ALKANES: CnH2n+2
• The members of the series differ by the number of CH2 units.
• CH3-CH3, CH3-CH2-CH3, CH3-CH2-CH2-CH3
• Graduation in physical properties: eg: boiling points.
• CH4 (GAS), C8H18 (LIQUID), C30H62 (SOLID)
Rules for Naming Alkanes Rules for Naming Alkanes (Nomenclature)(Nomenclature)
For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon
CH3
CH3
CH3
12 3
4
44 carbon chain = butane carbon chain = butane
Naming Alkanes
Based off the number of C atoms in the longest chain
1. Count the number of C’s in the longest chain
2. Determine the appropriate root
3. Add the suffix “ane”
Hydrocarbon Root Names# of Carbons Root Name
1 meth-
2 eth-
3 prop-
4 but-
5 pent-
6 hex-
7 hept-
8 oct-
9 non-
10 dec-
Examples
• Butane
• Heptane
Naming Branched Alkanes
Based off the number of C atoms in the longest chain
1. Count the number of C’s in the longest chain
2. Determine the appropriate root
3. Use the numbered C’s to give the branches a position number add “yl” suffix
4. Add the suffix “ane”
Naming Branched Alkanes
Important Rules:1. Start numbering from the end that will give you
the lowest number of branches
2. If there is more than one type of branch, name the branches in alphabetical order
3. If there is more than two of the same type of branch, give the branch a position number and prefixes “di”, “tri” “tetra” etc.
4. Put commas between numbers and hyphens between numbers and letters
Rules for Naming Alkanes Rules for Naming Alkanes (Nomenclature)(Nomenclature)
When alkane groups appear as substituents, theyare named by dropping the -ane and adding -yl.
CH3
CH3
CH3
—CH3 Methyl
—CH2CH3 Ethyl
—CH2CH2CH3 Propyl—CH2CH2CH2CH3 Butyl
Methyl
Rules for Naming Alkanes Rules for Naming Alkanes (Nomenclature)(Nomenclature)
The positions of substituent groups are specifiedby numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching.
CH3
CH3
CH3
Methyl
12 3
4
Rules for Naming Alkanes Rules for Naming Alkanes (Nomenclature)(Nomenclature)
The location and name of each substituent arefollowed by the root alkane name. The substituentsare listed in alphabetical order (irrespective of anyprefix), and the prefixes di-, tri-, etc. are used toindicate multiple identical substituents.
CH3
CH3
CH3
Methyl
12 3
4 Name:2-methylbutane
Nomenclature PracticeNomenclature Practice
CH3 CH3
CH3
CH3
Cl
Name this compound
Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon
152 43
9
6
87
9 carbons = nonane
Nomenclature PracticeNomenclature PracticeName this compound
CH3 CH3
CH3
CH3
Cl
152 43
9
6
87
9 carbons = nonane
Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl.
CH3 = methyl
chlorine = chloro
Nomenclature PracticeNomenclature PracticeName this compound
CH3 CH3
CH3
CH3
Cl
152 43
9
6
87
9 carbons = nonane
CH3 = methyl
chlorine = chloro
Step #3: The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching.
1 9 NOT 9 1
Nomenclature PracticeNomenclature PracticeName this compound
CH3 CH3
CH3
CH3
Cl
152 43
9
6
87
9 carbons = nonane
CH3 = methyl
chlorine = chloro
Step #4: The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (irrespective of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents.
2-chloro-3,6-dimethylnonane
Cyclic AlkanesCyclic AlkanesCyclopropane, C3H6
Remember, explicit hydrogens are left out
Cyclobutane, C4H8
Cyclopentane, C5H10
Cyclohexane, C6H12
Cycloheptane, C7H14
Practice
• P. 11-16 #1, 2
Structural ShorthandStructural Shorthand
H
HH
H
HH
H
H
HH
Explicit hydrogens (those required to complete carbon’s valence) are usually left off of drawings of hydrocarbons
CH3
CH3
Line intersections represent carbon atoms
C1 C1C2 C2
C3 C3C4 C4
Different Methods of Displaying Compounds
• Molecular Formula
• Condensed Structural Formula
• Expanded Molecular Formula
• Structural Formula
• Line Formula
Naming Alkenes & Alkynes1. Count the number of C’s in the longest chain
containing the double/triple bond.• This is the parent chain, determine the root• Number the parent chain so that the double/triple bond has
the lowest possible position number
2. Identify the position numbers of branches• Same rules as before
3. Write the branches in alphabetical order4. Write the root, including a prefix that identifies the
position of the double/triple bond• Add the prefix “cyclo” if its cyclic
5. Add the suffix “ene” or “yne”
Naming Alkenes & Alkynes
Naming Aromatics1. Same rules2. If benzene is the parent chain “benzene” suffix3. If benzene is a branch group “phenyl”
Practice
• P. 16-22 #3-7, 8abc
• Naming Alkenes/Alkynes Worksheet
• Isomer Challenge Worksheet
• Naming Hydrocarbons Worksheet