1. The basis for organic chemistry
Hydrocarbons
The basis for organic chemistry

2. 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)

3. Types of Hydrocarbons
Saturated: Contain the maximum number of hydrogens, single bonds between all carbons
Unsaturated: Contain 1+ double or triple bonds

4. Types of Hydrocarbons Aliphathic Carbons are arranged in chains
Cyclic: Carbons are arranged in rings
Aromatic: Contain a benzene ring

5. Types of Hydrocarbons

6. Naming Alkanes Based off the number of C atoms in the longest chain
Count the number of C’s in the longest chain
Determine the appropriate root
Add the suffix “ane”

7. 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-

8. Structural Shorthand
Explicit hydrogens (those required to complete carbon’s valence) are usually left off of drawings of hydrocarbons C1 C2 C3 C4 C1 C2 C3 C4
Line intersections represent carbon atoms

9. Cyclic Alkanes Cyclopropane, C3H6 Cyclobutane, C4H8
Cyclopentane, C5H10
Cyclohexane, C6H12
Cycloheptane, C7H14
Remember, explicit hydrogens are left out

10. Rules for Naming Alkanes (Nomenclature)
For a branched hydrocarbon, the longest continuous chain
of carbon atoms gives the root name for the hydrocarbon 1 2 3 4
4 carbon chain = butane

11. Naming Branched Alkanes
Based off the number of C atoms in the longest chain
Count the number of C’s in the longest chain
Determine the appropriate root
Use the numbered C’s to give the branches a position number add “yl” suffix
Add the suffix “ane”

12. Naming Branched Alkanes
Important Rules:
Start numbering from the end that will give you the lowest number of branches
If there is more than one type of branch, name the branches in alphabetical order
If there is more than two of the same type of branch, give the branch a position number and prefixes “di”, “tri” “tetra” etc.
Put commas between numbers and hyphens between numbers and letters

13. Rules for Naming Alkanes (Nomenclature)
When alkane groups appear as substituents, they
are named by dropping the -ane and adding -yl.
—CH3 Methyl
—CH2CH3 Ethyl
—CH2CH2CH3 Propyl
—CH2CH2CH2CH3 Butyl
Methyl

14. Rules for Naming Alkanes (Nomenclature)
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 2 3 4
Methyl

15. Rules for Naming Alkanes (Nomenclature)
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. 1 2 3 4
Name:
2-methylbutane
Methyl

16. Nomenclature Practice
Name this compound 1
9 carbons = nonane 2 4 3 5 6 7 8 9
Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon

17. Nomenclature Practice
Name this compound
9 carbons = nonane 1 2 4 3 5 6
CH3 = methyl 7
chlorine = chloro 8 9
Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl.

18. Nomenclature Practice
Name this compound
9 carbons = nonane 1 2 4 3 5 6
CH3 = methyl 7
chlorine = chloro 8 9 1 9
NOT 9 1
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.

19. Nomenclature Practice
Name this compound
9 carbons = nonane 1 2 4 3 5 6
CH3 = methyl 7
chlorine = chloro 8 9
2-chloro-3,6-dimethylnonane
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.

20. Naming Alkenes & Alkynes
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
Identify the position numbers of branches
Same rules as before
Write the branches in alphabetical order
Write the root, including a prefix that identifies the position of the double/triple bond
Add the prefix “cyclo” if its cyclic
Add the suffix “ene” or “yne”

21. Naming Alkenes & Alkynes

22. Naming Cyclic Hydrocarbons
1. Number the carbons in the ring, in either direction, so that the multiple bond is between the two lowest numbers, and the branches get the lowest possible position numbers.
2. Identify branches.. Prefixes are the same di, tri, prop etc. and are written alphabetically.
3. The root is –cyclo- plus the name for the number of carbon atoms in the ring.
4. The suffix is –ane for cycloalkanes –ene for cycloalkenes and –yne for cycloalkynes.

23. Naming Cyclic Hydrocarbons

24. Naming Aromatics Same rules
If benzene is the parent chain “benzene” suffix
If benzene is a branch group “phenyl”

25. Naming Aromatic Hydrocarbons

26. Properties of Hydrocarbons
Made up of mostly C and H
Relatively nonpolar
Low solubility in polar solvents (e.g. water)
Good solvents for other nonpolar molecules
Mostly london-dispersion forces (weak)
Low boiling and melting points

27. Reactivity of Hydrocarbons
Alkanes are generally less reactive than alkenes or alkynes
Aromatic compounds are more reactive than alkanes, but less reactive than alkenes and alkynes.
Alkanes < aromatics < alkenes < alkynes

28. Reactions of Hydrocarbons
Combustion:
Hydrocarbons burn readily in air to produce carbon dioxide and water.
Incomplete Combustion:
Produces carbon and poisonous carbon monoxide.
C3H8(g) O2(g) --> 3CO2(g) + H2O(g)
C3H8(g) + 7/2 O2(g) --> C(s) + CO(g) CO2(g) H2O(g)

29. Reactions of Alkanes
Single bonds between carbon atoms are difficult to break. (This is why alkanes are relatively unreactive)
Can undergo combustion reactions and substitution reactions

30. Reactions of Alkanes Substitution Reactions:
Hydrogen atoms may be substituted by a halogen.
The product is a halogenated alkane (alkyl halides)

31. Reactions of Alkenes and Alkynes
Addition Reactions:
Reactions in which a molecule is added to a double or triple bond.
No loss of hydrogen atoms from the hydrocarbon

32. Types of Addition reactions

33. Hydrohalogenation
Hydration

34. Markovnikov’s Rule “The rich get richer”
When a hydrogen halide is added to an alkene or alkyne, the hydrogen atom bonds to the carbon atom that already has more hydrogen atoms.
Carbon 1 has 2 H’s
Carbon 2 has 1 H

35. Benzene Ring Does not act as 3 single bonds and 3 double bonds
It’s 6 identical bonds of intermediate length
Due to hybridization (delocalized, shared electrons)

36. Reactions of Aromatic Hydrocarbons
Less reactive than alkenes and do not undergo addition reactions unless under conditions of extreme temperature or pressure
Do undergo substitution reactions (more reactive than alkanes)