1. Organic
Chemistry

2. What Is Organic Chemistry?
Organic chemistry is a branch of chemistry that focuses on compounds that contain carbon.
Except CO, CO2, carbonates, and carbides.
Even though organic compounds only contain a few elements, the unique ways carbon atoms can attach together to form molecules leads to millions of different organic compounds.

3. The Chemistry of Life
Life as we know it is because of organic chemistry.
Organic molecules can be very large and complex; this allows the complex functions of the cells to occur.
When chemists tried to classify compounds in the 1700’s, they found vast differences between the compounds found in living and nonliving things.

4. Classifying Pure Substances, the Modern Way
Some
Yes No
Yes No

5. What’s Special About Organic Compounds?
Organic compounds tend to be molecular.
Mainly composed of just six nonmetallic elements.
C, H, O, N, S, and P.
Compounds found in all three states.
Solids, liquids, and gases.
Solids tend to have low melting points.
Solubility in water varies depending on which of the other elements are attached to C and how many there are.
CH3OH is miscible with water; C10H21OH is insoluble.

6. What’s So Special About Carbon?
Carbon atoms can do some unique things that other atoms cannot.
Carbon can bond to as many as four other atoms.
Bonds to carbon are very strong and nonreactive.
Carbon atoms can attach together in long chains.
Carbon atoms can attach together to form rings.
Carbon atoms can form single, double, or triple bonds.

7. Hydrocarbons Compounds that contain only carbon and hydrogen
Two classes: Aliphatic and aromatic 7

8. The Petroleum Feedstock
Most hydrocarbons come from petroleum
Composed mostly of alkanes and aromatic hydrocarbons

10. Purification via fractional distillation

11. Hydrocarbons Hydrocarbons contain only C and H.
Two classes of hydrocarbons: saturated or unsaturated.
Insoluble in water.
No polar bonds to attract water molecules.
May be chains or rings.
Ring molecules have less H than chain so that the ends can join.
Chains may be straight or branched.
Rings may be aliphatic or aromatic.

12. Uses of Hydrocarbons Number of C atoms State Major uses 1–4 gas
heating and cooking fuel
5–7
liquids,
(low boiling)
solvents, gasoline
6–18
liquids
gasoline
12–24
jet fuel; camp stove fuel
18–50
(high boiling)
diesel fuel, lubricants, heating oil
50+
solids
petroleum jelly, paraffin wax
1–4
Gas
heating and cooking fuel
5–7
Liquids
(low boiling)
solvents, gasoline
6–18
Liquids
gasoline
12–24
Liquids
jet fuel, camp stove fuel
18–50
Liquids
(high boiling)
diesel fuel, lubricants, heating oil
50+
Solids
petroleum jelly, paraffin wax

13. Saturated Hydrocarbons
A saturated hydrocarbon has all C—C single bonds.
It is saturated with hydrogens.
Saturated hydrocarbons are called alkanes.
Chain alkanes have the general formula CnH2n+2.
Chains may be straight or branched.
Ring alkanes have two fewer Hs per ring than the corresponding chain isomer.

14. Unsaturated Hydrocarbons
Unsaturated hydrocarbons have one or more C=C double bonds, CC triple bonds, or aromatic rings.
Unsaturated hydrocarbons that contain C=C are called alkenes.
The general formula of a monounsaturated chain alkene is CnH2n.
Unsaturated hydrocarbons that contain CC are called alkynes.
The general formula of a monounsaturated chain alkyne is CnH2n-2.

15. Some Unsaturated Hydrocarbons15

16. Aromatic Hydrocarbons
Aromatic hydrocarbons contain a ring structure that seems to have C=C, but doesn’t behave that way.
The most prevalent example is benzene.

17. Hydrocarbons

18. Types of Hydrocarbons
Alkynes
alkanes
alkenes 18

19. Formulas
Molecular formulas just tell you what kinds of atoms are in the molecule, but they don’t tell you how they are attached.
Structural formulas show you the attachment pattern in the molecule.
Models not only show you the attachment pattern, but give you an idea about the shape of the molecule.

20. Carbon Skeleton Formulas
A.k.a. line-angle formulas.
Used very often with ring structures.
Each angle, and its beginning and end represent a C atom.
H omitted on C,
but included on functional groups.
Multiple bonds indicated.
Double line is double bond; triple line is triple bond. 20

21. Tro's Introductory Chemistry, Chapter 18

22. 22

23. Write the Structural and Condensed Formula for the n-Alkane C8H18.
Connect the C atoms in a row.
Carbon skeleton.
Add H to complete four bonds on each C.
Middle C gets 2 Hs.
End C gets 3 Hs.
The condensed formula has the H attached to each C written directly after it.
CH3CH2CH2CH2CH2CH2CH2CH3

24. Practice—Write a Complete Structural Formula for C7H16, Continued.24

25. Alkanes Also know as paraffins. Aliphatic, saturated.
General formula CnH2n+2 for chains.
Very unreactive.
CH3 groups at ends of chains; CH2 groups in the middle.
Chains may be straight or branched.
n-Alkane = straight chain.

26. Structural Isomers
Isomers are molecules with the same molecular formula, but different arrangements of the atoms.
Different chemical and physical properties.
Structural isomers are isomers in which the atoms are attached differently.
Different bonding pattern.
Structural isomers have different physical properties.
Structural isomers may give different products in a reaction, though they undergo the same types of reactions.

27. Structural Isomers of C4H10
Butane, BP = 0 °C
Isobutane, BP = -12 °C

28. Possible Structural Isomers

29. Example—Write the Structural Formula and Carbon Skeleton Formula for C6H14.
Start by connecting the carbons in a line.
Determine the C skeleton of the other isomers. 29

30. Example—Write the Structural Formula and Carbon Skeleton Formula for C6H14, Continued.
Fill in the Hs to give each C four bonds.

31. Physical Properties of Hydrocarbons
Solubility:
Tend to be insoluble in water
Good preservative for reactive metals
Density:
Tend to have lower densities than water
0.6 g/mL – 0.8 g/mL

32. Alkanes—Physical Properties
Nonpolar molecules, intermolecular attractions are London dispersion forces due to momentary dipoles only.
Both boiling points and melting points generally increase as the size of the molecule increases.
Insoluble in water, commonly used as nonpolar solvents.
Less dense than water, density increases with size.

33. Physical Properties of n–Alkanes

34. Naming Alkanes Find the longest, continuous carbon chain.
Number the chain from the end closest to a branch.
If first branches equal distance, use the next in.
Name branches as alkyl groups.
Locate each branch by preceding its name with the carbon number on the chain.
List branches alphabetically.
Do not count n-, sec-, t-, but count iso.
Use prefix if more than one of the same group is present.
di-, tri-, tetra-, penta-, hexa-.
Do not count in alphabetizing.

35. Branches—Alkyl Groups3 - , M E T Y L 2 P R O ( ) I S

36. More Alkyl Groups C H 3 ( ) 2 - , I S O B U T Y L s e c n
tert-

37. Examples of Naming Alkanes
H H H H H
H C C C C C H
H CH3 H H H
2-methylpentane
H CH3 H H H H
H C C C C C C H
H CH3 CH H H H
CH3 CH3
3-isopropyl-2,2-dimethylhexane

38. Example—Name the Alkane.
1. Find the longest, continuous C chain and use it to determine the base name.
Since the longest chain has 5 Cs,
the base name is pentane.

39. Example—Name the Alkane
2. Identify the substituent branches.
There are two substituents.
Both are one C chains called methyl.

40. Example—Name the Alkane
3. Number the chain from the end closest to a substituent branch.
If first substituents equidistant from end, go to next substituent in.
Then assign numbers to each substituent based
on the number of the main chain C to which its
attached.
Both substituents are equidistant from the end.

41. Example—Name the Alkane
4. Write the name in the following order:
Substituent number of first alphabetical substituent followed by dash.
Substituent name of first alphabetical substituent followed by dash.
If it’s the last substituent listed, no dash.
Use prefixes to indicate multiple identical substituents.
Repeat for other substituents alphabetically.
Name of main chain.
2,4 –
dimethyl
pentane

42. Practice—Name the Following:

43. Practice—Name the Following, Continued:
3-ethyl-2-methylpentane

44. Practice—Draw the Structural Formula of 4-isopropyl-2-methylheptane.

45. Practice—Draw the Structural Formula of 4-isopropyl-2-methylheptane, Continued.

46. Alkenes Also known as olefins. Aliphatic, unsaturated.
C=C double bonds.
Formula for one double bond = CnH2n.
Subtract two Hs from alkane for each double bond.
Trigonal shape around C.
Flat.
Much more reactive than alkanes.
Polyunsaturated = many double bonds. 47

47. n–1–Alkenes

48. Alkenes
Ethene = ethylene
Propene

49. Physical Properties of Alkenes

50. Alkynes Also known as acetylenes. Aliphatic, unsaturated.
CºC triple bond.
Formula for one triple bond = CnH2n-2.
Subtract four Hs from alkane for each triple bond.
Linear shape.
More reactive than alkenes. 51

51. n–1–Alkynes

52. Alkynes
Ethyne = acetylene
Propyne

53. Physical Properties of Alkynes

54. Naming Alkenes and Alkynes
Find longest chain containing multiple bond.
Alkene takes precedence over alkyne.
Change suffix on main name from -ane to -ene for base name of alkene, or to –yne for the base name of the alkyne.
Number chain from end closest to multiple bond.
Number in front of main name indicates first carbon of multiple bond.

55. Examples of Naming Alkenes
H H H
H C C C C C H
H CH3 H H H
2-methyl-1-pentene
H CH H H
H C C C C C C H
H CH3 CH H H H
CH3 CH3
3-isopropyl-2,2-dimethyl-3-hexene

56. Examples of Naming Alkynes
H H H
H C C C C C H
CH3 H H
3-methyl-1-pentyne
H CH3 H H
H C C C C C C H
H CH3 CH H
CH3 CH3
4-isopropyl-5,5-dimethyl-2-hexyne

57. Reactions of Hydrocarbons
All hydrocarbons undergo combustion.
Combustion is always exothermic.
About 90% of U.S. energy generated by combustion.
2 CH3CH2CH2CH3(g) + 13 O2(g) → 8 CO2(g) + 10 H2O(g)
CH3CH=CHCH3(g) + 6 O2(g) → 4 CO2(g) + 4 H2O(g)
2 CH3CCCH3(g) + 11 O2(g) → 8 CO2(g) + 6 H2O(g)

58. Chemical Energy Burning hydrocarbons releases heat and light energy.
Combustion.
Alkane + oxygen ® carbon dioxide + water.
Larger alkane, more heat released.

59. Addition Reactions

60. Practice—Predict the Products.

61. Practice—Predict the Products, Continued.

62. Aromatics  Benzene Reactions are generally substitutions for H.
Resonance hybrid.
Does not react like alkenes.
Reactions are generally substitutions for H. 

63. Resonance Hybrid
The true structure of benzene is a resonance hybrid of two structures.

64. Naming Monosubstituted Benzene Derivatives
(Name of substituent) benzene.
Halogen substituent = change ending to “o.”
fluorobenzene
propylbenzene
Or name of a common derivative.

65. Naming Benzene as a Substituent
When the benzene ring is not the base name, it is called a phenyl group.
4-phenyl-1-hexene

66. Naming Disubstituted Benzene Derivatives
Number the ring starting at attachment for first substituent, then move toward second.
Order substituents alphabetically.
Use “di-” if both substituents are the same. 1 2 3
1-bromo-3-fluorobenzene 1 2
1,2-dimethylbenzene

67. Practice—Name the Following:

68. Practice—Name the Following, Continued:
1-chloro-4-fluorobenzene
1,3-dibromobenzene
or meta-dibromobenzene
or m-dibromobenzene

69. Functional Groups
Other organic compounds are hydrocarbons in which functional groups have been substituted for hydrogens.
A functional group is a group of atoms that show a characteristic influence on the properties of the molecule.
Generally, the reactions that a compound will perform are determined by what functional groups it has.
Since the kind of hydrocarbon chain is irrelevant to the reactions, it may be indicated by the general symbol R.
CH3—OH
R group
Functional group

70. Functional Groups, Continued

71. Alcohols R—OH. Ethanol = CH3CH2OH. Isopropyl alcohol = (CH3)2CHOH.
Grain alcohol = fermentation of sugars.
Alcoholic beverages.
Proof number = 2x percentage of alcohol.
Gasohol.
Isopropyl alcohol = (CH3)2CHOH.
2-propanol.
Rubbing alcohol.
Poisonous.
Methanol = CH3OH.
Wood alcohol = thermolysis of wood.
Paint solvent.

72. Naming Alcohols Find the main chain that contains OH.
Unless C=O present.
Number main chain from end closest to OH.
Give base name -ol ending and place number of C on chain where OH attached in front.
Name as hydroxy group if other higher precedence group present. 1 2 3 4 5 6
4-ethyl-4-methyl-3-hex-5-enol

73. Practice—Draw a Structural Formula for 3-ethyl-2,4-dimethyl-2-pent-4-enol.74

74. Ethers R–O–R. Ether = diethyl ether = CH3CH2OCH2CH3.
Anesthetic.
To name ethers, name each alkyl group attached to the O, then add the word ether to the end.

75. Aldehydes and Ketones Contain the carbonyl group.
Aldehydes = at least 1 side H.
Ketones = both sides R groups.
Many aldehydes and ketones have pleasant tastes and aromas.
Some are pheromones.
Formaldehyde = H2C=O.
Pungent gas.
Formalin = a preservative.
Wood smoke, carcinogenic.
Acetone = CH3C(=O)CH3.
Nail-polish remover.
Formaldehyde
Acetone

76. Aldehyde Odors and Flavors
Butanal = butter.
Vanillin = vanilla.
Benzaldehyde = almonds.
Cinnamaldehyde = cinnamon.

77. Ketone Odors and Flavors
Acetophenone = pistachio.
Carvone = spearmint.
Ionone = raspberries.
Muscone = musk.

78. Naming Aldehydes and Ketone
Make part of main chain.
Number from end closest to carbonyl.
Precedence over OH group.
For aldehyde, change ending to -al.
Always position 1, no number necessary.
For ketone, change ending to -one.
Indicate position on chain with number in front of base name.
4-hydroxybutanal
4-hydroxy-3-hex-1-enone

79. Carboxylic Acids RCOOH. Sour tasting. Weak acids. Citric acid.
Found in citrus fruit.
Ethanoic acid = acetic acid.
Vinegar.
Methanoic acid = formic acid.
Insect bites and stings.

80. Carboxylic Acids Made by the oxidation of aldehydes and alcohols.
OH on the end of the chain.
Always on main chain.
Has highest precedence.
C of group always C1.
Position not indicated in name.
Change ending to -oic acid.

81. Naming Acids Main chain always contains COOH group.
C of COOH group always Cl.
Position not indicated in name.
Give base name -oic acid ending.
3-hydroxy-3-methylpentanoic acid 82

82. Esters R–COO–R. Sweet odor.
Made by reacting carboxylic acid with an alcohol.
RaCOOH + RbOH  RaCOORb + H2O
Name alkyl group from alcohol, then acid name with -ate ending.
Precedence over carbonyls, but not carboxylic acid.
Number from end with ester group.
Aspirin

83. Naming Esters Main chain always contains COOR group.
Unless acid group also present.
C of COOR group on C1.
Position not indicated in name.
Start by naming R group as alkyl group.
No position number.
Always listed first, even if other groups on chain.
Change ending on base name to -oate.
methyl-4-isopropylbenzoate 84

84. Naming Esters

85. Amines N containing organic molecules. Very bad smelling.
Form when proteins decompose.
Organic bases.
Name alkyl groups attached to the N, then add -amine to the end.
Putrescine
Ethylamine
Ethylmethylamine
Cadaverine

86. Identify the Functional Groups in Each.
CH3CH2COOCH3.
(CH3CH2)2NH.
CH3CHCHCH2CHO. O H C O 3

87. Identify the Functional Groups in Each, Continued.
CH3CH2COOCH3.
(CH3CH2)2NH.
CH3CHCHCH2CHO.
Ester
Ester O
Ketone
and
ether
Amine
Acid,
aromatic
ring,
ether H C O 3
Double bond
and aldehyde