1. Organic Chemistry Introduction Functional Groups Names and Structures
Alkanes
Cycloalkanes
Alkenes
Alkynes
Alcohols

2. Introduction
Organic chemistry is the study of carbon-containing compounds
The field of organic chemistry is very important for a wide variety of reasons.
A huge number of carbon-containing compounds are known.
Most of the advances in the pharmaceutical industry are based on a knowledge of organic chemistry.
Life as we know it is based on organic chemistry.

3. Introduction
Most organic compounds have a “skeleton” that is composed of C-C bonds.
The C-C bonds may be single bonds, double bonds, or triple bonds.
Carbon forms a total of 4 bonds.
The “skeleton” of an organic compound has H’s attached to it.
other “heteroatoms” like O, halogens, N, S, and P may be present as well

4. Introduction propane methane acetylene acetone
Some familiar organic compounds:
propane
methane
acetylene
acetone

5. Introduction Acetic acid “ether” aspirin Ethyl alcohol
Some familiar organic compounds:
Acetic acid
“ether”
aspirin
Ethyl alcohol

6. Introduction
Organic compounds are commonly classified and named based on the type of functional group present.
An atom or group of atoms that influences the way the molecule reacts, behaves, or functions
The center of reactivity in an organic compound

7. Functional Groups
On your exam, you will be responsible for recognizing and naming the various common functional groups that are found in organic compounds:
Use Table 25.4 and the following slides to help you study

8. Functional Groups Class of Compound Functional Group Alkane None
Cycloalkane
Alkyl halide
Alkene
Alkyne
Alcohol
Ether

9. Functional Groups Class of Compound Functional Group Aldehyde Ketone
Carboxylic Acid
Ester

10. Functional Groups Class of Compound Functional Group Amine Amide
Nitrile
Aromatic ring

11. Alkanes Contain C-C single bonds no functional group
Tetrahedral electron domain geometry
sp3 hybridized carbons
Free rotation around single bonds
propane

12. Cycloalkanes
Contain C – C with at least 3 of the carbons arranged in a cyclic (ring) structure
No functional group
Tetrahedral ed geometry
sp3 hybrid orbitals

13. Alkyl Halides Contain C-halogen bond F, Cl, Br, or I
Alkyl halides are generally (but not always) polar molecules.

14. Alkenes Contain C=C (carbon-carbon double bonds)
1 sigma bond & 1 pi bond
Trigonal planar geometry
sp2 hybridized carbons
Which atoms must be coplanar in an alkene?
1-propene

15. Alkenes
The C=C present in an alkene is composed of 1 sigma (s) bond and 1 pi (p) bond.
Double bonds are rigid and cannot rotate freely.
Rotation would cause loss of overlap of the p orbitals, destroying the p bond.
ethylene

16. Alkynes Contain C C (carbon-carbon triple bonds)
1 sigma bond
2 pi bonds
Linear electron domain geometry
sp hybridized carbons
Which atoms must be co-linear in an alkyne?

17. Aromatic Ring
Planar ring system with alternating single and double bonds
does not react like an alkene
Trigonal planar
sp2 hybridized carbons
Benzene ring is a very common aromatic ring.
benzene
pyridine

18. Functional Groups Alkanes are often called saturated hydrocarbons
Organic compounds composed of carbon and hydrogen that contain the largest possible number of hydrogen atoms per carbon atom.
Alkenes, alkynes, and aromatic hydrocarbons are called unsaturated hydrocarbons
Organic compounds composed of carbon and hydrogen that contain less hydrogen than an alkane having the same number of carbon atoms

19. Alcohols Contain C-O-H bond hydroxyl group
Alcohols form hydrogen bonds between molecules.
How does hydrogen bonding affect boiling point???
Amphoteric

20. Ethers Contain C-O-C bond tetrahedral e.d. geometry why?
bent molecular geo.

21. Amines Contain C-N-R R’ R and R’ can be H or C
Primary and secondary amines form hydrogen bonds.
Common organic bases
lone pair of e- on N
primary
secondary
tertiary

22. Aldehydes Contain (-CHO) Carbonyl (C=O) trigonal planar geometry
always on the 1st or last carbon in a chain
trigonal planar geometry
sp2 hybrid orbitals

23. Ketones Contain Trigonal planar e.d. geo. sp2 hybridized C O C-C-C
Carbonyl attached to middle of chain
Trigonal planar e.d. geo.
sp2 hybridized C

24. Carboxylic Acids Contain carboxyl group Form hydrogen bonds
trigonal planar
sp2 hybridized carbon

25. Esters
Contain
trigonal planar
sp2 hybridized

26. Amides Contain C=O is trigonal planar & sp2 hybridized
where R and R’ = H or C
C=O is trigonal planar & sp2 hybridized

27. Nitriles
Contain
Linear
sp hybridized C

28. Functional Groups
Example: Identify the functional groups present in the following compounds.
thyroxine
testosterone

29. Functional Groups
Example: Identify the functional groups in the following compounds.
Lisinopril
Vanillin

30. Depicting Structures of Organic Compounds
Organic compounds can be depicted using a variety of formulas:
Empirical formula
Molecular formula
Lewis structure
Full structural formula
Three dimensional drawings
Condensed structural formula
Line angle drawings

31. Depicting Structures of Organic Compounds
Ethyl acetate is an organic molecule with:
empirical formula = C2H4O
molecular formula = C4H8O2

32. Depicting Structures of Organic Compounds
Ethyl acetate is an organic molecule with:
Lewis structure:
depicts all covalent bonds using a straight line and shows all nonbonding pairs of electrons
Full structural formula:
a Lewis structure without the nonbonding electrons

33. Depicting Structures of Organic Compounds
Ethyl acetate is an organic molecule with:
3-d drawing:
Condensed structural formula
Line angle drawing

34. Names and Structures of Alkanes
Some of the simplest alkanes:
You must know these!!!

35. Names and Structures of Alkanes
Some of the simplest alkanes:
You must know these!!!

36. Names and Structures of Alkanes
The previous alkanes are also called straight-chain hydrocarbons:
all of the carbon atoms are joined in a continuous chain
Alkanes containing 4 or more carbons can also form branched-chain hydrocarbons (branched hydrocarbons)
some of the carbon atoms form a “branch” or side-chain off of the main chain

37. Names and Structures of Alkanes
An example of a straight chain hydrocarbon:
C5H12 CH3CH2CH2CH2CH3 pentane
Examples of a branched hydrocarbon:
C5H12 CH3CHCH2CH3 CH3
CH3 CH3CCH3
CH3
2-methylbutane
2,2-dimethylpropane

38. Names and Structures of Alkanes
The three structures shown previously for C5H12 are structural isomers:
compounds with the same molecular formula but different bonding arrangements
Structural isomers are unique compounds and generally have different properties:
different melting points
different boiling points
often different chemical reactivity

39. Names and Structures of Alkanes
Organic compounds can be named either using common names or IUPAC names.
You must be able to name alkanes, cycloalkanes, alkyl halides, alkenes, alkynes, and alcohols with 10 or fewer carbons in the main chain (or ring) using the IUPAC naming system.

40. Names and Structures of Alkanes
Alkane Nomenclature:
Find the longest continuous chain of carbon atoms and use the name of the alkane with the same number of carbons for the base name of the compound:
The longest chain is not always written in a straight line.
Base name:
heptane

41. Names and Structures of Alkanes
Number the carbon atoms in the longest chain beginning with the end of the chain closest to a substituent
groups attached to the main chain that have taken the place of a hydrogen atom on the main chain
A substituent

42. Names and Structures of Alkanes
Name and give the location of each substituent
Common substituents:
Halo group
a halogen atom
“Halo” groups are named using “halo”:
Cl chloro
Br bromo
I iodo
F fluoro

43. Names and Structures of Alkanes
Common substituents:
alkyl group
A substituent that is formed by removing an H atom from an alkane
the alkyl group attaches to the main chain at the carbon that has lost its H

44. Names and Structures of Alkanes
Alkyl groups are named by replacing the “ane” ending of the parent alkane with the “yl” ending.
Alkyl groups to know:

45. Names and Structures of Alkanes
Alkyl groups to know (cont):

46. Names and Structures of Alkanes
Methyl group
3-methylheptane
Note: Separate numbers from letters using a hyphen. Separate groups of numbers using commas.

47. Names and Structures of Alkanes
Alkane Nomenclature:
When two or more substituents are present, list them in alphabetical order:
Butyl vs. ethyl vs. methyl vs. propyl
When more than one of the same substituent is present (i.e. two methyl groups), use prefixes to indicate the number. Give the location of each as well.
Di = two
Tri = three
Tetra = four
Penta = five
Note: Ignore these prefixes when alphabetizing.

48. Names and Structures of Alkanes
Additional rules:
If each end of the longest chain has a substituent the same distance from the end, start with the end nearer to the second substituent.
correct
incorrect
3-chloro-2,5-dimethylhexane

49. Names and Structures of Alkanes
Example: Name the following compounds:

50. Names and Structures of Alkanes
You must also be able to draw the structure of an alkane when given the IUPAC name.
Identify the main chain and draw the carbons in it
Identify the substituents (type and #) and attach them to the appropriate carbon atoms on the main chain.
Be sure to connect the proper atoms when drawing bonds.
Add hydrogen atoms to the carbons to make a total of 4 bonds to each carbon

51. Names and Structures of Alkanes
Example: Draw the condensed structure for the following compounds. Draw a line angle drawing for each.
2,2-dimethylbutane
2-bromo-3-ethylhexane

52. Names and Structures of Alkanes
Example: Draw the condensed structure for the following compound. Draw a line angle drawing for it.
2-methyl-4-propyloctane

53. Names and Structures of Cycloalkanes
Cycloalkanes are named by:
Use cyclo as a prefix with the name of the alkane with the same number of carbons present in the ring as the base name.
Identify the substituents present using name and position number:
No position number is used if only one substituent is present.
For 2 or more substituents, number the ring to give the lowest possible numbers for the substituted carbons.

54. Names and Structures of Cycloalkanes
isopropylcyclohexane
1,1-dibromo-3-methylcyclopentane

55. Names and Structures of Cycloalkanes
Example: Name the following compounds.

56. Names and Structures of Cycloalkanes
Example: Draw the following compounds.
1-chloro-3-ethylcyclohexane
bromocyclobutane