1. Organic Chemistry

2. Introduction
Organic chemistry is the study of carbon compounds (generally hydrocarbons).
Animals, plants, and other forms of life consist of organic compounds.
Nucleic acids, proteins, fats, carbohydrates, enzymes, vitamins, and hormones are all organic compounds.
Biochemistry was developed later as the study of the chemical compounds and reactions in living cells.
Intro

3. Organic Chemistry - Introduction
Scientists had originally thought that organic compounds contained a “vital force” due to their natural origin like milk obtained from animals, sugar from sugar cane are organic.
This was disproved by Friedrich Wöhler in 1828.
Wöhler was able to make urea, a carbon compound in human urine, in the laboratory from a mineral.
Organic chemistry is an enormous field.
Intro

4. Numbers and Types of Bonds Application of the octet rule indicates that these elements should bond as shown below:
Section 14.1

5. Identifying Valid & Incorrect Structural Formulas Example
Two structural formulas are shown above. Which on does not represent a real compound?
In structure (a) each H and halogen has one bond, each C has four bonds, and each O has two bonds.
This is a valid structure.
Section 14.1

6. Identifying Valid & Incorrect Structural Formulas An Example
As we examine (b), we note that each H has one bond, each C has four bonds, the N has three bonds, BUT the O has three bonds.
The O should only have two bonds.
Therefore (b) is not a valid structure.
Section 14.1

7. Hydrocarbons Hydrocarbons are the most simple organic compounds.
Hydrocarbons contain only carbon (C) and hydrogen. (H)
For classification purposes, all other organic compounds are considered derivatives of hydrocarbons.
Hydrocarbons can be divided into aromatic and aliphatic hydrocarbons.
Section 14.2

8. Aromatic Hydrocarbons
Aromatic hydrocarbons contain one or more benzene ring.
Benzene (C6H6) is the most important aromatic hydrocarbon.
It is a clear, colorless liquid with a distinct odor.
Section 14.2

9. Other Aromatic Hydrocarbons
Toluene is used in modeling glue. Naphthalene is use in mothballs, and Phenanthrene are used in the synthesis of dyes, explosives, and drugs.
Section 14.2

10. Aliphatic Hydrocarbons
Aliphatic hydrocarbons are hydrocarbons having no benzene rings.
Aliphatic hydrocarbons can be divided into four major divisions:
Alkanes
Cycloalkanes
Alkenes
Alkynes
Section 14.3

11. Classification of Hydrocarbons
Section 14.2

12. Alkanes Alkanes are hydrocarbons that contain only single bonds.
Alkanes are said to be saturated hydrocarbons
Because their hydrogen content is at a maximum.
Alkane general formula  CnH2n + 2
The names of alkanes all end in “-ane.”
Methane  butane are gases
Pentane  C17H36 are liquids
C18H38 and higher are solids
Section 14.3

13. Members of the Alkane Series All satisfy the general formula CnH2n + 2
Section 14.3

14. Models of Three Alkanes
Names, Structural Formulas, Condensed Structural Formulas, and Ball-and-Stick Models
Section 14.3

15. Methane – Tetrahedral Geometry
Ball-and-Stick & Space-Filling Models Carbon’s four single bonds form angles of 109.5o
Section 14.3

16. Alkane Products
Alkanes are also found in paints, plastics, drugs, detergents, insecticides, and cosmetics.
Only 6% of the petroleum consumed goes into making these products.
The remaining 94% of the petroleum is burned as one of the various energy-related products.
Although alkanes are highly combustible, they are otherwise not very reactive..
Section 14.3

17. Alkyl Group This group does not exist independently but occurs bonded to another atom or molecule.
Section 14.3

18. Organic Compound Nomenclature
Due to the large number, variety, and complexity of organic compounds, a consistent method of nomenclature has been developed.
Section 14.3

19. IUPAC System of Nomenclature Alkanes
Compound is named as a derivative of the longest continuous chain of C atoms.
Positions & names of the substituents added
If necessary, substituents named alphabetically
More than one of same type substituent – di, tri, tetra
The C atoms on the main chain are numbered by counting from the end of the chain nearest the substituents.
Each substituent must have a number.
Section 14.3

20. The longest continuous chain of C atoms is five
Example
The longest continuous chain of C atoms is five
Therefore this compound is a pentane derivative with an attached methyl group
Start numbering from end nearest the substituent
The methyl group is in the #2 position
The compound’s name is 2-methylpentane.
Section 14.3

21. Substituents in Organic Compounds
Section 14.3

22. Drawing a Structure from a Name
Number the C atoms from right to left.
Attach a methyl group (CH3--) to carbon number 2 and number 3.
Add necessary H atoms.
2,3-dimethylhexane
Section 14.3

23. Cycloalkanes
Members of the cycloalkane group possess rings of carbon atoms.
They have the general formula CnH2n.
Each carbon atom is bonded to a total of four carbon or hydrogen atoms.
The smallest possible ring consists of cyclopropane, C3H6.
Section 14.3

24. The First Four Cycloalkanes
Note that in the condensed structural formulas, there is a carbon atom at each corner and enough hydrogens are assumed to be attached to give a total of four single bonds.
Section 14.3

25. Alkenes
Members of the alkene group have a double bond between two carbon atoms.
One hydrogen atom has been removed from two adjacent carbon atoms, thereby allowing the two adjacent carbon atoms to form a double bond.
General formula is CnH2n
Begins with ethene (ethylene) C2H4
Section 14.3

26. Some Members of the Alkene Series
Section 14.3

27. Naming Alkenes
“-ane” suffix for the corresponding alkane is changed to “-ene” for alkenes.
A number preceding the name indicates the C atom on which the double bond starts.
The carbons are numbered such that the double bond has the lowest number.
For example, 1-butene and 2-butene
Section 14.3

28. Alkynes
Members of the alkyne group have a triple bond between two carbon atoms.
General formula is CnH2n-2 Begins with ethyne (acetylene) C2H2
Due to the triple carbon bond, each alkyne molecule can react with two molecules of hydrogen.
Section 14.3

29. Alkenes are very Reactive and are termed “unsaturated hydrocarbons”
Alkenes will characteristically react with hydrogen to form the corresponding alkane.
Section 14.3

30. Alkynes are Unsaturated Hydrocarbons
Due to the triple carbon bond, each alkyne molecule can react with two molecules of hydrogen.
Section 14.3

31. Groups with a Carbon–Oxygen Double Bond (Carbonyl Groups)
Aldehyde: one hydrogen bonded to C=O
Ketone: two C’s bonded to the C=O
Carboxylic acid: OH bonded to the C=O
Ester: C-O bonded to the C=O
Amide: C-N bonded to the C=O
Acid chloride: Cl bonded to the C=O

32. Alcohols
Alcohols are organic compounds containing the hydroxyl group, —OH, attached to an alkyl group.
General formula is R—OH
Their IUPAC (International Union of Pure and Applied Chemistry) names end in “-ol.”
The most simple alcohol is methanol.
Ethanol is used in alcoholic beverages, perfumes, dyes, and varnishes.
Section 14.4

33. Amines
Organic compounds that contain nitrogen and are basic (alkaline) are called amines.
General formula for an amine is R—NH2.
Section 14.4

34. Carboxylic Acids Carboxylic acids contain the carboxyl group . (–COOH)
They have the general formula RCOOH.
Section 14.4

35. Isomers
Compounds having same chemical formula but different structures are called isomers.
There are two classes of isomers
1. Constitutional or Structural Isomerism
Stereo Isomerism.

36. Chain Isomerism
Compounds having same molecular formula but different carbon chain or skeleton are called chain isomers and this phenomenon is called Chain isomerism.
Molecular Formula C5H12
Molecular Formula C4H10O

37. Functional group Isomers
Compounds having same molecular formula but different functional groups are called functional groups isomers.

38. Position isomerism
Compounds having same molecular formula but different position of Functional group or double bond or triple bond are called position isomers and this phenomenon is called Position isomerism.

39. Optical Isomerism
The compounds having the same molecular formulas, structural formulas, physical and chemical properties but differing in their action on plane polarized light are called optical isomer and phenomenon is called optical isomerism.
Optical activity
The property of a compound to rotate the plane polarized light in either direction is called optical activity. OR
The substance rotating the plane of polarized light to the left or right is called optical active and this property of rotating planner polarized light is called optical activity.

40. Dextro rotatory ( or d form)
Laevo Rotatory (or l form)
The molecule rotating the plane of polarized light to the left is called Laevo rotatory or l form.
Dextro rotatory ( or d form)
The molecule rotating the plane of polarized light to the right is called dextro rotatory or d form.

41. THE END