Organic Chemistry

1. Organic Chemistry CE 541

2. Aromatic Hydrocarbons They are hydrocarbons that include benzene and compounds containing aliphatic or aromatic groups attached to aromatic rings. Benzene is the simplest aromatic hydrocarbon (C6H6)

3. More recently, the following is used to represent the structure of Benzene

4. Nomenclature The monocyclic aromatic hydrocarbons are named as derivatives of the parent benzene. Trivial names of some of the compounds are still recognized by the IUPAC T oluene o-xylene m-xylene p-xylene (ortho-xylene) (meta-xylene) (para-xylene)

5. In the IUPAC system, aromatic compounds with one group attached to them are named by combining the name of the group with benzene. All these structures are named as Chlorobenzene, and all represent the same compound.

6. There are three different ISOMERIC compounds with two substituents on the ring. The positions of the substituents on these compounds are indicated as follows: ortho (or 1, 2 - ) meta (1, 3 - ) para (or 1, 4 - ) abbreviated o- abbreviated m- abbreviated p-

7. Using benzene or toluene as parent structure, the following examples illustrate the use of the system o-dichlorobenzene m-dichlorobenzene p-dichlorobenzene o-chlorotoluene m-chlorotoluene p-chlorotoluene

8. For compounds with three or more substituents on the ring, we must use numbers to indicate the position on the ring and apply the following rules: • The parent structure is benzene or toluene • For benzene, the group name written next to the word “benzene” becomes position number 1 on the ring and the ring is numbered in a direction that will give the lowest possible numbers to the substituents. • For toluene, the methyl group becomes position number 1 on the ring and the ring is numbered in a direction that will give the lowest possible numbers to the substituents. The number 1 position is assumed in both benzene and toluene derivatives, but is not indicated in the name. • All groups are placed in alphabetical order except the group in the number 1 position.

9. (a) Iodobenzene (b) m-dinitrobenzene (c) p-nitrobromobenzene (d) 4 – bromo – 2 - nitrotoluene Examples

10. (e) 2, 5 – dibromo – 3 nitrotoluene

11. Hydrocarbons 1. Benzene Series • Benzene C6H6 • Toluene C6H5 + CH3 • Xylene C6H4 (CH3)2 • Ethylbenzene C6H5 + C2H5 They : • Are used extensively as solvents • Are insoluble in water (relatively) • Are common constituents of petroleum products • Cause cancers to human

12. Styrene is a benzene derivative used in the production of polystyrene products Styrene

13. 2. Polyring Hydrocarbons (a) Naphthalene (C10 H8) (b) Anthracene (C14 H10)

14. (c) Phenanthrene (C14H10)

15. Chlorinated Aromatic Hydrocarbon (1) Chlorinated Benzenes They are benzene with one or more of the hydrogen are replaced by chlorine (2) Polychlorinated Biphenyls (PCBs) They are chlorinated benzenes with the following general structure: • X can be H or Cl • There are 209 possible PCBs • Stable compounds (some can be biodegraded) • Used widely as coolants in transformers, solvents, and hydraulic fluids • Bio-concentrate

16. Organic Halides Alkyl halides Alkyl group attached to a halogen atom such as F, Cl, Ba, I. General formula: R – X R = alkyl group X = halogen atom Aryl halides Halogen atom attached to an aromatic ring. General formula: Ar – X Ar = Aromatic ring X = halogen atom Derivatives of the Hydrocarbons 1. Organic Halides Examples • DDT (dichlorodiphenyltrichloroethane) • Chlorofluorocarbons (CFC, CF2Cl2, CFCl3)

17. Nomenclature

20. Nomenclature

22. Examples

24. Classifications of Alcohols

27. Common Alcohols

28. Chemical Reactions of Alcohols

34. Nomenclature

36. Examples

40. Nomenclature

41. Examples

45. Nomenclature Trivial names of few aldehydes are accepted by IUPAC system. These names are derived from the corresponding carboxylic acids by replacing the –ic of the acid by -aldehyde

48. Examples