Polynuclear aromatic hydrocarbons(PAH).pptx

Introduction and classification of Polynuclear aromatic Hydrocarbons, Preparation, Properties and uses of Naphthalene, Phenanthrene and Anthracene

1. POLYNUCLEAR HYDROCARBONS Presented by Ms. V. Pushpalatha M. Pharm Assistant Professor Dept. of Pharmaceutical Chemistry School of Pharmacy Sri Balaji Vidyapeeth University.

2. INTRODUCTION Polynuclear hydrocarbons are compounds which contain two or more aromatic rings. Also known as Polycyclic aromatic hydrocarbons. Polynuclear hydrocarbons are non polar and lipophilic in nature E.g. Naphthalene Diphenylmethane

3. Classification of Polynuclear aromatic Hydrocarbons

4. N aphthalene: The simple and most important fused ring system is naphthalene. Molecular formula – C 10 H 8 It is the largest single constituent of coal-tar. Erlenmeyer (1866) proposed the symmetrical formula for naphthalene and Graebe (1869) proved that it contains two benzene rings fused together in the ortho position. 1 2 3 4 5 6 7 8

5. Resonance structures of Naphthalene

6. Synthesis of Naphthalene I. Haworth synthesis: 3- Benzoyl propanoic acid

7. Tetralone

8. II. Synthesis of naphthalene from 4 phenylbut-1 ene

9. Physical properties: Naphthalene is a colorless solid which forms shining flaked crystals. The Molecular weight of Naphthalene is 128.18 g/mol. It is insoluble in water and soluble in organic solvents. It is very volatile and slowly sublimates at room temperature. Its melting point is 80.2℃ and boiling point is 217.9 ℃ It has an aromatic odour.

10. Chemical Properties

11. Uses of Naphthalene: It is used for the commercial production of Phthalic anhydride. It is used for making Insecticide. Used as a mouth repellant. Used for the manufacture of dyes and synthetic resins

12. References: Organic chemistry By Morison and Boyd, Page number : 967 – 982. Organic chemistry, Volume I, The Fundamental Principles by I.L Finar, Page Number : 697 – 722.

13. Thank You …