Nomenclature of hydrocarbons.pptx

Hydrocarbons

1. Younas , M. (1994). A textbook of organic chemistry. Ilmi Kitab Khana , Urdu bazar, Lahore. 1 Nomenclature of Hydrocarbons (Alkane, Alkene, Alkyne & Aromatic Hydrocarbons)

2. Table of Contents Sr. No. Contents Slide No. 1 Classification of Hydrocarbons 1 2 Classification of Organic Compounds 2 3 Classification of Carbon Atoms 3 4 Nomenclature of Organic Compounds 7 5 IUPAC Nomenclature of Alkanes 11 6 IUPAC Nomenclature of Alkenes 25 7 IUPAC Nomenclature of Alkynes 31 8 IUPAC Nomenclature of Aromatic Hydrocarbons 37 2

3. 1 Depending upon the characteristic pattern of bonding between the carbon atoms, hydrocarbons are divided into two main classes: aliphatic and aromatic. Aliphatic Hydrocarbon Aromatic Hydrocarbon Aliphatic hydrocarbons include three major groups: alkanes, alkenes and alkynes. Aromatic hydrocarbons are cyclic compounds which contain characteristic benzene ring or its derivatives. Classification of Hydrocarbons Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

4. Classification of Organic Compounds 2 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

5. Classification of Carbon Atoms 4 types of Carbon atoms Primary Carbon Secondary Carbon Tertiary Carbon Quaternary Carbon 3 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

6. 4 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

7. A carbon atom attached to three other carbon atoms A carbon atom attached to four other carbon atoms 5 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

8. C H 3 C C H 3 C H 3 C C H 3 C H 2 C H 3 H s e c o n d a r y t e r t i a r y p r i m a r y q u a t e r n a r y 6 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

9. There as two system  of nomenclature of organic compounds Trivial system (ii) IUPAC System Nomenclature of Organic Compounds 7 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

10. Organic Nomenclature This method of nomenclature was used before 1892. In this system of nomenclature, the compounds were named on the basis of their history, such as source of origin etc. Common or Trivial System 8 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

11. A method known as the Geneva system was suggested in 1892 by the International Chemical Congress at Geneva for naming organic compounds. Later the International Union of Chemistry at Liege (Belgium) developed it into IUPAC system of nomenclature in 1930. In 1958 , the IUPAC system was modified by the International Union of Pure and Applied Chemistry (IUPAC) into the present day IUPAC system of nomenclature. IUPAC System Figure : Classification of IUPAC System 9 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

12. Examples of Common and IUPAC Naming System of Alkenes & Alkynes 10 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

13. IUPAC Rules for naming Alkanes Select the longest continuous chain of carbon atoms as the parent chain and name the hydrocarbon. Rule-1 The longest continuous chain has four carbon atoms, thus the compound is named as butane. 11 Younas, M. (1994). A textbook of organic chemistry. Ilmi Kitab Khana, Urdu bazar, Lahore.

14. Number the carbon atoms in the longest continuous chain in such a way as to give lowest possible number to carbons atoms carrying substituents. Rule-2 12 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

15. 13 Younas, M. (1994). A textbook of organic chemistry. Ilmi Kitab Khana, Urdu bazar, Lahore.

16. Name the substituent. Indicate its position by the number of the carbon atom to which it is attached. Rule-3 The attached group is located on carbon 2 of the chain, and it is a Methyl group. 14 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

17. Prefix the position number and name of the substituent onto the parent name . The whole name is written as one word . Note that the number and name of the substituent are separated by a hyphen. Rule-4 15 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

18. 16 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

19. If identical substituents are present more than once in the molecule, then use prefixes di- tri-tetra-,penta-, etc. Position of each substituent is indicated by a separate number. Rule-5 17 Younas, M. (1994). A textbook of organic chemistry. Ilmi Kitab Khana, Urdu bazar, Lahore.

20. When two or more different substituen ts are present, their names are arranged in alphabetic order and added to the name of the parent alkane, again as one word. Rule-6 18 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

21. Numbers are separated from each other by commas Numbers are separated from names by hyphens  Prefixes di-, tri-, are not taken into account in alphabetizing substituent names Points to be Remember 19 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

22. Structural Formulas from the IUPAC Names Step-by-step procedure to draw structural formulas from the IUPAC names. Consider the following IUPAC name: 3,3-Diethyl-5-methyldecane 20 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

23. Draw a decane skeleton and number it . Step-1 21 Younas, M. (1994). A textbook of organic chemistry. Ilmi Kitab Khana, Urdu bazar, Lahore.

24. Attach two ethyl groups at C-3 Step-2 22 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

25. Attach a methyl group at C-5 Step-3 23 Younas, M. (1994). A textbook of organic chemistry. Ilmi Kitab Khana, Urdu bazar, Lahore.

26. Supply hydrogen atoms so that each carbon atom has four bonds. Step-4 24 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

27. IUPAC Rules for naming Alkenes Select the longest continuous chain of carbon atoms containing the double bond , as the parent chain . Rule-1 25 Younas, M. (1994). A textbook of organic chemistry. Ilmi Kitab Khana, Urdu bazar, Lahore.

28. Name the longest chain. The name is obtained by replacing “ ane ” of alk ane with “ ene ” . Rule-2 26 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

29. Number the chain from the end closer to the double bond. Rule-3 27 Younas, M. (1994). A textbook of organic chemistry. Ilmi Kitab Khana, Urdu bazar, Lahore.

30. Indicate the position of the double bond by the number of the first (lowest numbered) carbon atom involved in the double bond. Rule-4 28 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

31. Alkyl groups and other substituent's are numbered , named and placed as prefixes in alphabetical order. Rule-5 29 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

32. If more than one double bonds are found then use the prefixes di, tri, tetra, for 2,3 and 4. Alkenes containing two double bonds are named as ALKADIENES. Rule-6 30 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

33. IUPAC Rules for naming Alkynes Select the longest continuous carbon chain containing at least one triple bond, as the parent chain. Rule-1 31 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

34. Name the longest chain. The name is obtained by replacing ane of alk ane with y ne . Rule-2 32 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

35. Number the chain from the end closer to the triple bond. Rule-3 33 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

36. Indicate the position of the triple bond by the number of the first (lowest numbered) carbon atom involved in the triple bond. Rule-4 34 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

37. Alkyl groups and other substituents are numbered, named and placed as prefixes in alphabetical order. Rule-5 35 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

38. If more than one triple are found then use the prefixes di,tri,tetra,for 2,3 and 4. Alkynes containing two triple bonds are named as ALKADYINE. Rule-6 36 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

39. According to  IUPAC nomenclature  of substituted aromatic compounds, the substituent name is placed as a prefix to the name of aromatic compounds. For example, a benzene ring attached to a one-nitro group is named as nitrobenzene. IUPAC Rules for naming Aromatic Hydrocarbons Rule 1 37 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

40. A number of the monosubstituted benzene derivatives have special names which represent the benzene ring together with its substituents. For example, 38 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

41. Rule 2 When more than one similar substituent group is present in the ring, they are labeled with the Greek numerical prefixes such as di, tri, tetra to denote the number of similar substituent groups attached to the ring. If two bromo- groups are attached to the adjacent carbon atoms of the benzene ring, it is named 1,2-dibromobenzene. 39 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

42. In the case of disubstituted aromatic compounds, sometimes terms like ortho (o), meta (m) and para (p) are also used as prefixes to indicate the relative positions 1,2-; 1,3- and 1,4- respectively. For example, 1,2 di-chloro-benzene can be named as o-di-chloro-benzene. Rule 3 40 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

43. When different substituted groups are attached to the aromatic compounds, the substituent of the base compound is assigned number one and then the direction of numbering is chosen such that the next substituent gets the lowest number. Substituents are named in alphabetical order. For example: when chloro and nitro groups are attached to the  benzene ring , we first locate the chloro group then nitro groups. Rule 4 41 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

44. The substituent names are listed in alphabetical order. The first substituent is given the lowest number. When a common name is used, the carbon atom that bears the group responsible for the name is given the number 1: Rule 5 42 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.

45. When an alkane with a functional group is attached to an aromatic compound, the aromatic compound is considered as a substituent, instead of a parent. For example: when a benzene ring is attached to an alkane with a functional group, it is considered as a substituent named phenyl, denoted by Ph-. Rule 6 43 Younas, M. (1994). A textbook of organic chemistry . Ilmi Kitab Khana, Urdu bazar, Lahore.