LATE ABASAHEB KAKADE ART’S & SCIENCE COLLEGE , BODHEGAON

1. LATE ABASAHEB KAKADE ART’S & SCIENCE COLLEGE , BODHEGAON • Topic :- Nomenclature of Alkane, Alkene and Alkyne. • Presented By :- Assit.Prof.Nalawade R.B

2. First Ten Alkanes Alkane = CnH2n+2

3. Structural Shorthand Explicit hydrogens (those required to complete carbon’s valence) are usually left off of drawings of hydrocarbons C1 C2 C3 C4 C1 C3 C4 C2 Line intersections represent carbon atoms

4. Structural Isomers Isomers are molecules with the same chemical formula, but different organization of atoms (different bonding) n-Pentane, C5H12 Isopentane, C5H12 Neopentane, C5H12

5. Newman Projections Butane, C4H10

6. Cyclic Alkanes Cyclopropane, C3H6 Cyclobutane, C4H8 Cyclopentane, C5H10 Cyclohexane, C6H12 Cycloheptane, C7H14 Remember, explicit hydrogens are left out

7. Rules for Naming Alkanes (Nomenclature) For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon 1 2 3 4 4 carbon chain = butane

8. Rules for Naming Alkanes (Nomenclature) When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl. —CH3 Methyl —CH2CH3 Ethyl —CH2CH2CH3 Propyl —CH2CH2CH2CH3 Butyl Methyl

9. Rules for Naming Alkanes (Nomenclature) The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching. 1 2 3 4 Methyl

10. Rules for Naming Alkanes (Nomenclature) The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (irrespective of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents. 1 2 3 4 Name: 2-methylbutane Methyl

11. Nomenclature Practice Name this compound Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon 1 9 carbons = nonane 2 4 3 5 6 7 8 9

12. Nomenclature Practice Name this compound 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl.

13. Nomenclature Practice Name this compound Step #3: The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching. 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 1 9 NOT 9 1

14. Nomenclature Practice Name this compound Step #4: The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (irrespective of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents. 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 2-chloro-3,6-dimethylnonane

15. Alkenes Contain Carbon-CarbonDouble bonds 1  bond Ethene 1  bond

16. Alkynes Contain Carbon-CarbonTriple Bonds 1  bond Ethyne 1  bond 1  bond

17. Reactions of Alkenes and Alkynes Hydrogenation Propene Propane Halogenation 1-Pentene 1-2-dibromopentene Polymerization Small molecules are joined together to form a large molecule Polyethylene

18. Aromatic Hydrocarbons Cyclic unsaturated hydrocarbons with delocalized electrons The simplest aromatic hydrocarbon is benzene (C6H6) OR…

19. Geometric Isomerism in Aromatics ortho (o-) = two adjacent substituents o-dichlorobenzene meta (m-) = one carbon between substituents m-dichlorobenzene para (p-) = two carbons between substituents p-dichlorobenzene

21. THANK YOU