Chapter 22 Organic and Biological Molecules

Chapter 22 Organic Chemistry and Biochemistry  Organic Chemistry  The study of carbon-containing compounds and their properties. The vast majority of organic compounds contain chains or rings of carbon atoms.  Biochemistry  The study of the chemistry of living things. Copyright © Cengage Learning. All rights reserved 2

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 3 Hydrocarbons  Compounds composed of carbon and hydrogen.  Saturated: C—C bonds are all single bonds. alkanes [C n H 2n+2 ]

Section 22.1 Alkanes: Saturated Hydrocarbons Hydrocarbons  Unsaturated: contains carbon–carbon multiple bonds.

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 5 Isomerism in Alkanes  Structural isomerism – occurs when two molecules have the same atoms but different bonds.  Butane and all succeeding members of the alkanes exhibit structural isomerism.

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 6 Butane

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 7 Rules for Naming Alkanes 1.For alkanes beyond butane, add –ane to the Greek root for the number of carbons. CH 3 –CH 2 –CH 2 –CH 2 –CH 2 –CH 3 = hexane 2.Alkyl substituents: drop the –ane and add –yl. C 2 H 6 is ethane C 2 H 5 is ethyl

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 8 Rules for Naming Alkanes 3.Positions of substituent groups are specified by numbering the longest chain sequentially. The numbering is such that substituents are at lowest possible number along chain. CH 3 CH 3 –CH 2 –CH–CH 2 –CH 2 –CH methylhexane

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 9 Rules for Naming Alkanes 4.Location and name are followed by root alkane name. Substituents in alphabetical order and use di–, tri–, etc. CH 3 CH 3 CH 3 –CH 2 –CH–CH–CH 2 –CH ,4-dimethylhexane

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 10 First Ten Normal Alkanes

Section 22.1 Alkanes: Saturated Hydrocarbons The Most Common Alkyl Substituents and Their Names

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 12 Name each of the following: a) 2,2,4,5-tetramethylhexane b) 3,6-diethyl-3-methyloctane EXERCISE!

Section 22.1 Alkanes: Saturated Hydrocarbons Copyright © Cengage Learning. All rights reserved 13 Cyclic Alkanes  Carbon atoms can form rings containing only C—C single bonds.  General formula: C n H 2n C 6 H 12 C4H8C4H8 C3H6C3H6

Section 22.2 Alkenes and Alkynes Hydrocarbons  Alkenes: hydrocarbons that contain at least one carbon–carbon double bond. [C n H 2n ] CH 3 –CH=CH 2 propene  Alkynes: hydrocarbons containing at least one carbon– carbon triple bond. [C n H n ] CH 3 –CH 2 –CΞC–CH 3 2–pentyne

Section 22.2 Alkenes and Alkynes Rules for Naming Alkenes 1.Root hydrocarbon name ends in –ene. C 2 H 4 is ethene 2.With more than 3 carbons, double bond is indicated by the lowest–numbered carbon atom in the bond. CH 2 =CH–CH 2 –CH –butene Copyright © Cengage Learning. All rights reserved 15

Section 22.2 Alkenes and Alkynes Rules for Naming Alkynes  Same as for alkenes except use –yne as suffix. CH 3 –CH 2 –CΞC–CH 2 –CH 2 –CH 2 –CH 3 3–octyne Copyright © Cengage Learning. All rights reserved 16

Section 22.2 Alkenes and Alkynes Name each of the following: a) 2,3,5-trimethyl-2-hexene b) 6-ethyl-3-methyl-3-octene Copyright © Cengage Learning. All rights reserved 17 EXERCISE!

Section 22.3 Aromatic Hydrocarbons  A special class of cyclic unsaturated hydrocarbons.  Simplest of these is benzene (C 6 H 6 ).  The delocalization of the electrons makes the benzene ring behave differently from a typical unsaturated hydrocarbon. Copyright © Cengage Learning. All rights reserved 18

Section 22.3 Aromatic Hydrocarbons Benzene (Aromatic Hydrocarbon)

Section 22.4 Hydrocarbon Derivatives The Common Functional Groups Copyright © Cengage Learning. All rights reserved 20