Chapter 23 Functional Groups 23.1 Introduction to Functional Groups 23.2 Alcohols, Ethers, and Amines 23.3 Carbonyl Compounds 23.4 Polymers Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

CHEMISTRY & YOU How can you tell the difference between one organic compound and another? From a distance, all the musicians look nearly identical. But are they? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

How are organic compounds classified? Functional Groups Functional Groups How are organic compounds classified? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Functional Groups In most organic reactions, the saturated hydrocarbon skeletons of molecules are chemically inert, or non-reactive. So how, then, can there be hundreds of different kinds of organic reactions? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Functional Groups Most organic chemistry involves substituents, which are groups attached to hydrocarbon chains or rings. The substituents of organic molecules often contain oxygen, nitrogen, sulfur, and/or phosphorus. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Functional Groups Most organic chemistry involves substituents, which are groups attached to hydrocarbon chains or rings. The substituents of organic molecules often contain oxygen, nitrogen, sulfur, and/or phosphorus. They are called functional groups because they are the chemically functional parts of the molecules. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Functional Groups A functional group is a specific arrangement of atoms in an organic compound that is capable of characteristic chemical reactions. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Functional Groups A functional group is a specific arrangement of atoms in an organic compound that is capable of characteristic chemical reactions. Note that the double and triple bonds of alkenes and alkynes are chemically reactive. Therefore, they are also considered functional groups. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Functional Groups Organic compounds can be classified according to their functional groups. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Organic Compounds Classified by Functional Group Interpret Data Organic Compounds Classified by Functional Group Compound type General structure Functional group Halocarbon Halogen Carboxylic acid Carbonyl Alcohol Hydroxy Ether Ester Amine Amino Aldehyde Amide Ketone In each general structure listed, the symbol R represents any carbon chains or rings attached to the functional group. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Organic Compounds Classified by Functional Group Interpret Data Organic Compounds Classified by Functional Group Compound type General structure Functional group Halocarbon Halogen Carboxylic acid Carbonyl Alcohol Hydroxy Ether Ester Amine Amino Aldehyde Amide Ketone In some cases, R can be a hydrogen atom. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Organic Compounds Classified by Functional Group Interpret Data Organic Compounds Classified by Functional Group Compound type General structure Functional group Halocarbon Halogen Carboxylic acid Carbonyl Alcohol Hydroxy Ether Ester Amine Amino Aldehyde Amide Ketone When more than one R group is shown in the structural formula, the groups do not need to be the same. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Are functional groups always substituents on a hydrocarbon? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Are functional groups always substituents on a hydrocarbon? No. Alkenes and alkynes are also chemically reactive. Therefore double and triple bonds can be considered functional groups, but they are not substituents. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

What is the general formula of a halocarbon? Halocarbons Halocarbons What is the general formula of a halocarbon? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

What is the general formula of a halocarbon? Halocarbons Halocarbons What is the general formula of a halocarbon? A halocarbon is an organic compound that contains at least one covalently bonded fluorine, chlorine, bromine, or iodine atom. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Halocarbons The general formula of a halo carbon is RX, where X is a halogen substituent. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Halocarbons The IUPAC rules for naming halocarbons are based on the name of the parent hydrocarbon. The halogen groups are named as substituents. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Halocarbons The IUPAC rules for naming halocarbons are based on the name of the parent hydrocarbon. The halogen groups are named as substituents. Chloromethane Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Halocarbons The IUPAC rules for naming halocarbons are based on the name of the parent hydrocarbon. The halogen groups are named as substituents. Chloroethene Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Halocarbons The IUPAC rules for naming halocarbons are based on the name of the parent hydrocarbon. The halogen groups are named as substituents. Chlorobenzene Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Common names of halocarbons consist of two parts. The first part names the hydrocarbon portion of the molecule as an alkyl group, such as methyl- or ethyl-. The second part names the halogen with an -ide ending. Methyl chloride Vinyl chloride Phenyl chloride Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Halocarbons On the basis of their common names, a halocarbon in which a halogen is attached to a carbon of an aliphatic chain is called an alkyl halide. A halocarbon in which a halogen is attached to a carbon of an arene ring is called an aryl halide. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Some Common Substituent Groups Interpret Data Some Common Substituent Groups Name Group structure Isopropyl Tertiary butyl (tert-butyl) Isobutyl Vinyl Secondary butyl (sec-butyl) Phenyl Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Halocarbons The attractions between halocarbon molecules are primarily the result of weak van der Waals interactions. Generally, these attractions increase with the degree of halogen substitution. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Comparing Methane and Chloromethanes Interpret Data More highly halogenated organic compounds have higher boiling points. Comparing Methane and Chloromethanes Molecular formula Name Molar mass (g) Boiling point (°C) CH4 Methane 16.0 –161 CH3Cl Chloromethane (methyl chloride) 50.5 –24 CH2Cl2 Dichloromethane (methylene chloride) 85.0 40 CHCl3 Trichloromethane (chloroform) 119.5 61 CCl4 Tetrachloromethane (carbon tetrachloride) 154.0 74 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Halocarbons Very few halocarbons are found in nature, but they can be readily prepared and used for many purposes. For example, hydrofluorocarbons (HFCs) are used as refrigerants in automobile air-conditioning systems. Halocarbons are also used as solvents and as ingredients of stretchable polymers. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

What is the difference between an alkyl halide and an aryl halide? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

What is the difference between an alkyl halide and an aryl halide? An alkyl halide is a halocarbon in which a halogen is attached to a carbon of an aliphatic chain. An aryl halide is a halocarbon in which a halogen is attached to a carbon of an arene ring. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions How are substitution reactions used in organic chemistry? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions Organic reactions often proceed more slowly than inorganic reactions because organic reactions commonly involve the breaking of relatively strong covalent bonds. They often require catalysts. Many organic reactions are complex, and they usually produce a mixture of products. The desired product must then be separated by distillation, crystallization, or other means. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions A common type of organic reaction is a substitution reaction, in which an atom, or a group of atoms, replaces another atom or group of atoms. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions Substitution reactions are an important method of introducing new functional groups to organic molecules. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions A halogen atom can replace a hydrogen atom on an alkane to produce a halocarbon. The symbol X stands for a halogen in this generalized equation. R—H + X2 → R—X + HX Alkane Halogen Halocarbon Hydrogen halide Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions A halogen atom can replace a hydrogen atom on an alkane to produce a halocarbon. The symbol X stands for a halogen in this generalized equation. R—H + X2 → R—X + HX Alkane Halogen Halocarbon Hydrogen halide This type of reaction is also called a halogenation reaction because the reaction introduces a halogen atom into the molecule. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions Sunlight or another source of ultraviolet radiation usually serves as a catalyst. UV light CH4 + Cl2 → CH3Cl + HCl Methane Chlorine Chloromethane Hydrogen chloride Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions Sunlight or another source of ultraviolet radiation usually serves as a catalyst. UV light CH4 + Cl2 → CH3Cl + HCl Methane Chlorine Chloromethane Hydrogen chloride Even under the most controlled conditions, this simple substitution reaction produces a mixture of mono-, di-, tri-, and tetrachloromethanes. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions Halogenation of benzene in the presence of a catalyst causes the substitution of a hydrogen atom on the ring. Iron compounds are often used as catalysts for substitution reactions in aromatic compounds. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions Halocarbons can be converted to other types of compounds by substitution reactions. Hydroxide ions can displace halogen atoms on carbon chains to form an alcohol. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions Chemists usually use aqueous solutions of sodium hydroxide or potassium hydroxide as the source of hydroxide ions. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Substitution Reactions Halocarbons can also be converted to other halocarbons, amines, or ethers by similar substitution reactions. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

CHEMISTRY & YOU Earlier you learned that adding a halogen substituent to a hydrocarbon affects certain physical properties. How can you distinguish between hydrocarbons and halocarbons in terms of structures and properties? Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

CHEMISTRY & YOU Earlier you learned that adding a halogen substituent to a hydrocarbon affects certain physical properties. How can you distinguish between hydrocarbons and halocarbons in terms of structures and properties? A halocarbon will contain at least one covalently bonded fluorine, chlorine, bromine, or iodine atom. Halocarbons are more reactive than hydrocarbons, and have higher boiling points. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Name two kinds of substitution reactions used in organic chemistry. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Name two kinds of substitution reactions used in organic chemistry. There are substitution reactions in which a halogen reacts with an alkane to produce a halocarbon, and substitution reactions in which a hydroxide ion reacts with a halocarbon to form an alcohol. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Key Concepts Organic compounds can be classified according to their functional groups. The general formula of a halocarbon is RX, where X is a halogen substituent. Substitution reactions are an important method of introducing new functional groups to organic molecules. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Glossary Terms functional group: a specific arrangement of atoms in an organic compound that is capable of characteristic chemical reactions; the chemistry of an organic compound is determined by its functional groups halocarbon: any member of a class of organic compounds containing covalently bonded fluorine, chlorine, bromine, or iodine Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Glossary Terms alkyl halide: a halocarbon in which one or more halogen atoms are attached to the carbon atoms of an aliphatic chain aryl halide: a halocarbon in which one or more halogens are attached to the carbon atoms of an arene ring substitution reaction: a common type of organic reaction; involves the replacement of an atom or group of atoms by another atom or group of atoms Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Carbon Chemistry and Reactions BIG IDEA Carbon Chemistry and Reactions Functional groups affect the physical and chemical properties of organic compounds. Chemical reactions can be used to change the structure of organic molecules, often by introducing a new functional group. Substitution reactions are commonly used in organic chemistry. Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

END OF 23.1 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.