ch27

Philip DuttonUniversity of Windsor, Canada

N9B 3P4

Prentice-Hall © 2002

General ChemistryPrinciples and Modern Applications

Petrucci • Harwood • Herring

8th Edition

Chapter 27: Organic Chemistry

Prentice-Hall © 2002 General Chemistry: Chapter 27 Slide 2 of 75

Contents

27-1 Organic Compounds and Structures: An Overview

27-2 Alkanes

27-3 Alkenes and Alkynes

27-4 Aromatic Hydrocarbons

27-5 Alcohols, Phenols, and Ethers

27-6 Aldehydes and Ketones

27-7 Carboxylic Acids and Their Derivatives

27-8 Amines

27-9 Heterocyclic Compounds


Contents

27-10 Nomenclature of Stereoisomers in Organic Compounds

27-11 An Introduction to Substitution Reactions at sp3 Hybridized Carbon Atoms

27-12 Synthesis of Organic Compounds

27-13 Polymerization Reactions

Focus On Natural and Synthetic Dyes


27-1 Organic Compounds and Structures: An Overview

• Hydrocarbons – the simplest organic compounds.• Simplest hydrocarbon is methane.


Ethane


Skeletal Isomerism

Prentice Hall © 2002 General Chemistry: Chapter 27 Slide 5 of


Simplified Drawings of Organic Structures


Nomenclature

• Select the longest continuous carbon chain.– This determines the base name.

• Consider each branch and name similarly except change the name from –ane to –yl.

• Number the C atoms so that substituents have the lowest possible number.


Nomenclature

• Name each substituent according to its identity and the number of the C atom to which it is attached.– Use di, tri, tetra as appropriate.

• Separate numbers from one another by commas.• List substituents alphabetically by name.


Table 27.1. Some Common Alkyl Groups


Positional Isomerism


Fun

ctio

nal G

roup

s


27-2 Alkanes


Conformations


Ring Structures


Ring Strain


Cyclohexane Conformations


Preparation of Alkanes

CH2=CH2 + H2 → CH3-CH3

Pt

Δ

2 CH3CH2Br + 2 Na → CH3CH2CH2CH3 + 2 NaBrpressure

Δ


Reactions of Alkanes

Initiation: Cl-Cl → 2 Cl·

Propagation: H3C-H + Cl· → H3C· + HCl

H3C· + Cl2 → H3C-Cl + Cl·

Termination:

H3C· + Cl· → H3C-Cl

Cl· + Cl· → Cl-Cl

H3C· + H3C· → H3C-CH3

Δ or h


Combustion Reactions

C8H18(l) + O2(g) → 8 CO2(g) + 9 H2O(l)25

2

ΔH° = -5.48103 J


Table 27.4 Principle Petroleum Fractions


Octane Number


27-3 Alkenes and Alkynes


Geometric Isomerism


Elimination Reaction


Addition Reactions

Markovnikov rule


Hydration Reaction

Addition is favored in dilute acid and elimination is favored in strong.


Reduction of C=C


27-4 Aromatic Hydrocarbons


Characteristics of Aromatic Hydrocarbons

• Planar (flat) cyclic molecules.• Conjugated п systems (4n + 2)


Naming Aromatic Hydrocarbons


Aromatic Substitution Reactions


Aromatic Subsitution Reactions


27-5 Alcohols, Phenols, and Ethers


Preparation and Use of Alcohols

CO(g) + 2 H2(g) → CH3OH(g)350 °C

200 atmZnO, Cr2O3


Preparation and Use of Alcohols

• Methanol.– 21st amongst industrial chemicals.

• Ethanol. – fermentation or by hydration of ethylene.

• Ehylene glycol.– High boiling point, soluble in water.

• Glycerin.


Ethers


Aldehydes and Ketones


Preparation and Use

• Oxidation of alcohols.

• Extract from natural sources

• Acetone is extensively used as a solvent.


Addition Reactions of the Carbonyl Group


27-7 Carboxylic Acids and Their Derivatives


Oxidation of Alcohols

CH3CH2OH + KMnO4 → CH3CO2-K+ → CH3CO2H

OH- H+


Aromatic Acids


Acetyl Group


Esters


Amides


Resonance in Amides


Reduction Reactions


Amines


Preparation of Amines

2 NH3 + CH3Br → CH3NH3+Br- + NH3 → CH3NH2 + NH4Br


Basicity of Amines


Ammonium Salts


27-9 Heterocyclic Compounds


27-10 Nomenclature of Stereoisomers in Organic Compounds


Chirality


The R,S System of Nomenclature

Substituent of higher atomic number takes precedence over one of lower atomic number:



If two substituents attached to the stereocenter have the same priority, proceed along the chains to the first point of difference:



Double and triple bonds count as if they were single and the atoms are duplicated or triplicated at the other end of the double or triple bond:


The E,Z System of Nomenclature


27-11 An Introduction to Substitution Reactions at sp3 Hybridized Carbon


SN2 Mechanism

Rate = k[OH-][CH3Cl]


Inversion of Configuration


SN1 Mechanism


SN1 Mechanism

Rate = k [(CH3)3CCl]


Racemic Products From SN1 Reactions


27-12 Synthesis of Organic Compounds


27-13 Polymerization Reactions


Table 27.5 Some Polymers Produced by Chain-Reaction Polymerization


Condensation Polymerization


Table 27.6 Some Polymers Produced by Step Reaction Polymerization


Stereospecific Polymers


Chapter 27 Questions

Develop problem solving skills and base your strategy not on solutions to specific problems but on understanding.

Choose a variety of problems from the text as examples.

Practice good techniques and get coaching from people who have been here before.

ch27

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