Chapter 4: Alkenes and Alkynes. Degree of unsaturation

Size: px
Start display at page:

Download "Chapter 4: Alkenes and Alkynes. Degree of unsaturation"

Transcription

1 hapter 4: Alkenes and Alkynes Unsaturated ydrocarbon: ontains one or more carbon-carbon double or triple bonds or benzene-like rings. Alkene: contains a carbon-carbon double bond and has the general formula n 2n. Alkyne: contains a carbon-carbon triple bond and has the general formula n 2n-2. Arene: benzene and its derivatives Note that benzene is a great example of resonance The reactivity of arenes is very different than the reactivity of alkenes. We do not study benzene and its derivatives until hapter 9. owever, we need know to the structure of the benzene molecule. And we need to know how to name a compound when benzene is used as a branch. When benzene is a branch, it is called the phenyl group. (benzyl has another meaning that we ll examine later.) The phenyl group does not react like an alkene or an alkyne (nor does benzene itself). Degree of unsaturation It can be helpful sometimes to compare an alkene, alkyne or cyclic hydrocarbon to an alkane with the same number of carbons. An unsaturated hydrocarbon will have fewer hydrogen atoms than a saturated hydrocarbon because it has double or triple bonds. Every extra carbon-carbon bond (double and triple bonds) or ring that an unsaturated hydrocarbon has is called a degree of unsaturation. Degrees of unsaturation can be determined by comparing the number of hydrogen atoms in a normal alkane (2n + 2) to the number of hydrogen atoms in the unsaturated compound. Subtract the number of hydrogens of the unsaturated compound from the number of hydrogens in the saturated compound and divide by two. Examples propene carbon alkane has 8 hydrogens, but propene has 6 hydrogens; therefore it has 1 degree of unsaturation. 1,3-hexadiene 2 6-carbon alkane has 14 hydrogens, but 1,3- hexadiene has 10 hydrogens; therefore it has 2 degrees of unsaturation. but-3-en-1-yne carbon alkane has 10 hydrogens, however, but-3-en-1-yne has 4 hydrogens; therefore, it has 3 degrees of unsaturation. 1

2 1,4-cyclohexadiene 2 2 Structure of Alkenes The two carbon atoms in a double bond and the four atoms bonded to them lie in a plane, with bond angles of approximately 120. Note the steric effect of the double bond and the methyl group. 6-carbon alkane has 14 hydrogens, but 1,4- cyclohexadiene has 8 hydrogens; therefore it has 3 degrees of unsaturation. Note the formation of the ring counts as a degree of unsaturation, even though cyclic alkanes aren t usually considered to be unsaturated hydrocarbons. According to the orbital overlap model, a double bond consists of one bond formed by the overlap of sp 2 hybrid orbitals and one bond formed by overlap of parallel 2p orbitals. Rotating by 90 breaks the pi bond. Thus, alkenes can have different geometric isomers, since there can be no rotation about the double bond. Geometrical Isomers of Alkenes The geometric isomers of an alkene have different chemical and physical properties. Because of steric strain between alkyl substituents of the same side of the double bond, a trans alkene is more stable than an isomeric cis alkene. The cis-trans system: configuration is determined by the orientation of atoms of the main chain. The cis isomer extends the carbon chain on the same side of the double bond. The trans isomer extends the carbon chain on different sides of the double bond. 2

3 Nomenclature of Alkenes IUPA nomenclature of alkenes Use the infix -en- to show the presence of a carboncarbon double bond. Number the parent chain to give the 1 st carbon of the double bond the lower number. Follow IUPA rules for numbering and naming substituents. For a cycloalkene, the numbering of the atoms of the ring the must begin with the two carbons of the double bond. Examples of IUPA alkene nomenclature 1-exene 2,3-Dimethylcyclohexene ommon nomenclature of alkenes Some alkenes, particularly low-molecular-weight ones, are known almost exclusively by their common names. E, Z onfigurations An alternative method to name geometric isomers is the E, Z method. To assign an E or Z configuration, first assign a priority to the substituents on each carbon of the double bond. If the groups of higher priority are on the same side of the double bond, the configuration is Z (German: zusammen, together). If the groups of higher priority are on opposite sides of the double bond, the configuration is E (German: entgegen, opposite). Priority rules (ahn-ingold-prelog rules) 1. Priority is based on atomic number; the higher the atomic number, the higher the priority. 3. Atoms participating in a double or triple bond are considered to be bonded to an equivalent number of similar atoms by single bonds. 2. If priority cannot be assigned on the basis of the atoms bonded directly to the double bond, look to the next set of atoms; priority is assigned at the first point of difference. 3

4 Examples: 1-bromo-1-chloropropene Examples: 2-chloro-2-pentene On the left side of the double bond, bromo has higher priority than chloro On the right side of the double bond, methyl has higher priority than hydrogen. igher priority is on the same side as the other higher priority; therefore, this compound is (Z)-1-bromo-1- chloropropene. On the left side of the double bond, chlorine has higher priority than methyl On the right side of the double bond, ethyl has higher priority than hydrogen. igher priority is opposite the other higher priority; therefore, this compound is (E)-2-chloro-2-pentene. Examples: 1-chloro-2,3-dimethyl-2-pentene Examples: 3,4-dimethyl-2-pentene On the left side of the double bond, chloromethyl has On the right side of the double bond, ethyl has igher priority is opposite the other higher priority; therefore, this compound is (E)-1-chloro-2,3-dimethyl- 2-pentene. On the left side of the double bond, methyl has higher priority than hydrogen On the right side of the double bond, isopropyl has igher priority is on same side as the other higher priority; therefore, this compound is (Z)-3,4-dimethyl- 2-pentene. Examples: 2,3,4-trimethyl-3-heptene On the left side of the double bond, propyl has On the right side of the double bond, isopropyl has igher priority is opposite the other higher priority; therefore, this compound is (E)-2,3,4-trimethyl-3- heptene. Other Instances of Geometric Isomerism ycloalkenes The configuration of the double bond in cyclopropene through cycloheptene must be cis. These rings are not large enough to accommodate a trans double bond. yclooctene is the smallest cycloalkene that can accommodate a trans double bond. 4

5 Dienes, trienes, and polyenes For an alkene with n carbon-carbon double bonds, each of which can show cis-trans isomerism, 2 n cistrans isomers are possible. onsider 2,4-heptadiene; it has four cis-trans isomers, two of which are drawn here below. onjugated Alkenes onjugated hydrocarbons have multiple double bonds that alternate with single bonds within a chain or a ring. 1,3-pentadiene is a conjugated alkene; whereas, 1,2-pentadiene or 1,4-pentadiene are not. 1,3-pentadiene (conjugated!) 1,2-pentadiene (an allene) 1,4-pentadiene onjugated alkenes have lower energies than nonconjugated alkenes. -electrons in bonds can be spread across more than two atoms. when electrons are less constrained, their energy decreases. For example, the p orbitals on carbons 1, 2, 3 and 4 of 1,3-pentadiene all overlap to create orbitals that involve all 4 of the first atoms in the hydrocarbon chain. onjugated systems have even numbers ( 4) of consecutive sp 2 atoms in its structure. Reactions with conjugated alkenes can give surprising results because the resonance structures with which conjugated systems can participate. Note the positive charge in the conjugated system is widely distributed because of resonance. 4 consecutive p orbitals can overlap to make conjugated system. p orbitals of neighboring pi bonds are perpendicular (can t make conjugated system). p orbitals on carbons 2 and 4 can t overlap (can t make conjugated system). 28 Natural Products The biochemical processes of organisms have strong (if not exclusive) preference for one geometric isomer over another. Vitamin A Vitamin A has five - double bonds. Four of the five can show cis-trans isomerism. Vitamin A is the all-trans isomer. O O O Fats Omega-3 fats have all cis configurations. Trans fats have all trans configurations. Trans fats are substituted for natural fats because they are cheaper to make. Saturated fats have no double bonds. Saturated fats are less expensive than trans fats. -linolenic acid (part of an omega-3 fat) O O elaidic acid (part of a trans fat) O stearic acid (part of a saturated fat) 5

6 Structure of Alkynes The functional group of an alkyne is a carboncarbon triple bond. A triple bond consists of: One bond formed by the overlap of sp hybrid orbitals. Two bonds formed by the overlap of sets of parallel 2p orbitals. Note the two bonds in an alkyne are perpendicular to each other. Nomenclature of Alkynes IUPA nomenclature of alkynes Use the infix -yn to show the presence of a carboncarbon triple bond. Number the parent chain to give the 1 st carbon of the triple bond the lower number. Follow IUPA rules for numbering and naming substituents. Physical Properties of Alkene and Alkynes Alkenes and alkynes are nonpolar compounds. The only attractive forces between their molecules are dispersion forces. The physical properties of alkenes and alkynes are similar to those of alkanes of similar carbon skeletons. Those that are liquid at room temperature are less dense than water (1.0 g/ml). They dissolve in each other and in nonpolar organic solvents. They are insoluble in water. The Peculiar Acidity of Terminal Alkynes One of the major differences between the chemistry of alkynes, relative to alkenes is that the hydrogen atom of a terminal alkyne is sufficiently acidic (pk a = 25) that it can be removed by a strong base such as sodium amide, NaN 2, to give an alkyne anion. The R : ion is also called an acetylide ion. Because water (pk a 15.7) is a stronger acid than acetylene or a terminal alkyne, hydroxide ion is not a strong enough base for an acid-base reaction with a terminal alkyne. 6

7 The pk a values for alkane and alkene hydrogens are so large that no base is strong enough to remove a hydrogen from either of these classes of compounds. Q: Why are terminal alkynes so acidic compared to alkenes and alkanes? A: Because the acetylide anion is a relatively stable ion. The lone pair of electrons of an alkane anion lies in an sp 3 hybrid orbital, which has 25% s character. For an alkene anion (also known as a vinyl anion), the lone pair lies in an sp 2 hybrid orbital, which has 33% s character. For an acetylide anion, the lone pair lies in an sp hybrid orbital, which has 50% s character. The greater the s character of the orbital bearing the negative charge, the greater the stability of the anion. The electron cloud of the lone pair gets closer to the nucleus and therefore has lower (more attractive) energy. Therefore, a terminal alkyne anion is the most stable of the series of hydrocarbon anions; and thus, a terminal alkyne is the most acidic. 7

Double bonds separated by more than one single bond are isolated. Compounds with isolated double bonds have the same chemical properties as alkenes.

Double bonds separated by more than one single bond are isolated. Compounds with isolated double bonds have the same chemical properties as alkenes. DIENES Dienes are alkenes with 2 double bonds. IUPA: Same as alkene, but change -ene to -adiene and use two numbers to locate the two double bonds (number from the end of the chain which makes the smaller

More information

Alkenes and Alkynes. Chapter 1.2

Alkenes and Alkynes. Chapter 1.2 Alkenes and Alkynes Chapter 1.2 Unsaturated Hydrocarbons Alkenes and alkynes are unsaturated hydrocarbons An alkene is a hydrocarbon that contains at least one carbon-carbon double bond An alkyne is a

More information

Chapter Thirteen. Alkenes, Alkynes, and Aromatic Compounds

Chapter Thirteen. Alkenes, Alkynes, and Aromatic Compounds Chapter Thirteen Alkenes, Alkynes, and Aromatic Compounds Saturated: A molecule whose carbon atoms bond to the maximum number of hydrogen atoms. Unsaturated: A molecule that contains a carbon carbon multiple

More information

C CH 2 H 3 C CH 2 CH 2 CH CH CH 3. 2-hexene

C CH 2 H 3 C CH 2 CH 2 CH CH CH 3. 2-hexene hapter 5: Structure and Preparation of Alkenes: Elimination eactions Alkenes (olefins) are hydrocarbons that contain a carbon-carbon double bond and are said to be "unsaturated." molecular formula n 2n

More information

the double or triple bond. If the multiple bond is CH 3 C CCHCCH 3

the double or triple bond. If the multiple bond is CH 3 C CCHCCH 3 Alkenes, Alkynes, and Aromatic ompounds Alkenes and Alkynes Unsaturated contain carbon-carbon double and triple bond to which more hydrogen atoms can be added. Alkenes: carbon-carbon double bonds Alkynes:

More information

Chapter 6 Alkenes I. IUPAC Rules for Alkene and Cycloalkene Nomenclature

Chapter 6 Alkenes I. IUPAC Rules for Alkene and Cycloalkene Nomenclature hapter 6 Alkenes I Naming Alkenes General Rule: replace ane with ene. No. of arbons IUPA Name ommon Name Formula n 2n Structure 2 Ethane ethylene 2 4 2 = 2 3 Propene propylene 3 6 2 = 3 4 1-Butene butylene

More information

Basic Organic Chemistry

Basic Organic Chemistry Basic Organic hemistry ourse code: EM 12162 (Pre-requisites : EM 11122) hapter 04 hemistry of Alkynes Dr. Dinesh R. Pandithavidana Office: B1 222/3 Phone: (+94)777-745-720 (Mobile) Email: dinesh@kln.ac.lk

More information

Chapter 25 The Chemistry of Life: Organic Chemistry. 25.1 Some General Characteristics of Organic Molecules

Chapter 25 The Chemistry of Life: Organic Chemistry. 25.1 Some General Characteristics of Organic Molecules Chapter 25 The Chemistry of Life: Organic Chemistry general characteristics of organic molecules introduction to hydrocarbons alkanes unsaturated hydrocarbons functional groups: alcohols and ethers compounds

More information

Alkenes and Alkynes. Consider these structural formulas for isomers of C 5 H 10 :

Alkenes and Alkynes. Consider these structural formulas for isomers of C 5 H 10 : Alkenes and Alkynes In organic chemistry, the term saturated refers to organic compounds which contain single carbon to carbon bonds or which have the maximum number of hydrogen atoms bonded to carbon

More information

LECTURE 1. ALKANES (PARAFFINS), ALKENES (OLEFINS), ALKYNES (ACETYLENES): GENERAL

LECTURE 1. ALKANES (PARAFFINS), ALKENES (OLEFINS), ALKYNES (ACETYLENES): GENERAL LECTURE 1. ALKANES (PARAFFINS), ALKENES (OLEFINS), ALKYNES (ACETYLENES): GENERAL Basic Nomenclature a saturated hydrocarbon is denoted by the suffix ANE an unsaturated hydrocarbon with one double bond

More information

Organic Chemistry. Hydrocarbons. Introduction to Organic Molecules. The simplest organic molecules containing only carbon and hydrogen atoms

Organic Chemistry. Hydrocarbons. Introduction to Organic Molecules. The simplest organic molecules containing only carbon and hydrogen atoms Introduction to Organic Molecules Organic Chemistry: (1828) Friedrich Wohler first synthesized an organic compound from an inorganic source leading to the birth of Organic Chemistry. Organic chemistry

More information

ALKENES, ALKYNES and AROMATIC COMPOUNDS Chapter 13

ALKENES, ALKYNES and AROMATIC COMPOUNDS Chapter 13 ALKENES, ALKYNES and AROMATIC COMPOUNDS Chapter 13 13.1 Introduction An ALKENE is a hydrocarbon with a double C bond that looks like C=C An ALKYNE is a hydrocarbon with a triple C bond that looks like

More information

Chapter 12 Unsaturated Hydrocarbons

Chapter 12 Unsaturated Hydrocarbons hapter 12 Unsaturated ydrocarbons 12.1 Alkenes and Alkynes opyright 2007 by Pearson Education, Inc. Publishing as Benjamin ummings Unsaturated ydrocarbons Unsaturated hydrocarbons ave fewer hydrogen atoms

More information

Organic Part 2. Reactivity of hydrocarbons addition reactions combustion reactions. Mary J. Bojan Chem 110

Organic Part 2. Reactivity of hydrocarbons addition reactions combustion reactions. Mary J. Bojan Chem 110 rganic Part 2 ydrocarbons 1. Alkanes: all single bonds 2. Alkenes: saturated v. unsaturated structural isomers geometric isomers 3. Alkynes: 4. Aromatic hydrocarbons eactivity of hydrocarbons addition

More information

11.1 Alkenes and Alkynes: Structure and Physical Properties. Chapter 11. Bonding and Geometry of Two-Carbon Molecules

11.1 Alkenes and Alkynes: Structure and Physical Properties. Chapter 11. Bonding and Geometry of Two-Carbon Molecules Denniston Topping Caret 6 th Edition!"#$%&'()!*+(,*-./%0123&44*!"5#06&,78*96.:**;,%5&77&"6*%,*?"%*%,#%">=.)&"6*"%*>&7#40$: Chapter 11 The Unsaturated Hydrocarbons: Alkenes, Alkynes, and Aromatic

More information

CHEM 121 Chapter 13. Name: Date:

CHEM 121 Chapter 13. Name: Date: CHEM 121 Chapter 13. Name: Date: 1. The common feature found in all unsaturated hydrocarbons is A) one or more carbon-carbon double bonds. B) one or more carbon-carbon triple bonds. C) one or more carbon-carbon

More information

6. Alkynes and An Introduction to Organic Synthesis. Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8

6. Alkynes and An Introduction to Organic Synthesis. Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8 6. Alkynes and An Introduction to Organic Synthesis Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8 Alkynes Hydrocarbons that contain carbon-carbon triple bonds Acetylene, the simplest alkyne

More information

II Alkanes, Alkenes, and Alkynes

II Alkanes, Alkenes, and Alkynes II Alkanes, Alkenes, and Alkynes Hydrocarbon: Compound composed of only carbon and hydrogen Saturated Hydrocarbons: Compound with only single bonds Unsaturated Hydrocarbons: Compounds with AT LEAST one

More information

Chapter 11 Unsaturated Hydrocarbons Alkenes and Alkynes

Chapter 11 Unsaturated Hydrocarbons Alkenes and Alkynes 1 Chapter 11 Unsaturated ydrocarbons Alkenes and Alkynes Saturated ydrocarbons 2 Saturated hydrocarbons have the maximum number of hydrogen atoms attached to each carbon atom are alkanes and cycloalkanes

More information

Chapter 9 Alkynes. Alkynes are hydrocarbons that contain a carbon-carbon triple bond. They have the formula C n H 2n-2. C C CH 3

Chapter 9 Alkynes. Alkynes are hydrocarbons that contain a carbon-carbon triple bond. They have the formula C n H 2n-2. C C CH 3 . 9 hapter 9 Alkynes Alkynes are hydrocarbons that contain a carbon-carbon triple bond. They have the formula n 2n-2. Nomenclature: The parent is the longest chain that contains the triple bond. hange

More information

It does not react N.R.

It does not react N.R. Benzene versus yclohexene versus yclohexadiene 1 l l cyclohexene l l cyclohexadiene l Expect this to react similarly "cyclohexatriene" It does not react l N.R. benzene Benzene is resonance stabilized,

More information

Last Time: Alkanes (C n H 2n+2 ) Last Time: Organic Compounds. Last Time: Intermolecular Forces- BP Increases w/ Increasing Size

Last Time: Alkanes (C n H 2n+2 ) Last Time: Organic Compounds. Last Time: Intermolecular Forces- BP Increases w/ Increasing Size Announcements & Agenda (0/02/07) Welcome Visitors! Please make yourselves comfortable; we will start with a quiz Mid-term grades are only based on lecture I will give you detailed grade sheets on Monday

More information

Chapter 13 Alkenes and Alkynes

Chapter 13 Alkenes and Alkynes hapter 13 Alkenes and Alkynes Types of Bonds Alkanes and haloalkanes consist of atoms held together by bonds. These can also be called sigma bonds (σ bonds) which means that the orbitals of each atom overlap

More information

Chapter 25. Organic and

Chapter 25. Organic and , The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 25 John D. Bookstaver St. Charles Community College Cottleville, MO Organic Organic chemistry is

More information

CHEM&152 Spring 2009 ORGANIC STRUCTURES, SHAPES AND ISOMERISM

CHEM&152 Spring 2009 ORGANIC STRUCTURES, SHAPES AND ISOMERISM EM&152 Spring 2009 ORGANI STRUTURES, SAPES AND ISOMERISM Fill-in Date Stamp here Name Partner Lecturer: Discussion In this experiment you will use molecular models to construct 3-dimensional models of

More information

Chapter 11 Alkynes 1

Chapter 11 Alkynes 1 Chapter 11 Alkynes 1 Alkynes Introduction Structure and Bonding Alkynes contain a carbon carbon triple bond. Terminal alkynes have the triple bond at the end of the carbon chain so that a hydrogen atom

More information

Alkenes: Alkynes: Example: What are all the structural possibilities for C 3 H 4? Unsaturated hydrocarbons: Bonding Patterns of Multiple Bonds

Alkenes: Alkynes: Example: What are all the structural possibilities for C 3 H 4? Unsaturated hydrocarbons: Bonding Patterns of Multiple Bonds Chapter 3 Organic Chem: Alkenes & Alkynes Don t need to know the following reactions found on summary pages 110-112: 1. Hydroboration-Oxidation 2. Cycloaddition to Conjugated Dienes 3. Alkyne reaction

More information

Alkenes and Alkynes: The Nature of Organic Reactions

Alkenes and Alkynes: The Nature of Organic Reactions Alkenes and Alkynes: The Nature of Organic Reactions Alkenes, sometimes called olefins, are hydrocarbons at contain a carbon carbon double bond, C=C, and alkynes are hydrocarbons at contain a carbon carbon

More information

Chemistry 307 Chapter 7 Structure and Synthesis of Alkenes

Chemistry 307 Chapter 7 Structure and Synthesis of Alkenes Organic hemistry Alkenes. D. oth hemistry 307 hapter 7 Structure and Synthesis of Alkenes Alkenes are hydrocarbons with (=) double bonds. Many alkenes occur in interesting natural products and others are

More information

AP Chemistry Chapter 22 - Organic and Biological Molecules

AP Chemistry Chapter 22 - Organic and Biological Molecules AP Chemistry Chapter - Organic and Biological Molecules.1 Alkanes: Saturated Hydrocarbons A. Straight-chain Hydrocarbons 1. Straight-chain alkanes have the formula C n H n+. Carbons are sp hybridized The

More information

Dienes & Polyenes: An overview and some key reactions (Ch )

Dienes & Polyenes: An overview and some key reactions (Ch ) Dienes & Polyenes: An overview and some key reactions (h. 14.1-14.5) Polyenes contain more than one double bond and are very common in natural products (ex: carotene). Diene chemistry applies to trienes,

More information

Assistant Lecture Aayad Ammar

Assistant Lecture Aayad Ammar Assistant Lecture Aayad Ammar Alkenes and Alkynes: Structure and Physical Properties Alkenes and alkynes are unsaturated hydrocarbons. The characteristic functional group of an alkene is the carbon-carbon

More information

Alkenes and Alkynes. Chapter Summary

Alkenes and Alkynes. Chapter Summary Alkenes and Alkynes hapter Summary Alkenes have a carbon-carbon double bond and alkynes have a carbon carbon triple bond. Nomenclature rules are given in Sec... Each carbon of a double bond is trigonal,

More information

Chem 101: General Chemistry Lecture 10 - Organic Compounds: Alkanes

Chem 101: General Chemistry Lecture 10 - Organic Compounds: Alkanes hem 101: General hemistry Lecture 10 - Organic ompounds: Alkanes I. arbon: The element of organic molecules A. Organic compounds are compounds that contain the element carbon 1. There are a few exceptions

More information

- Conjugated molecules have alternating single and multiple (i.e. double or triple) bonds.

- Conjugated molecules have alternating single and multiple (i.e. double or triple) bonds. Conjugated Molecules - Conjugated molecules have alternating single and multiple (i.e. double or triple) bonds. Example 1: Nomenclature: 2,6-dimethylhepta-2,5-diene This molecule is not conjugated because

More information

Prof. Jayaraman Sivaguru. Prof. Jayaraman Sivaguru

Prof. Jayaraman Sivaguru. Prof. Jayaraman Sivaguru hapter 9 Alkynes 9-1 Naturally Occurring Alkynes Some alkynes occur naturally. For example, O 3 ( 2 ) 10 ( 2 ) 4 O istrionicotoxin: defensive toxin in the poison dart frogs of entral and South America

More information

Chapter 7 Alkenes: Structure and Reactivity

Chapter 7 Alkenes: Structure and Reactivity John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 7 Alkenes: Structure and Reactivity Modified by Dr. Daniela Radu Alkene - Hydrocarbon With Carbon- Carbon Double Bond Also called an olefin but

More information

Alkanes. Chapter 1.1

Alkanes. Chapter 1.1 Alkanes Chapter 1.1 Organic Chemistry The study of carbon-containing compounds and their properties What s so special about carbon? Carbon has 4 bonding electrons. Thus, it can form 4 strong covalent bonds

More information

9/20/2010. Functional Groups. Functional Groups. Functional Groups

9/20/2010. Functional Groups. Functional Groups. Functional Groups Functional Groups Functional group A given functional group behaves in nearly the same way in every molecule it is a part of The chemistry of every organic molecule, regardless of size and complexity,

More information

Chapter 11 Unsaturated Hydrocarbons. Saturated Hydrocarbons. Unsaturated Hydrocarbons Alkenes and Alkynes

Chapter 11 Unsaturated Hydrocarbons. Saturated Hydrocarbons. Unsaturated Hydrocarbons Alkenes and Alkynes 1 hapter 11 Unsaturated ydrocarbons 11.1 Alkenes and Alkynes opyright 2009 by Pearson Education, Inc. 1 2 Saturated ydrocarbons Saturated hydrocarbons have the maximum number of hydrogen atoms attached

More information

Organic Chemistry. The Magic of Carbon

Organic Chemistry. The Magic of Carbon Organic Chemistry The Magic of Carbon Carbon What s special about carbon? 1. Forms 4 bonds. 2. It s bonds are stable, but not too stable. 3. It can covalently bond to numerous other elements. Why is that

More information

ORGANIC COMPOUNDS IN THREE DIMENSIONS

ORGANIC COMPOUNDS IN THREE DIMENSIONS (adapted from Blackburn et al., Laboratory Manual to Accompany World of hemistry, 2 nd ed., (1996) Saunders ollege Publishing: Fort Worth) Purpose: To become familiar with organic molecules in three dimensions

More information

What is Organic Chemistry? Organic chemistry is the chemistry of compounds which contain carbon.

What is Organic Chemistry? Organic chemistry is the chemistry of compounds which contain carbon. What is Organic Chemistry? Organic chemistry is the chemistry of compounds which contain carbon. Hydrocarbons Hydrocarbons are the simplest organic compounds. Contain only carbon and hydrogen. They can

More information

Benzene benzene aromatic hydrocarbons aromatic not not

Benzene benzene aromatic hydrocarbons aromatic not not Benzene 1 NT 87 90 ompound 87 has the formula 6 6, is known as benzene, and it is a hydrocarbon derived from petroleum distillates. Benzene is the parent compound for a class of compounds known as aromatic

More information

Organic Chemistry, Second Edition. Janice Gorzynski Smith University of Hawai i. Chapter 11 Alkynes

Organic Chemistry, Second Edition. Janice Gorzynski Smith University of Hawai i. Chapter 11 Alkynes Organic Chemistry, Second Edition Janice Gorzynski Smith University of Hawai i Chapter 11 Alkynes Prepared by Rabi Ann Musah State University of New York at Albany Copyright The McGraw-Hill Companies,

More information

Benzene appears to be remarkably stable and unreactive compared to an alkene such as cyclohexene or an alkane such as cyclohexane.

Benzene appears to be remarkably stable and unreactive compared to an alkene such as cyclohexene or an alkane such as cyclohexane. Aromatic Compounds Benzene appears to be remarkably stable and unreactive compared to an alkene such as cyclohexene or an alkane such as cyclohexane. When cyclohexene is allowed to react with bromine (an

More information

SCH4U: Summary of the Rules for Naming Organic Compounds

SCH4U: Summary of the Rules for Naming Organic Compounds SCH4U: Summary of the Rules for Naming Organic Compounds A) Rules for Naming Saturated Hydrocarbons 1) Identify the longest unbranched carbon backbone in the molecule (parent chain). (Do not confuse bends

More information

Chapter 4 Introduction to Organic Compounds

Chapter 4 Introduction to Organic Compounds Chapter 4 Introduction to Organic Compounds Outline 4.1 Alkanes: The Simplest Organic Compounds 4.2 Representing Structures of Organic Compounds 4.3 Families of Compounds Functional Groups 4.4 Nomenclature

More information

Chapter 11 Unsaturated Hydrocarbons. Saturated Hydrocarbons. Bond Angles in Alkenes and Alkynes. Unsaturated Hydrocarbons.

Chapter 11 Unsaturated Hydrocarbons. Saturated Hydrocarbons. Bond Angles in Alkenes and Alkynes. Unsaturated Hydrocarbons. Chapter 11 Unsaturated ydrocarbons 11.1 Alkenes and Alkynes Saturated ydrocarbons Saturated hydrocarbons have the maximum number of hydrogen atoms attached to each carbon atom. are alkanes and cycloalkanes

More information

Introduction to the Structures of Organic Molecules and Modeling their Shapes

Introduction to the Structures of Organic Molecules and Modeling their Shapes Introduction to the Structures of Organic Molecules and Objectives The objectives for this lab are: Part I: To learn the structures and construct models of simple organic molecules and draw their projection

More information

AP Chemistry Chapter 22 - Organic Chemistry

AP Chemistry Chapter 22 - Organic Chemistry AP Chemistry Chapter - Organic Chemistry.1 Alkanes: Saturated Hydrocarbons A. Straight-chain Hydrocarbons 1. Straight-chain alkanes have the formula C n H n+. Carbons are sp hybridized The First 10 Alkanes

More information

CHAPTER 20 UNSATURATED HYDROCARBONS SOLUTIONS TO REVIEW QUESTIONS

CHAPTER 20 UNSATURATED HYDROCARBONS SOLUTIONS TO REVIEW QUESTIONS APTER 20 UNSATURATED YDROARBONS SOLUTIONS TO REVIEW QUESTIONS 1. The sigma bond in the double bond of ethene is formed by the overlap of two electron orbitals and is symmetrical about a line drawn between

More information

Chapter 13. Conjugated Unsaturated Systems. Conjugation, Resonance and Dienes. Conjugation, Resonance and Dienes. What is the conjugation?

Chapter 13. Conjugated Unsaturated Systems. Conjugation, Resonance and Dienes. Conjugation, Resonance and Dienes. What is the conjugation? Chapter 13 Conjugation, Resonance and Dienes What is the conjugation? Conjugation occurs whenever p orbitals are located on three or more adjacent atoms. Conjugated Unsaturated Systems The four p orbitals

More information

Chapter 18 Organic Chemistry I: The Hydrocarbons

Chapter 18 Organic Chemistry I: The Hydrocarbons Key oncepts Overview hapter 18 Organic hemistry I: The ydrocarbons Aliphatic ydrocarbons (Sections 18.1 18.7) hydrocarbons, types of hydrocarbons, aliphatic hydrocarbon, aromatic hydrocarbon, condensed

More information

Pre-lab 2: Naming and Modeling Organic Compounds

Pre-lab 2: Naming and Modeling Organic Compounds Name: Pre-lab 2: Naming and Modeling Organic Compounds Section: Read the background information and answer the following questions before lab. 1. Write the electron-dot formula for ethane and determine

More information

Chapter 8: Chemistry of Alkynes (C n H 2n-2 )

Chapter 8: Chemistry of Alkynes (C n H 2n-2 ) hapter 8: hemistry of Alkynes ( n 2n-2 ) Bonding & hybridization Both are sp-hybridized Bond angles = 180 o 1 σ + 2 π bonds Linear around lassification R R R' σ bond energy: 88 kcal/mol π bond energy:

More information

Chapter 3: Structure and Nomenclature of Organic Compounds Focus on Alkanes

Chapter 3: Structure and Nomenclature of Organic Compounds Focus on Alkanes hapter 3: Structure and Nomenclature of rganic ompounds Focus on Alkanes rganic molecules are composed of one or more functional groups attached to one or more hydrocarbon groups (alkyl or groups) I. Functional

More information

Reduction: Hydrogenation

Reduction: Hydrogenation Reduction: ydrogenation 1 Addition of one molar equivalent of hydrogen (-) will generate a diene and addition of two molar equivalents of -) will give an alkene. Complete reduction of benzene to cyclohexane

More information

Chapter 2: Structure and Properties of Organic Molecules

Chapter 2: Structure and Properties of Organic Molecules Chapter 2: Structure and Properties of Organic Molecules Atomic Orbitals (2.1-2.5) Wave functions that represent the probability of finding electrons in a specific region of space s, p, d, f orbitals In

More information

Unsaturation. Degree of Unsaturation (Index of Hydrogen Deficiency) Copyright 2004 by Carl H. Snyder, University of Miami. All rights reserved.

Unsaturation. Degree of Unsaturation (Index of Hydrogen Deficiency) Copyright 2004 by Carl H. Snyder, University of Miami. All rights reserved. Chemistry 201 C Alkenes: Structure and Reactivity This presentation was created by Professor Carl H. Snyder Chemistry Department University of Miami Coral Gables, FL 33124 CSnyder@miami.edu Copyright 2004

More information

ORGANIC AND BIOLOGICAL MOLECULES

ORGANIC AND BIOLOGICAL MOLECULES APTER TWENTY-TW RGANI AND BILGIAL MLEULES For Review 1. A hydrocarbon is a compound composed of only carbon and hydrogen. A saturated hydrocarbon has only carbon-carbon single bonds in the molecule. An

More information

Alkanes and Cycloalkanes

Alkanes and Cycloalkanes Alkanes and Cycloalkanes Chapter 2 1 Structure ydrocarbon: A compound composed only of carbon and hydrogen. Saturated hydrocarbon: A hydrocarbon containing only single bonds. Alkane: A saturated hydrocarbon

More information

Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes

Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes 1) Carbon-Carbon Bonding in Alkanes (C-C), Alkenes (C=C) and Alkynes (C C). Understand the hybridization of atomic orbitals (ground state promotion

More information

standing waves (guitar string, blow into beer bottle).

standing waves (guitar string, blow into beer bottle). Structure and Properties of Organic Molecules Electrons exhibit wave-particle duality. There are 2 types of wave: travelling waves (ripples on a pond) standing waves (guitar string, blow into beer bottle).

More information

4.2 NOMENCLATURE OF ALKENES

4.2 NOMENCLATURE OF ALKENES 4.2 NOMENCLATURE OF ALKENES 131 PROBLEM 4.1 Which of the following alkenes can exist as double-bond stereo? Identify the stereocenters in each. (a) H 2 C A 2 2 (b) 2 A 2 1-pentene 3-hexene (c) H 2 C A

More information

Saturday X-tra X-Sheet: 8

Saturday X-tra X-Sheet: 8 Saturday X-tra X-Sheet: 8 Organic Molecules ydrocarbons Key oncepts This lesson will focus on the following; Organic chemistry ydrocarbons Saturated hydrocarbons Unsaturated hydrocarbons Isomers omologous

More information

Chapter 22, Organic Chemistry

Chapter 22, Organic Chemistry Chapter 22, Organic Chemistry I. The Nature of Organic Molecules A. C is tetravalent. Implications? B. C forms covalent bonds. Could you have predicted? 1. Non-polar 2. Polar C. C forms single, double,

More information

3. The Nature of Organic Reactions: Alkenes Alkenes (olefins): hydrocarbons that contain a carbon-carbon double bond, C=C.

3. The Nature of Organic Reactions: Alkenes Alkenes (olefins): hydrocarbons that contain a carbon-carbon double bond, C=C. 3. The Nature of Organic Reactions: Alkenes Alkenes (olefins): hydrocarbons that contain a carbon-carbon double bond, C=C. Abundant in nature, playing important biological roles. Ethylene (C 2 =C 2 ) a

More information

HYDROCARBONS. Types of Hydrocarbons HYDROCARBONS. Question 2.2. Question 2.1. Chapter 2. What is the hybridization of the starred carbon of geraniol?

HYDROCARBONS. Types of Hydrocarbons HYDROCARBONS. Question 2.2. Question 2.1. Chapter 2. What is the hybridization of the starred carbon of geraniol? hapter 2 Introduction to ydrocabons arbon Backbone, Nomenclature, Physical & hemical Properties YDRARBNS ompounds composed of only carbon and hydrogen atoms (, ). Each carbon has 4 bonds. They represent

More information

Chapter 23, Organic Chemistry

Chapter 23, Organic Chemistry Chapter 23, Organic Chemistry I. The Nature of Organic Molecules A. C is tetravalent. Implications? B. C forms covalent bonds. Could you have predicted? 1. Non-polar 2. Polar C. C forms single, double,

More information

Chapter 7 - Alkenes and Alkynes I

Chapter 7 - Alkenes and Alkynes I Andrew Rosen Chapter 7 - Alkenes and Alkynes I 7.1 - Introduction - The simplest member of the alkenes has the common name of ethylene while the simplest member of the alkyne family has the common name

More information

Chem 350 Jasperse Ch. 2 Handouts 1

Chem 350 Jasperse Ch. 2 Handouts 1 hem 350 Jasperse h. 2 Handouts 1 Hybrid rbitals (Sections 2.4, 2.6); π bonding (Section 2.3) 1s + 3p 4 sp 3 hybrids 109º 1s + 2p (+ 1 unhybridized p) 3 sp 2 hybrids (+ 1 unhybridized p) 120º 1s + 1p (+

More information

UNIT (7) ORGANIC COMPOUNDS: HYDROCARBONS

UNIT (7) ORGANIC COMPOUNDS: HYDROCARBONS UNIT (7) ORGANIC COMPOUNDS: YDROCARBONS Organic chemistry is the study carbon containing compounds. 7.1 Bonding in Organic Compounds Organic compounds are made up of only a few elements and the bonding

More information

Survival Organic Chemistry Part I: Molecular Models

Survival Organic Chemistry Part I: Molecular Models Survival Organic Chemistry Part I: Molecular Models The goal in this laboratory experience is to get you so you can easily and quickly move between empirical formulas, molecular formulas, condensed formulas,

More information

4. Draw an acceptable line angle formula for the compound shown below.

4. Draw an acceptable line angle formula for the compound shown below. 4. Draw an acceptable line angle formula for the compound shown below. 5. Rank these compounds in order of increasing acidity (1 being least acidic, 3 being most acidic) N 3 F 2 6. Draw either a correct

More information

Chapter 11 Organic Compounds: Alkanes

Chapter 11 Organic Compounds: Alkanes Spencer L. Seager Michael R. Slabaugh www.cengage.com/chemistry/seager Chapter 11 Organic Compounds: Alkanes Jennifer P. Harris ORGANIC COMPOUNDS In 1828, Friedrich Wöhler first synthesized an organic

More information

Chapter 6. Alkenes: Structure and Stability

Chapter 6. Alkenes: Structure and Stability hapter 6. Alkenes: Structure and Stability Steric Acid (saturated fatty acid) Linoleic Acid (unsaturated fatty acid) Degrees of unsaturation saturated hydrocarbon n 2n2 cycloalkane (1 ring) n 2n alkene

More information

Alkynes: An Introduction to Organic Synthesis

Alkynes: An Introduction to Organic Synthesis Alkynes: An Introduction to Organic Synthesis Alkynes Hydrocarbons that contain carbon-carbon triple bonds Acetylene, the simplest alkyne is produced industrially from methane and steam at high temperature

More information

Chapter 4 Lecture Notes

Chapter 4 Lecture Notes Chapter 4 Lecture Notes Chapter 4 Educational Goals 1. Given the formula of a molecule, the student will be able to draw the line-bond (Lewis) structure. 2. Understand and construct condensed structural

More information

1) Systematic naming of alkanes 2) Alkenes 3) Alkynes 4) Aromatic compounds (benzene etc) 5) Hydrocarbon physical properties 6) Petroleum chemistry

1) Systematic naming of alkanes 2) Alkenes 3) Alkynes 4) Aromatic compounds (benzene etc) 5) Hydrocarbon physical properties 6) Petroleum chemistry Chem 106 Tues 1-25-2011 1) Systematic naming of alkanes 2) Alkenes 3) Alkynes 4) Aromatic compounds (benzene etc) 5) ydrocarbon physical properties 6) Petroleum chemistry 1/25/2011 1 pencil : paper ::

More information

Name Date Class STUDY GUIDE FOR CONTENT MASTERY. Alkanes In your textbook, read about organic chemistry, hydrocarbons, and straight-chain alkanes.

Name Date Class STUDY GUIDE FOR CONTENT MASTERY. Alkanes In your textbook, read about organic chemistry, hydrocarbons, and straight-chain alkanes. ydrocarbons Section 22.1 Alkanes In your textbook, read about organic chemistry, hydrocarbons, and straight-chain alkanes. Use each of the terms below just once to complete the passage. hydrocarbons homologous

More information

General Chemistry II. Dr Rick Attrill. Office MHMK 1405/5. Classification of Hydrocarbons. Common Elements in Organic Compounds. Organic Chemistry I

General Chemistry II. Dr Rick Attrill. Office MHMK 1405/5. Classification of Hydrocarbons. Common Elements in Organic Compounds. Organic Chemistry I Organic hemistry I General hemistry II Dr Rick Attrill 202102 Office MMK 1405/5 lasses of Organic ompounds Aliphatic ydrocarbons Alkanes ycloalkanes Alkenes Alkynes Aromatic ydrocarbons 1 2 ommon Elements

More information

Alkynes: An Introduction to Organic Synthesis. Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8

Alkynes: An Introduction to Organic Synthesis. Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8 Alkynes: An Introduction to Organic Synthesis Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8 Alkynes! Hydrocarbons that contain carbon-carbon triple bonds! Acetylene, the simplest alkyne

More information

Holt Chemistry Chapter 19 Carbon and Organic Compounds

Holt Chemistry Chapter 19 Carbon and Organic Compounds 19-1 Alkanes Describe the structures of alkanes. Name an alkane by examining its structure. Draw the structure of an alkane given its name. Holt Chemistry Chapter 19 Carbon and Organic Compounds A. Organic

More information

Alkanes. Hydrocarbons. Structural Isomers. Butane Isomers. Contain only carbon and hydrogen

Alkanes. Hydrocarbons. Structural Isomers. Butane Isomers. Contain only carbon and hydrogen ydrocarbons Alkanes ontain only carbon and hydrogen ydrocarbons Alkanes Alkenes Alkynes Aromatics General formula n 2n+2 Each carbon is sp 3 hybridized Bond angles are 109.5 o Methane Ethane Propane Butane

More information

Chapter 15 Benzene and Aromaticity

Chapter 15 Benzene and Aromaticity John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 15 Benzene and Aromaticity Aromatic Compounds Aromatic was used to described some fragrant compounds in early 19 th century Not correct: later

More information

DEPARTMENT OF CHEMISTRY & CHEMICAL TECHNOLOGY

DEPARTMENT OF CHEMISTRY & CHEMICAL TECHNOLOGY DEPARTMENT OF CHEMISTRY & CHEMICAL TECHNOLOGY FINAL EXAMINATION CHEMISTRY 202-BZF-05 Monday, December 13, 2010 2:00 PM - 5:00 PM Name: SOLUTION Student Number: Final Examination Rules Before you begin

More information

Hydrocarbons Part 1: Structural Formulas

Hydrocarbons Part 1: Structural Formulas ydrocarbons Part 1: Structural Formulas Structural Formulas for Organic Molecules ondensed Skeletal-line Lewis (Expanded) 1 Neutral Bonding Patterns for Organic ompounds 2 Skeletal Line Structures arbon

More information

TOPIC 3. ALKANES (chapter 4 and parts of chapters 7 and 10)

TOPIC 3. ALKANES (chapter 4 and parts of chapters 7 and 10) L TOPIC 3. ALKANES (chapter 4 and parts of chapters 7 and 10) OBJECTIVES 1. Develop rules for systematic nomenclature of alkanes alkenes and alkynes 2. Describe the geometry of hydrocarbons 3. Describe

More information

Stability of vinyl C+ is about the same as H 3 C+. NOT ASSISTED!

Stability of vinyl C+ is about the same as H 3 C+. NOT ASSISTED! rganic hemistry Interactive Notes hapter 8: Alkynes Naming Alkynes Structure ommon Name IUPA Acetylene ethyne methyl acetylene propyne dimethyl acetylene -butyne ethyl acetylene -butyne =- as substituent

More information

Hydrocarbons. Organic structures that contain only carbon and hydrogen

Hydrocarbons. Organic structures that contain only carbon and hydrogen ydrocarbons Organic structures that contain only carbon and hydrogen Saturated a compound is termed saturated if it has the maximum hybridization (sp 3 ) at each carbon Therefore: no double or triple bonds

More information

Electron Geometry. Remaining P-orbitals 4 Tetrahedral 109º sp Trigonal 120º sp 2 1. Bond Angle Hybridization B+L. 2 Linear 180º sp 2 EXAMPLES

Electron Geometry. Remaining P-orbitals 4 Tetrahedral 109º sp Trigonal 120º sp 2 1. Bond Angle Hybridization B+L. 2 Linear 180º sp 2 EXAMPLES hem 350 Jasperse h. 2 andouts 1 VSEPR : Valence Shell Electron Pair Repulsion (Sections 2.4, 2.6) oncept: electron groups repel, determine structure 4 electron groups: tetrahedral, 109º angle 3 electron

More information

1. Organic chemistry can be defined as the chemistry of carbon-containing compounds.

1. Organic chemistry can be defined as the chemistry of carbon-containing compounds. 241Practice Exam #1 Study omework as well!! True/False Indicate whether the sentence or statement is true or false. 1. Organic chemistry can be defined as the chemistry of carbon-containing compounds.

More information

Chapter 10. Conjugation in Alkadienes and Allylic Systems. Class Notes. B. The allyl group is both a common name and an accepted IUPAC name

Chapter 10. Conjugation in Alkadienes and Allylic Systems. Class Notes. B. The allyl group is both a common name and an accepted IUPAC name Chapter 10 Conjugation in Alkadienes and Allylic Systems Chapter 10 suggested problems: I. The allyl group Class Notes A. B. The allyl group is both a common name and an accepted IUPAC name 1. Allyl alcohol

More information

Chapter 10: Organic chemistry fast facts

Chapter 10: Organic chemistry fast facts Chapter 10: Organic chemistry fast facts 10.1 Fundamentals of organic chemistry Organic chemistry focuses on the chemistry of compounds containing carbon. A homologous series is a series of compounds with

More information

Note that when two equivalents of HX are added to a terminal alkyne, both X s wind up on the same carbon!

Note that when two equivalents of HX are added to a terminal alkyne, both X s wind up on the same carbon! Reactions of Alkynes: 1. Addition of X (Addn of, X, where X = Cl, ) Markovnikov 1x or 2x Types of Alkynes Terminal one end is substituted with R and one has an. The end with the R is more substituted,

More information

Chemistry B11 Chapters Alkanes, Alkenes, Alkynes and Benzene

Chemistry B11 Chapters Alkanes, Alkenes, Alkynes and Benzene Chemistry B11 Chapters 10-13 Alkanes, Alkenes, Alkynes and Benzene Organic compounds: organic chemistry is the chemistry of carbon and only a few other elements-chiefly, hydrogen, oxygen, nitrogen, sulfur,

More information

Chapter 15. AgCl(s) + NH 4 CNO(aq)

Chapter 15. AgCl(s) + NH 4 CNO(aq) Chapter 15 WHY ARE THERE SO MANY CARBON COMPOUNDS I? Up to this chapter, the focus has been on inorganic compounds. Yet of the millions of known chemical compounds, the vast majority are organic compounds.

More information

Chemistry 1110 Organic Chemistry IUPAC Nomenclature

Chemistry 1110 Organic Chemistry IUPAC Nomenclature hemistry 1110 rganic hemistry IUPA Nomenclature 1 f the approximately 32 million unique chemical compounds presently known, over 95% of them can be classified as organic; i.e., containing carbon. The IUPA

More information

Chapter 12 Alkenes, Alkynes, and Aromatic Compounds

Chapter 12 Alkenes, Alkynes, and Aromatic Compounds hapter 12 Alkenes, Alkynes, and Aromatic ompounds ompounds with multiple bonds The most important compound with a triple bond is ethyne also known as acetylene; it is used in the oxy acetylene torch. Bombykol,

More information