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Organic Chemistry - Lecture notes - Chem261 Notes
Organic Chemistry (University of Alberta)
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Chemistry 261 W2015 Lecture Notes I
CH EM 2 6 1 – I nt roduc t ory Orga nic Che m ist ry I
Cla ss N ot e s
Instructor: Christopher Cairo
University of Alberta
Department of Chemistry
CAIRO – University of Alberta 1
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Chemistry 261 W2015 Lecture Notes I
Table of Contents
I . I nt roduc t ion a nd re vie w ....................................................................... 6
Organic Chemistry ....................................................................................................... 6
Atomic Structure - The Atomic Model .......................................................................... 7
Atomic Structure – Orbitals .......................................................................................... 7
Formal Charge ........................................................................................................... 11
Resonance ................................................................................................................ 13
Resonance Forms ..................................................................................................... 13
Formal Charges in Resonance Forms ....................................................................... 15
Some notes on Drawing Organic Structures: ............................................................. 11
Acids and Bases - Brønsted-Lowry (BL) Theory ........................................................ 16
Prediction of Direction of Acid-Base Reactions From pKa’s ....................................... 18
Acids and Bases in Aqueous Media .......................................................................... 19
Prediction of Acid Strength – Factors Influencing Acidity........................................... 21
Inductive effects ......................................................................................................... 22
Atom hybridization ..................................................................................................... 23
Acids and Bases - Lewis Definition ............................................................................ 23
I I . St ruc t ure a nd prope rt ie s of orga nic m ole c ule s ................................ 2 5
Chemical Bonding...................................................................................................... 25
Rules for forming Molecular Orbitals (MO) ................................................................ 29
Hybridization of Orbitals............................................................................................. 30
Structure of Ethane - CH3CH3 .................................................................................... 31
Structure of Ethylene (CH2=CH2) ............................................................................... 31
Structure of Acetylene (HCCH) ................................................................................ 33
Effect of Hybridization on Bond Lengths and Strengths............................................. 34
Hybridization of Nitrogen, Oxygen and Boron ............................................................ 34
VSEPR Model ............................................................................................................ 37
Physical Properties of Organic Molecules ................................................................. 37
Important Intermolecular Interactions ........................................................................ 37
Influence of Intermolecular Interactions on Physical Properties ................................ 39
Water solubility – trends. ........................................................................................... 41
Functional Groups ..................................................................................................... 42
Summary of Common Functional Groups .................................................................. 42
Alkyl Groups .............................................................................................................. 44
R groups .................................................................................................................... 44
Further Classification of Functional Groups Based on Degree of Substitution .......... 44
I I I . I nfra re d Spe c t rosc opy ...................................................................... 4 6
Absorption Spectroscopy ........................................................................................... 46
Infrared (IR) Spectroscopy ......................................................................................... 47
General IR Absorption Trends ................................................................................... 48
Spectral Regions ....................................................................................................... 48
Important Absorptions................................................................................................ 48
Effect of Structure on Carbonyl Stretching Absorption............................................... 49
Representative IR Spectra ......................................................................................... 52
CAIRO – University of Alberta 2
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Chemistry 261 W2015 Lecture Notes I
I V . St ruc t ure a nd st e re oc he m ist ry of a lk a ne s ...................................... 5 5
Alkanes ...................................................................................................................... 55
Classification of alkanes ............................................................................................ 55
Alkyl Groups .............................................................................................................. 57
Naming of Alkanes..................................................................................................... 58
Nomenclature of Alkyl Halides ................................................................................... 59
Nomenclature of Alcohols .......................................................................................... 60
Cycloalkanes ............................................................................................................. 60
Nomenclature of Cycloalkanes .................................................................................. 61
Cis/Trans Isomers...................................................................................................... 61
Nomenclature of Alkenes ........................................................................................... 62
Nomenclature of Alkynes ........................................................................................... 63
Properties of Alkanes................................................................................................. 64
Synthesis of Alkanes ................................................................................................. 66
Conformations of Ethane (CH3CH3) ........................................................................... 66
Conformations of Propane (CH3CH2CH3) .................................................................. 67
Conformations of Butane (CH3CH2CH2CH3) .............................................................. 69
Conformations and Stability of Cycloalkanes ............................................................. 71
Ring Strain ................................................................................................................. 71
Conformation of Cyclopropane .................................................................................. 71
Conformation of Cyclobutane .................................................................................... 72
Conformation of Cyclopentane .................................................................................. 72
Measuring conformational energy.............................................................................. 73
Conformation of Cyclohexane ................................................................................... 74
Conformations of Substituted Cyclohexanes ............................................................. 75
Bicyclic Compounds .................................................................................................. 78
V . T he st udy of c he m ic a l re a c t ions ....................................................... 8 0
General Types of Organic Reactions ......................................................................... 80
Why and How do reactions happen? ......................................................................... 80
Reaction Mechanisms ............................................................................................... 81
Types of Bond Cleavage and Bond Formation .......................................................... 81
Reaction Equilibria and Rates ................................................................................... 82
Reaction Thermodynamics ........................................................................................ 82
Reaction Kinetics ....................................................................................................... 84
Radical Generation .................................................................................................... 87
Reactions of Radicals – General Types..................................................................... 87
Radical Halogenation of Alkanes – Chain Reactions ................................................. 88
Reactive intermediates .............................................................................................. 92
V I . St e re oc he m ist ry ............................................................................... 9 3
Designation of Double Bond Stereochemistry ........................................................... 93
E/Z Nomenclature of Alkenes .................................................................................... 93
Enantiomers .............................................................................................................. 95
Examples of enantiomers. ......................................................................................... 96
Chirality ...................................................................................................................... 97
Specific Rotation ........................................................................................................ 98
R/S Nomenclature of Stereogenic Centers ................................................................ 99
CAIRO – University of Alberta 3
Downloaded by Randy Davila ()
Organic Chemistry - Lecture notes - Chem261 Notes
Organic Chemistry (University of Alberta)
StuDocu is not sponsored or endorsed by any college or university
Downloaded by Randy Davila ()
, lOMoARcPSD|3123532
Chemistry 261 W2015 Lecture Notes I
CH EM 2 6 1 – I nt roduc t ory Orga nic Che m ist ry I
Cla ss N ot e s
Instructor: Christopher Cairo
University of Alberta
Department of Chemistry
CAIRO – University of Alberta 1
Downloaded by Randy Davila ()
, lOMoARcPSD|3123532
Chemistry 261 W2015 Lecture Notes I
Table of Contents
I . I nt roduc t ion a nd re vie w ....................................................................... 6
Organic Chemistry ....................................................................................................... 6
Atomic Structure - The Atomic Model .......................................................................... 7
Atomic Structure – Orbitals .......................................................................................... 7
Formal Charge ........................................................................................................... 11
Resonance ................................................................................................................ 13
Resonance Forms ..................................................................................................... 13
Formal Charges in Resonance Forms ....................................................................... 15
Some notes on Drawing Organic Structures: ............................................................. 11
Acids and Bases - Brønsted-Lowry (BL) Theory ........................................................ 16
Prediction of Direction of Acid-Base Reactions From pKa’s ....................................... 18
Acids and Bases in Aqueous Media .......................................................................... 19
Prediction of Acid Strength – Factors Influencing Acidity........................................... 21
Inductive effects ......................................................................................................... 22
Atom hybridization ..................................................................................................... 23
Acids and Bases - Lewis Definition ............................................................................ 23
I I . St ruc t ure a nd prope rt ie s of orga nic m ole c ule s ................................ 2 5
Chemical Bonding...................................................................................................... 25
Rules for forming Molecular Orbitals (MO) ................................................................ 29
Hybridization of Orbitals............................................................................................. 30
Structure of Ethane - CH3CH3 .................................................................................... 31
Structure of Ethylene (CH2=CH2) ............................................................................... 31
Structure of Acetylene (HCCH) ................................................................................ 33
Effect of Hybridization on Bond Lengths and Strengths............................................. 34
Hybridization of Nitrogen, Oxygen and Boron ............................................................ 34
VSEPR Model ............................................................................................................ 37
Physical Properties of Organic Molecules ................................................................. 37
Important Intermolecular Interactions ........................................................................ 37
Influence of Intermolecular Interactions on Physical Properties ................................ 39
Water solubility – trends. ........................................................................................... 41
Functional Groups ..................................................................................................... 42
Summary of Common Functional Groups .................................................................. 42
Alkyl Groups .............................................................................................................. 44
R groups .................................................................................................................... 44
Further Classification of Functional Groups Based on Degree of Substitution .......... 44
I I I . I nfra re d Spe c t rosc opy ...................................................................... 4 6
Absorption Spectroscopy ........................................................................................... 46
Infrared (IR) Spectroscopy ......................................................................................... 47
General IR Absorption Trends ................................................................................... 48
Spectral Regions ....................................................................................................... 48
Important Absorptions................................................................................................ 48
Effect of Structure on Carbonyl Stretching Absorption............................................... 49
Representative IR Spectra ......................................................................................... 52
CAIRO – University of Alberta 2
Downloaded by Randy Davila ()
, lOMoARcPSD|3123532
Chemistry 261 W2015 Lecture Notes I
I V . St ruc t ure a nd st e re oc he m ist ry of a lk a ne s ...................................... 5 5
Alkanes ...................................................................................................................... 55
Classification of alkanes ............................................................................................ 55
Alkyl Groups .............................................................................................................. 57
Naming of Alkanes..................................................................................................... 58
Nomenclature of Alkyl Halides ................................................................................... 59
Nomenclature of Alcohols .......................................................................................... 60
Cycloalkanes ............................................................................................................. 60
Nomenclature of Cycloalkanes .................................................................................. 61
Cis/Trans Isomers...................................................................................................... 61
Nomenclature of Alkenes ........................................................................................... 62
Nomenclature of Alkynes ........................................................................................... 63
Properties of Alkanes................................................................................................. 64
Synthesis of Alkanes ................................................................................................. 66
Conformations of Ethane (CH3CH3) ........................................................................... 66
Conformations of Propane (CH3CH2CH3) .................................................................. 67
Conformations of Butane (CH3CH2CH2CH3) .............................................................. 69
Conformations and Stability of Cycloalkanes ............................................................. 71
Ring Strain ................................................................................................................. 71
Conformation of Cyclopropane .................................................................................. 71
Conformation of Cyclobutane .................................................................................... 72
Conformation of Cyclopentane .................................................................................. 72
Measuring conformational energy.............................................................................. 73
Conformation of Cyclohexane ................................................................................... 74
Conformations of Substituted Cyclohexanes ............................................................. 75
Bicyclic Compounds .................................................................................................. 78
V . T he st udy of c he m ic a l re a c t ions ....................................................... 8 0
General Types of Organic Reactions ......................................................................... 80
Why and How do reactions happen? ......................................................................... 80
Reaction Mechanisms ............................................................................................... 81
Types of Bond Cleavage and Bond Formation .......................................................... 81
Reaction Equilibria and Rates ................................................................................... 82
Reaction Thermodynamics ........................................................................................ 82
Reaction Kinetics ....................................................................................................... 84
Radical Generation .................................................................................................... 87
Reactions of Radicals – General Types..................................................................... 87
Radical Halogenation of Alkanes – Chain Reactions ................................................. 88
Reactive intermediates .............................................................................................. 92
V I . St e re oc he m ist ry ............................................................................... 9 3
Designation of Double Bond Stereochemistry ........................................................... 93
E/Z Nomenclature of Alkenes .................................................................................... 93
Enantiomers .............................................................................................................. 95
Examples of enantiomers. ......................................................................................... 96
Chirality ...................................................................................................................... 97
Specific Rotation ........................................................................................................ 98
R/S Nomenclature of Stereogenic Centers ................................................................ 99
CAIRO – University of Alberta 3
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