Chapter 15 Organic Chemistry. “Organic chemistry …is enough to drive one mad. It gives me the...

Chapter 15

Organic ChemistryOrganic Chemistry

Organic Chemistry

““Organic chemistry …is enough to drive one mad. Organic chemistry …is enough to drive one mad. It gives me the impression of a primeval forest, It gives me the impression of a primeval forest, full of the most remarkable things, a monstrous full of the most remarkable things, a monstrous and boundless thicket, with no way of escape, and boundless thicket, with no way of escape, into which one may well dread to enter.”into which one may well dread to enter.”

-Friedrich W-Friedrich Wöhleröhler

Which of these are “organic”?

CHCH33CHCH22CHCH22OHOH

NaCNNaCN

CHCH33COOHCOOH

CHCH33(CH(CH22))1616COOHCOOH

HCHCCHCH

CaCOCaCO33

CHCH33CH=CHCH=CH22

What is special about carbon?

Carbon

1. Electron configuration, 1. Electron configuration, electonegativity, and covalent bondingelectonegativity, and covalent bonding

2. Bond properties, catenation, and 2. Bond properties, catenation, and molecular shapemolecular shape

3. Molecular stability3. Molecular stability

Hydrocarbons““Aliphatic”Aliphatic”

AlkanesAlkanes Alkenes Alkenes Alkynes Alkynes

““Aromatic”Aromatic”

C

H

HH HC

H

H

CH

CH

H

HC C HH

Single, double, and triple bonds

C HH

H

H

CH

H

C H

H

CH C H

CH4 C2H4 C2H2

Alkanes, CnH2n+2

““Saturated”Saturated”

C9H20

22_492

C

sp3

sp3sp3

sp3

H1s

H1s

H1s

H1s

Single Bonds - sp3 (tetrahedral)

109.5°

22_494

(a) (b)

Staggered Conformations

22_494

(a) (b)

22_502

H

H

H H

H

H

CC

Single bonds - unrestricted rotation

Structures & Rotation22_493

C

H

H

C

H

H

H H

(a) (b)

Ethane

C2H6

CH3CH3

22_493

C

H

H

C

H

H

H H

(a) (b)

Staggered

Eclipsed

Conformations

Different spatial arrangements generated by Different spatial arrangements generated by rotation around a single bondrotation around a single bond

22_495

(a)

(b)

Constitutional (structural) isomers

Naming

1.1. Longest C-C chain:Longest C-C chain: root nameroot name

2.Suffix:2.Suffix: compound typecompound type

3.3. Prefix for rings:Prefix for rings: “cyclo” “cyclo”

4.4. Branches:Branches: root + “yl”root + “yl”

alphabeticalalphabetical

numberednumbered

Alkane examples

© Mc-Graw-Hill Companies, Inc. All rights reserved.

22_496

CH3 CH2CH2CH2CH3

n-Pentane

22_496

CH3 CH2CH2CH2CH3

n-Pentane

Physical Properties

Straight:Straight: lower melting points, higher boiling pointslower melting points, higher boiling pointsBranched:Branched: higher melting points, lower boiling pointshigher melting points, lower boiling points

22_499

C C

C

109.5

60

No "head-on"overlap of atomic orbitals

(b)(a)

Ring strain - cyclopropane

22_500

Boat

(b)

These two Hatoms repeleach other

Chair

(a)

Conformations of cyclohexane

Enantiomers

22_501

H1s

sp2

sp2

sp2

sp2

H1s

2p

C C

sp2

sp2

Alkenes, CnH2n - sp2

““Unsaturated”Unsaturated”

Geometric Isomers

Light energy temporarily excites bond electrons

Bond breaks - allows rotation

22_504

2p

2pH1s

H

sp

2p

2p

C

sp 2p

2p

2p

C H

H1s

2p

sp

Alkynes, CnH2n-2 - sp

““Unsaturated”Unsaturated”

Aromatic - Benzene derivatives

Delocalized (conjugated) Delocalized (conjugated) electron cloud electron cloud

Free-Radical Substitution Reactions

Alkanes:Alkanes:

HClCCl ClCHCl 4hυ

23

HBrBrCHCH BrCHCH 23hυ

233

HBrCBrCHCH BrCHCHCH

CH CH

33hυ

233

33

Functional Groups - Reactive Sites

Important Reactions 1 - Substitution

C bonded to same number of atomsC bonded to same number of atoms

|R— C — X |

:Y

|R— C — Y |

:X

Important Reactions 2 - Addition

Two Two bonds from one bonds from one bond and one bond and one bond bond

R— C — C — R X—Y

X Y | |R— C — C — R | |

Important Reactions 3 - Elimination

Elimination of small, stable molecule + entropyElimination of small, stable molecule + entropy

R— C — C — R X—Y

X Y | |R— C — C — R | |

Oxidation-reduction

Oxidation:Oxidation:– More bonds to OMore bonds to O– Less bonds to HLess bonds to H

Reduction:Reduction:– Less bonds to OLess bonds to O– More bonds to HMore bonds to H

OR— C H

| R— C — OH |

OR— C OH

| R— C —H |

Functional Groups with Single Bonds

Alcohols & EthersAlcohols & Ethers

HaloalkanesHaloalkanes

AminesAmines

R—O —H

R—X: X = halogen

R— N — |

R—O —R

Alcohol Reactions

EliminationElimination– Elimination of HElimination of H22O in acidO in acid

DehydrationDehydration to C=C to C=C– Elimination of 2 H w/ strong ox.agentElimination of 2 H w/ strong ox.agent

Oxidation Oxidation to C=Oto C=O

SubstitutionSubstitution– Single bonded productsSingle bonded products– ““Reactive” C bonded to electronegative atomReactive” C bonded to electronegative atom

Haloalkane Reactions

Elimination Elimination of HX in very strong baseof HX in very strong base

C=C productC=C product

Substitution Substitution in basein base– Single bonded productsSingle bonded products

——OH, —OR, —CN, —SH, —NHOH, —OR, —CN, —SH, —NH22, …, …

– ““Reactive” C bonded to electronegative atomReactive” C bonded to electronegative atom

Amine ReactionsSubstitutionSubstitution– Single bonded productsSingle bonded products– Lone pair on N attacks Lone pair on N attacks + on another molecule+ on another molecule

|2R— C — NH2 |

R’—C H2— Y

|R— C — NHR’ |

| + R— C — NH3Cl |

Functional Groups with Double Bonds

AlkenesAlkenes

AldehydesAldehydes

KetonesKetones

Carboxylic Carboxylic AcidsAcids

e- rich

R— C — C — R

OR— C H

OR— C OH

e- rich

e- rich

Aromatic - Substitution Reactions

Delocalized electrons stabilize ring

Charge Distribution & Reactivity

Can undergo substitution or oxidation-reductionCan undergo substitution or oxidation-reduction

Oxidation of aldehydes to acids

Substitution

Z—Y

O—Z | R— C — OH | Y

OR— C OH

OR— C Y

Z—OH

1. Addition

2. Elimination

Substitution

dehydration

dehydration

dehydration

Substitution of —OH by N in amines

Functional Groups with Triple Bonds

AlkynesAlkynes

NitrilesNitriles

e- rich

R— C — C — R

R— C — N:e- rich

Reactions: addition

Formation increases C chain by 1

Reactions: subsitution/hydrolysis, reduction, …

Types of polymers

Addition Polymerization:Addition Polymerization:

monomers “add together” to form the polymer, monomers “add together” to form the polymer, with no other products. (Teflon)with no other products. (Teflon)

Condensation Polymerization:Condensation Polymerization:

A small molecule, such as water, is formed for A small molecule, such as water, is formed for each extension of the polymer chain. (Nylon)each extension of the polymer chain. (Nylon)

Biological Polymers

Carbohydrates, saccharides, polysaccharidesCarbohydrates, saccharides, polysaccharides

Amino acids, peptides, proteinsAmino acids, peptides, proteins

Fatty acids, lipids, fats, oils, waxes, steroids, Fatty acids, lipids, fats, oils, waxes, steroids, phospholipidsphospholipids

Nucleotides, nucleic acidsNucleotides, nucleic acids

Saccharides/Carbohydrates

C

C

C

C

C

CH2OH

OH

OH

HO

OH

OH

H

H

H

H

C

C

C

C

C

CH2OH

O

OH

HO

OH

OH

H

H

H

H

H C

C

C

C

C

CH2OH

O

OH

HO

OH

OH

H

H

H

H

H

O H

H

H

HH

OH

OH

CH2OH

OH

O

HH

H

HH

OH

OH

CH2OH

OH

D-glucose -D-glucopyranose -D-glucopyranose

O

H

H

HH

HOH

CH2OH

OH

O

HH

H

HH

OH

OH

CH2OH

O

O

H

H

HH

H

OH

CH2OH

OH

O

HH

H

HH

OH

OH

CH2OH

O

-1-4-glycosidic bond

-1-4-glycosidic bond

Glycosidic linkages (dehydration)

Disaccharides

Polysaccharides

AmyloseAmylose

AmylopectinAmylopectin

StarchStarch

GlycogenGlycogen

CelluloseCellulose

23_528 Mirror

Amino acids

HH | O N—C—CH | OH R

Amine Acid

-carbon

Amide Linkage (“peptide bond”)

H O H HH | || | | O N—C— C — N — C — C +H2OH | | OH R R’

peptide bond (dehydration)

23_519

Oxygen

R

R

R

R

R

R

R

R

R

R

R

Hydrogenbond

Carbon

Nitrogen

Hydrogen

Hydrogenbonding

Levels of Structure 1

23_520

CHC

O

H

N

CH

R

N

HHC

R

R

CO

NCH

H

R O

CN

HC

R

C

OH

CH

R

C

O

H

N

N

HHC

R

CO

NCH

H

RO

CN

HC

R

C

OH

CH

R

C

O

H

N

N

HHC

HC

C

O


23_527

OH

R1

CH H

CH C

O

ON H

H

C

O

CH

N

HR2

CO

C

H

R3N

COC

H

R4

N

H

C

O

C

R5N

H

H

Zn2+

Bulky side chainsfit in easily

Bond brokenby enzyme

Hydrophobicpocket for R group

23_542

(–)

(–)

(–)(–)

(–)

(–)

(–)

(–)(–)

(–)

(–)

(–)

(–)

Nonpolartail

Polarhead

23_544

CH

CH2

CH2

O

O

C

C

O

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH3

O

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH3

P

O

OCH2NCH2CH3+

CH3

CH3 O–

O

Polar head

Nonpolar tails

23_539

G CT A

A

A

T

T

C

A TC G

T A

GG C

T AC G

A

A TG C

C GT A

A

ATCG

A TAT

C G

T

TG C

C GT A

A

TC G

NewNew

A

T

TG C

C GT A

A

A TG C

T A

A TC G

A TOld New New Old

Old Old

23_540

Nucleus

DNA

RNA

tRNA Aminoacid

+

mRNA

Ribosome movesalong mRNA

Growingpolypeptidechain

RibosomeCompletedprotein

(as specified by mRNA)

+

23_538

A T

T A

G C

A T

C G

A T

AT

GC

CG

T A

T A

G C

N

N HN

H

HN

NH

HO

N

N

CH3

Deoxyribose

Adenine

Thymine

(a)

(b)

O

NN

N

H

H

N

NGuanine

CytosineO

H

H

H

H

N

(c)

H

O

H

Deoxyribose

Deoxyribose

Deoxyribose

N

N H

23_514

1H

3

Li

11

Na

87

Fr

4

Be

12

Mg

88

Ra89

Ac104

Unq105

Unp106

Unh107

Uns108

Uno109

Une110

Uun111

Uuu

5

B

13

Al

6

C

14

Si

7

N

15

P

8

O

16

S

9

F

17

Cl

10

Ne

18

Ar

37

Rb38

Sr39

Y40

Zr41

Nb42

Mo43

Tc44

Ru45

Rh46

Pd47

Ag48

Cd49

In50

Sn51

Sb52

Te53

I54

Xe

55

Cs56

Ba57

La72

Hf73

Ta74

W75

Re76

Os77

Ir78

Pt79

Au80

Hg81

Tl82

Pb83

Bi84

Po85

At86

Rn

2

He

58

Ce

90

Th

59

Pr

91

Pa

60

Nd

92

U

61

Pm

93

Np

62

Sm

94

Pu

63

Eu

95

Am

64

Gd

96

Cm

65

Tb

97

Bk

66

Dy

98

Cf

67

Ho

99

Es

68

Er

100

Fm

69

Tm

101

Md

70

Yb

102

No

71

Lu

103

Lr

1A

2A 3A 4A 5A 6A 7A

8A

19

K20

Ca21

Sc22

Ti23

V24

Cr25

Mn26

Fe27

Co28

Ni29

Cu30

Zn31

Ga32

Ge33

As35

Br36

Kr34

Se

Chapter 15 Organic Chemistry. “Organic chemistry …is enough to drive one mad. It gives me the...

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