11-1

Principles and Applications ofInorganic, Organic, and Biological

ChemistryDenniston, Topping, and Caret

4th ed

Chapter 11

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Power Point to Accompany

11-2

Organic Chemistry-HistoryHistorically - compounds from living

systems (plants and animals)A “vital force”, ie. life was thought to be

necessary to make organic chemicals.In 1828 Wohler synthesized urea from

purely inorganic chemicals. Urea, found in urine, was definitely an

organic compound!

CO

NH2 NH2KCNO + NH4Cl + KClurea

11-3

Modern Organic Chemistry

The Study of Carbon Compounds

(some exceptions: for example carbonates, carbon dioxide, etc.)

Biochemistry is now the field that studies chemicals of life.

11-4

Examples of Organic ChemicalsFoods

Carbohydrates

Fats

Proteins

Clothing

silk, linen, wool,

cotton, Dacron,

Nylon, Orlon,

etc.

Plastics

Pharmaceuticals

Detergents and Soaps

Pesticides

Gasoline and oils

Water purification

11-5

11.1 Why is Carbon Unique?

1. Forms four covalent bonds

2. Bonds covalently to: H, O, N, P, S, and all other nonmetals (except noble gases)

3. Carbon atoms join to form:

a. Chains and b. Rings

CH3CH2CH2CH3CH2 CH2

CH2

CH2

CH2

11-6

Why is carbon unique?: 2

4. Carbon can form multiple bonds to itself, oxygen, and nitrogen.

CH2 O

CH2 NH

CH2 CH2

CH CH

CH N

double bonds

triple bonds

11-7

Why is Carbon Unique?: 3

4. Many carbon compounds exist in the form of isomers.

Isomers are compounds with the same molecular formula but different structures.

An isomer example: A, B, and C all are C4H10 but have different structures. See the next slide!

11-8

Why is Carbon Unique?: 3bIsomer Examples. All C4H8

CH2

CH2 CH2

CH2

CH3CH2CH CH2

CH3CH CH CH3

A

B

C

11-9

Organic vs Inorganic: DifferencesOrganic Inorganic

Bonding Covalent Ionic

Physical State

(room temp)

Gas/liquid common

Solids common

Melting points Tend to be low Tend to be very high

Sol. In water Tend to be insoluble

Much higher percent soluble

Conductivity Nonconductors Conduct in soln. and molten

11-10

Families of Compounds: Hydrocarbons

Hydrocarbons contain only carbon and hydrogen.

They are nonpolar molecules and consequently are not soluble in water but are soluble in typical nonpolar organic solvents like toluene or pentane.

Hydrocarbons are constructed of chains or rings of carbon atoms with sufficient hydrogens to fulfill carbons need for four bonds.

11-11

Hydrocarbons

Aliphatics Aromatics

Structures Based On:Chains and Benzene ring

nonbenzenoid

rings

11-12

Hydrocarbons

Aliphatics Aromatics

Alkanes and cycloalkanes

Alkenes and cycloalkenes

Alkynes and cycloalkynes

11-13

Functional groups

Alkanes are compounds that contain only carbon-carbon and carbon-hydrogen single bonds.

For example:

CH2

CH2CH2

CH2

CH2 CH2

CH3 CH3

CH3 CH2 CH3

cyclohexane-a ring alkane

propane-burned in a barbecue grill

ethane

11-14

Functional groups-2

alkenes have a carbon-carbon double bond

alkynes have a carbon-carbon triple bond

CH2 CH2

CH3

CH2CH2

C C

C C

CH2

CH2

CH2CH2

CH2CH2

CH2CH2

H H

H

H

CH2OH

CH CH

female silkworm mothsex attractant

ethene: basis of polyethylene plastics

acetylene-welding gasin oxyacetylene torch

11-15

Functional groups-3alcohols have the general formula:

ROH (R is a carbon group)

ethers have the general formulas:

R-O-R, Ar-O-R, Ar-O-ArAr is also a carbon group but is “aromatic”

phenols have the general formula:

Ar-OH (aromatic only!)

OH

CH3CH2 OH

CH3CH2O CH2CH3

ethanol, drinking alcohol

phenol-an early topicalanesthetic

diethyl ether, a generalanesthetic

aromatic ring

11-16

Functional groups-4aldehydes have the general formula

R1 may be H or any carbon group

ketones have the general formula

neither R1 nor R2 can be H

aldehyde carbonyl

ketone carbonyl

R1 C H

O

R1 C R2

O

H CO

CHOH

CH2OPO32-

CH3C CH2

OCO

Oacetoacetate ion, productof fat metabolism

glyceraldehyde-3-phosphatefrom glucose metabolism

11-17

Functional groups-5carboxylic acids have the general formula

R1 may be carbon or Hesters have the general formula

R1 may be carbon or H but R2 cannot be H or it would be an acid!

ester carbonyl

acid groups

R1 C OHO

R1 CO

OR2

OH

C O

O

CH3

CH2 C

O

OH

C

CH2

OH

C OH

O

CO2H

citric acid, found in fruits

condensedformula

methyl salicylateoil of wintergreen

11-18

Functional groups-6acid chlorides have the general formula

R1 is usually carbon

anhydrides have the general formula

R1 usually is the same as R2 and neither is H

R1 C ClO

R1 C O C R2

O O

ClCO

CH2CH2CH2CH2CO

Cl

CH3CO

OCO

CH3

pivaloyl chloride- used to make nylon

acetic anhydride-used to transferan acetyl group

11-19

Functional groups-7amines have one of these general formulas

R groups may be alkyl or aromatic

amides have the general formula

All Rs may be carbon or H

amine nitrogens

amide bond

R1 NH2 R1 NHR2

R1 NR2

R3

R1 C

O

NR2

R3

N

CH2 CH

NH2

C

O

OH

N C CH3

OH

O

Tryptophan- an essential aminoacid

acetaminophen-theanalgesic found inTylenol (Reg)

11-20

Functional Groups-8thiols (mercaptans) have the general formula

R1 is any carbon group

disulfides have the general formula

R is any carbon groupRs may be different

R1 SH

R S S R

H CNH2

CH2 SHCOOH

H C

NH2

CH2 S

COOH

HC

NH2

CH2S

COOH

cysteine, anamino acidfound incystine-an amino acid

important in3-D structure of proteins.

11-21

Test: Identify the groups 1-91 an amine

2 a carboxylic acid

3 an ester

4 an alkene

5 an aldehyde

6 an alcohol

7 a ketone

8 a thiol

9 an anhydride

NH2

CH C

O

CH3 OH CO

O

CH3

CH3

CH2CHCHCH2

OHCH2

CH

CHCH

CH

C

O

OH

OH

OH

OH

H

CO

CH3

CH2

CH2

CH2 SH

CH3 C O

O

C CH3

O9.

8.

7. 6.

5.4.

3.2.

1.

11-22

11.2 Alkanes, CnH2n+2The title shows the general formula for a

chain alkane.

The first ten alkanes are:

methane CH4 hexane C6H12

ethane C2H6 heptane C7H16

propane C3H8 octane C8H18

butane C4H10 nonane C9H20

pentane C5H12 decane C10 H22

11-23

Lewis vs Condensed Formulas

The Lewis dot and condensed formulas for methane.

The Lewis dot and condensed formulas for ethane .

CH

HHH

CH

CHH

HH

HCH3CH3

CH4

11-24

Drawing Methane and Ethane

C

H

HH

C

H

HH

109.5 o

Staggered form of ethane

H

H

HH

in plane

in front of plane

behind plane

11-25

Lewis vs Condensed Formulas-2Lewis dot vs condensed formulas: propane.

Terminal carbons condense to CH3 with the

hydrogens usually to the right of the carbon. Interior carbons condense to CH2 .

C C C HHH

H

H

H

H

HCH2CH3 CH3

11-26

Lewis vs Condensed Formulas-3A branch or substituent on a chain may be condensed into the chain usually after the carbon from which it branches.

CH3CH(CH3)CHClCH2CH3

H C C C C CH

H H

H

Cl

H

HH

H

H

C HHH

11-27

IUPAC NamesThe IUPAC (International Union of Pure

and Applied Chemistry) is responsible for chemistry names.

Before learning the IUPAC rules for naming alkanes, the names and structures of eight alkyl groups must be learned.

These alkyl groups are historical names accepted by the IUPAC and integrated into modern nomenclature.

11-28

Alkyl Groups

An alkyl group is an alkane with one hydrogen atom removed. It is named by replacing the ane of the alkane name with -yl.

Methane becomes a methyl group.

or CH3H C

H

H

H

H C

H

H

11-29

Alkyl Groups-2

All six hydrogens on ethane are equivalent. Removing one H generates the ethyl group.

CH

CHH

HH

H

CH3CH2

CH3CH2

C2H5

11-30

Alkyl Groups-3Propane: removal of a hydrogen generates two different propyl groups depending on whether an end or center H is removed.

n-propyl isopropyl

CH3CH CH3CH3CH2CH2

CH3 CH2 CH3

11-31

Alkyl Groups-4a

n-butane gives two butyl groups depending on whether an end (1o) or interior (2o) H is removed.

sec-butyln-butyl

CH3 CH2 CH2 CH3

CH3 CH CH2 CH3CH3 CH2 CH2 CH2

11-32

Alkyl Groups-4bIsobutane gives two butyl groups

depending on whether a 10 or 30 H is removed.

isobutyl t-butyl

1o C

3o C

CH3 CH CH3

CH3

CH3 CH CH2

CH3

CH3 C CH3

CH3

11-33

IUPAC Names for Alkanes-1

1. The base or parent name for an alkane is determined by the longest chain of carbon atoms in the formula. Note: the longest chain may bend and twist. It is seldom horizontal!

Any carbon groups not part of the base chain are called branches or substituents.

These carbon groups are also called alkyl groups.

11-34

IUPAC Names for Alkanes-1aRules 1 applied. Find the longest chain in each molecule. (Click for answer.)

A=7 B=8

CH3

CH2

CH2CH2CH CH2CH3

CH3

CH3CH

CH2

CH3

CH2CH

CH2CH2

CH2

CH3

CH3

A

B

11-35

IUPAC Names for Alkanes-22. Number the carbon atoms in the chain

starting from the end with the first branch. If both branches are equally from the ends, continue until a point of difference occurs.

11-36

IUPAC Names for Alkanes-2a

Left: first branch is on carbon 3.Right: first branch is on carbon 3 (From

top) not carbon 4 (If from right).

123

45

6

7

1

2

3 4 5

6 7 8

this branch would be on C-4if you started at correct C-8.

Number the carbon atoms correctly.

CH3

CH2

CH2CH2CH CH2CH3

CH3

CH3CH

CH2

CH3

CH2CH

CH2CH2

CH2

CH3

CH3

11-37

IUPAC Names for Alkanes-33. Prefix the branches/substituents

in alphabetical order before the base/stem name (longest chain). Halogens usually come first.

Indicate the position of the branch on the main chain by prefixing its name with the carbon number to which it is attached. Separate numbers and letters with a hyphen.

11-38

IUPAC Names for Alkanes-3a

Name

4-ethyl-2-methylhexane

CH3CH2CH CH2CH CH3

CH3CH2

CH3

11-39

IUPAC Names for Alkanes-3b

Hyphenated and number prefixes are not considered when alphabetizing groups.

Name the compound below.

5-sec-butyl-4-isopropylnonane

CH CHCH3

CH3 CH2 CH2 CH3

CHCHCH3

CH2 CH3

CH2 CH2 CH2 CH3

11-40

IUPAC Names for Alkanes-4

When a branch/substituent occurs more than once, prefix the name with di, tri, tetra,etc. Then prefix the number to the name with a separate number for each occurance. Separate numbers with commas.

eg. 3,4-dimethyl or 4,4,6-triethyl

11-41

IUPAC Names for Alkanes-4a

5-ethyl-2,3-dimethylheptaneethyl>dimethyl

CH3CHCH3 CH CH2CH

CH2CH3

CH3

CH2CH3

Name

11-42

Test: IUPAC Names

6-ethyl-6-isobutyl-3,3-dimethyldecane

CH3CCH3

CH2

CH3

CH2CH2C CH2CH3

CH2

CH CH3CH3

CH2CH2CH2CH3

Name

11-43

Constitutional/Structural Isomers

Constitutional/Structural Isomers differ in how atoms are connected. The two isomers of butane are shown below. The carbon atoms are connected in different patterns.

butaneBp –0.4 oCMp –139 oC

IsobutaneBp –12 oCMp –145 oC

CH3 CH2 CH2 CH3 CH3 CH CH3

CH3

11-44

11.3 CycloalkanesCycloalkanes have two less hydrogens than

the corresponding chain alkane.

Hexane=C6H14; cyclohexane=C6H12

To name cycloalkanes, prefix cyclo to the name of the corresponding alkane.

Place substituents in alphabetical order before the base name as for alkanes.

For multiple substituents, use the lowest possible set of numbers. A single substituent requires no number.

11-45

Cycloalkanes-cont.

Cyclopropane cyclohexane

C C

C

H

H

HH

H

H

CC

C

C C

CH

H H

H

H

HH

H

H H

H H

or

CC

C

C C

CH

Cl H

CH3

H

HH

H

H H

H H

CH3

Clor

1-chloro-3-methyl-cyclohexane

11-46

Cis-trans Isomers in CycloalkanesTwo groups may be on the same side (cis) of

the imagined plane of the cycloring or they may be on the opposite side (trans). The two isomers are referred to geometric or cis-trans isomers. E. g.

cis-1-chloro-3-ethylcyclohexane

trans-1-chloro-3-ethylcyclohexaneCH3

Cl

CH3

Cl

ClCl

Cl

Cl cis-1,4-dichlorolcyclohexane

trans-1,4-dichlorocyclohexane

11-47

11.4 Conformations of AlkanesConformations differ only in rotation about

carbon-carbon single bonds. Two conformations of butane are shown below. The first (staggered form) is more stable because it allows hydrogens to be farther apart and thus the atoms are less crowded.

Insert Fig 11.6

11-48

Two conformations of CyclohexaneChair form Boat form

(more stable)A

E

E

A

AE

E A

E

E

A

A

H HH H

H H

H

H H

H

HH

E=equitorialA=axial

11-49

11.5 Reactions of AlkanesAll alkanes undergo:

Combustion to carbon dioxide and water

Halogenation to haloalkanes

2 C2H6 + 7 O2 4 CO2 + 6 H2O CH3CH3

+Cl2heat orlight CH3CH2Cl +HCl

HH +Br2

heat orlight +HBr

BrH

11-50

Organic IntroductionSaturated Hydrocarbons

The End