Brdy 6Ed Ch23 OrganicPolymersAndBiochemicals

8/9/2019 Brdy 6Ed Ch23 OrganicPolymersAndBiochemicals

1/124

Chapter 23:

Organic Chemistry,Polymers, and Biochemicals

Chemistry: The Molecular Natureof Matter, 6E

Jespersen/Brady/Hyslop1


2/124

Jespersen/Brady/Hyslop Chemistry: The Molecular Nature of Matter, 6E

Carbon ChemistryBonding

Strong covalent bonding to itself and to other non-metal elementsCapable of forming extremely long carbon-carbonchains

Multiple arrangements ofidentical molecular formulaslead to numerous isomers.

2


3/124


Structural Formula RepresentationsLewis Structure of Pentane

Condensed Structural FormulaCH3CH2CH2CH2CH3 pentane

3

C

C

C C

C

HH

H

H

H

H

H

H

H

H

H H


4/124


Structural Formula Representations

Lewis Structure of Pentan-1-ol

Condensed Structural FormulaCH3CH2CH2CH2CH2OH 1-pentan ol

4


5/124

Jespersen/Brady/Hyslop Chemistry: The Molecular Nature of Matter, 6E 5

Chiral Isomers of CarbonChirality exists when carbon has fourunique constituents bond to itself

|||||

Non-superimposable mirror images

3


6/124


Chiral Isomers of Butan-2-ol

6


7/124


Abbreviated or Bond-Line Structure

Carbon atoms occur at intersection butno symbol used

CH3-CH2-CH3 would appear as:

Non-carbon atoms would appear assymbols

CH3-CH2-CH2-OH would appear as:

7


8/124



Open-Chain CompoundsExamples


9/124


Abbreviated or Bond-Line Structure ofRing Compounds


10/124



Heterocyclic Compounds


11/124


Learning Check 1. Draw at least two geometric isomers of C 4H10

using abbreviated structures.

-Draw the four carbon chain first-Now rearrange CH 3 groups

11


12/124


Your Turn!When a chemical formula is written in the followingform, CH 3CH2CH2COOH, the representation isknown as:

A. an abbreviated structure

B. a Lewis dot structure

C. a condensed formula

D. an optical isomer

12


13/124


Functional Groups in OrganicOrganic families can be defined by functionalgroups.

Frequently use R as a place holder foralkane-like hydrocarbon groups

R-OH alcohol

R-COOH organic acidR-O-R ether

13


14/124


Functional Groups in Organic

14


15/124


Learning Check

1.Write the abbreviated structure for benzoicacid.

2. What family does C 6H5NH 2 belong to?

1.2. amine family

15


16/124


17/124


HydrocarbonsHydrocarbon compounds only contain C and H

Alkanes C nH2n+2 CH3CH2CH3 propane

Alkenes C nH2n CH3CHCH2 propene

Alkynes C nH2n-2 CH3CCH propyne

Aromatic C 6H6 benzeneCharacterized by cyclic delocalized bonding

17


18/124


Hydrocarbons Alkanes are defined as saturated compounds.

All singles bond to carbonCannot add more hydrogen atoms

Alkenes and alkynes are unsaturatedcompounds.

Alkenes have double bonds and H atoms can beadded to the double bond to create a saturatedcompound.

Alkynes have triple bonds and H atoms can beadded to create a saturated compound.CH2=CHCH3 + H 2 CH3CH2CH3

18

Pt uuuur


19/124


Aromaticity- Characterized by conjugated bonds in a ring such

as benzene.- electrons are delocalized over the ring- Leads to greater stability than expected- Properties are different than those of other

hydrocarbon families- Polycyclic examples:

19


20/124


Hydrocarbon NomenclatureRules for naming alkanes

Established by IUPAC

1. Name ends in -ane 2. Complete name uses that of parent

compound with constituent groups added.

3. Parent is longest continuous carbon chain.4. Name of longest chain based on the number

of carbons.5. Carbon atoms are numbered starting at theend that gives the lowest number for the

first branch.20


21/124


Straight Chained Alkanes

21


22/124


Alkyl Groups Alkane type groups added to parent chain areknown as alkyl groups. Consist of alkane,minus one H atom. Name always ends in - ylExampleCH4 : now remove one H which yields CH 3

Naming of CH 3Start with parent name, which is methane

Drop ane and add ylSo methane becomes methyl group

22


23/124


24/124


Nomenclature6. Aryl groups names are prefixed to parent

name.7. Multiple aryl groups on a parent are

numbered and named alphabetically.8. When there are multiple identical groups add

di, tri, tetra to the aryl name.9. If multiple, identical aryl groups are attached

to the same carbon repeat the carbon

number.

24


25/124


Examples

What is the name of the compound shown?

1. The longest carbon chain (parent) isfour. Parent name is butane.

2. Start numbering from the left to get thesmallest number for the attached group.

25


26/124


Examples3. The attached alkyl group is a methyl

group.Thus, the correct name is:

2-methylbutane

What is the name of the following compound?

26


27/124


ExamplesThe parent chain contains five carbons.Thus, the parent name is pentane.Number from the left to obtain the smallest numberfor the first alkyl group.

The alkyl groups are at the 2 and 3 positions.The 2 and 3 positions each contain a methyl group.

27


28/124


29/124


ExamplesThe parent chain is six carbons long.The lowest correct numbering of positions isshown below.

There are methyl and ethyl groups attached tocarbon 3.

29


30/124


31/124


Your Turn!What is the correct name for the molecule shownbelow?

A. 3-butylpentaneB. 1,1-diethylpentane

C. 3-ethylheptaneD. 5-ethylheptane

31


32/124


Your Turn!What is the name of the compound shown below?

A. 3-methyl-3-methyloctaneB. 3,3-dimethyloctaneC. 2-ethyl-2-methylheptane

D. 6,6-dimethyloctane

32


33/124


34/124


Alkenes and Alkynes Alkenes contain one or more double bonds

General form: C nH2n Alkynes contain one or more triple bonds

General form: C nH2n-2

Non-polar compounds are not water solubleExamples:

34

2 2


35/124


Alkenes and AlkynesNomenclature

The parent chain must contain the multiple bondeven if it is a smaller chain length than one without

a multiple bondNumber from end that gives the lowest number tothe first carbon of the multiple bondThe number is given as -x- and placed just beforethe ene or yne of the parent name. For example,but-2-ene. The double bond starts on carbon 2 ofthe chain.

35


36/124


Alkene Examples

Start numbering from the left to get the lowestnumber for the first carbon with the double bond

The parent is heptene and the correct namingincluding the double bond location would behep-2-ene

36

lk l


37/124


Alkene Example

The parent chain is four carbons2,3-dimethylbut-2-ene

We would not name this 2-methyl-3-methylbut-

2-ene

37

N i P l


38/124


Naming PolyenesHow do we name compounds such as the following?

This compound contains two double bonds and isknown as a diene

We want the lowest number for the first carbon ofeach of the double bondsStart numbering from the right

38

N i P l


39/124


Naming PolyenesThe correct name would be hex-1,3-diene

Three double bonds would be a triene

hex-1,3,5-triene

39

C li Alk


40/124


Cyclic Alkenes

Number ring to obtain lowest number for firstcarbon of the double bond

40

C li Alk


41/124


Cyclic AlkenesCorrect name is 1,6-dimethylcyclohex-1-ene

Other ring examples

41

Y T !


42/124


Your Turn!What is the correct name for the compound shownbelow?

A. 1,4-dimethylcyclopent-1-eneB. 1,3-dimethylcyclopent-1-ene

C. 1-methyl-4-methylcyclopent-1-eneD. 1,3-dimethylcyclo-1-pentene

42

Your Turn!


43/124


Your Turn!What is the correct structure for 3,3-dimethylpro-1-ene?

A.

B.

C.

D.

43

Geometric Isomers


44/124


Geometric IsomersGroups cannot freely rotate about a double bondTherefore, it is possible to have geometricisomers

Examples:

44

Reactions of Alkene


45/124


Reactions of Alkene Alkenes readily add across the double bondExamples of an addition reaction:

CH2CH2 + H 2 CH3CH3 hydrogenation

CH2CH2 + HCl CH3CH2Cl

CH2CH2 + H 2O CH3CH2OH

CH2CH2 + Cl 2 CH2ClCH2Cl

45

Pt

Aromatic Hydrocarbons


46/124


Aromatic HydrocarbonsThe most common aromatic compound isbenzene and its derivativesRepresentation of bonding

Delocalized bonds create unique stability,called resonance stabilization. The circle in thering represents delocalization.

46

Reactions


47/124


ReactionsSubstitution reactions maintain benzenesresonance structure.

Addition reactions, like those of alkenes, destroyresonance structure

Substitution reaction:

47

Addition Reaction


48/124


Addition Reaction

Notice that you have reduced the doublebonding in the ring and altered the resonancestabilization of the ring

48

L i Ch k


49/124


Learning Check:What product would form if benzene reacted withnitric acid using an appropriate catalyst?

Sulfuric acid is the catalyst

A substitution reaction occurs

49

Your Turn!


50/124


Your Turn!

Which product is most likely formed when sulfuricacid reacts with benzene?

A.

B.

C.

D.50

Organic Compounds Containing Oxygen


51/124


g p g yg

Important functional groups:

51

R

R'

O

R

O

O

R

OH

O

R'

Alcohols and Ethers


52/124


Alcohols and Ethers

Common alcohols: names end in -olCH3OH methanolCH3CH2OH ethanolCH3CH2CH2OH propan-1-ol

If the OH group was attached to the central carbonthen the alcohol would be propan-2-ol

Alcohols form hydrogen bonds, causing their boiling

points to be higher than predicted.

52

Alcohols and Ethers


53/124


Alcohols and Ethers

Primary alcohols:

Secondary alcohols:

Tertiary alcohols:

53


54/124

Reactions of Alcohols


55/124


Alcohols can undergo oxidation to form a varietyof products. Oxidation removes an H atom fromthe alcoholic carbon as well as the H on the O H

group.

Primary alcohols can be oxidized to aldehydesand carboxylic acids

55



56/124


Aldehydes are more readily oxidized thanalcohols

Secondary alcohols can be oxidized to ketones

56



57/124


Ketones are not further oxidizedTertiary alcohols have no H atom on thealcoholic carbon and thus, do not undergooxidation

Alcohols undergo elimination reactions in thepresence of concentrated H 2SO4 forming waterand alkenes

-OH group readily accepts a proton fromsulfuric acid

57

Elimination Reaction


58/124


Dehydration of an alcohol

During the reaction a very unstable carbocationis formed. This ion eliminates a proton to formthe alkene.

58

H 3 C

H 2 C C

H 2 C OH

2 4

H 3 C

H 2C

CH

CH 22

H

H

Substitution Reactions of Alcohols


59/124


Using heat and concentrated HBr, HI, or HCl, ahalogen will replace the OH group

A proton adds to the OH forming OH 2+

Water leaves and the halogen ion attaches to thecarbon site where the OH was attached

59

Aldehydes and Ketones


60/124


Naming AldehydesParent name ends in al , replacing e in the alkanenameThe aldehyde group is always at the end of a chainand numbering starts with that end of the chain

60

Naming Aldehydes


61/124


Number from the Aldehyde end

Do not use -1- for Aldehyde:3-methylpropan-1-al, or 3-methyl-1-propanalwould be wrong

61

Learning Check


62/124


What is the name of the following aldehyde?

4-ethylhexanal

62

Naming Ketones


63/124


Parent name ends in one Parent chain must contain carbonyl groupNumbering so carbonyl carbon has lowestpossible number

4-ethylheptan-3-oneNOT: 4-ethylheptan-5-one

63

Your Turn!


64/124


What is the correct name for the aldehyde shownbelow?

A. 2,4-dimethylpentanal

B. 2,4-dimethyl-1-pentanalC. 2-methyl-4-methylpropanalD. 2,4-dimethyl-5-pentanal

64

Your Turn! - Solution


65/124


Aldehydes are numbered from the aldehyde endof the molecule

There are two identical groups, (methyl) so weuse di in the naming

65

Your Turn!


66/124


What is the correct name for the ketone shownbelow?

A. 4-methyl-3-ethylhexan-2-one

B. 4-ethyl-3-methylhexan-5-oneC. 3-ethyl-4-methylhexan-2-oneD. 3,4-diethylpentan-2-one

66

Your Turn! - Solution


67/124


Number to give lowest number to keto group soyou start from the right

Alkyl groups are ordered alphabetically so ethylcomes before methyl

67

Reactions of Aldehydes and Ketones


68/124


Aldehydes and ketones add hydrogen across theC=O bondProcess is hydrogenation or reduction

68

2

O OH

2

Carboxylic Acids and Esters


69/124


Naming Carboxlic Acids


70/124


Name ends in oic, replacing e in the parentnameNumbering begins with carboxyl group

-COOH or -CO 2H is the condensed formCH3COOH is ethanoic acid (acetic acid)

70

Naming Carboxylic Acids


71/124


Benzoic acid

Propanoic acid

71

O

OH

Naming Esters


72/124


Name begins with alkyl group attached to the OName of parent acid is separate from the alkylgroup name and oic is replaced with ate

Ethyl propanate

72

Learning Check


73/124


What is the name of the following ester?

Alkyl group is propylNumber, starting withthe ester carbonPropyl 4-methylpentanate

73

3

2

1

O

O

4

5

propyl group


74/124

Reactions of Carboxylic Acids


75/124


The COOH is weakly acidic and therefore reactswith base

RCOOH + OH - RCOO- + H 2O

75

Formation of Esters


76/124


Esters give fruits their characteristic odor

ethyl pentanoate76

O

O H + H 3 C C

OH

H

H

O

O

+ H 2O

Saponification


77/124


Strong base reacts with an ester to form alcoholand the esters anion formspentanoate ion

77

Your Turn!


78/124


Name the ester formed when methanol reacts withhexanoic acid.

A. 1-methyl hexanoateB. methylhexanoate

C. methyl hexanoateD. methyl hexan-1-oate

78

Organic Derivatives of Ammonia


79/124


Amines are derived from ammonia with one ormore H atoms replaced with organic groupsLike ammonia, amines are weakly basic

Amines react with acids

79

Acid Property of Protonated Amines


80/124


Ethylmethylammonium ion is the conjugate acidof ethylmethylamine

pK a = 10.76 pK b= 3.24

80

CH 2

N

H

CH 3

H 3 C+ H+CH 2

N

H

CH 3H 3 C

H

ethylmethylamineethylmethylammoniun ion

+H2O

Amides


81/124


General form

Where (H)R indicates either an H atom or an R

group attachedNaming

The name of the parent acid is amended droppingthe oic ending and replacing it with - amide

81

2

Example Names of Amides


82/124


Propanamide

4-ethylhexamide

These are examplesof simple amides

82

Synthesis of Simple Amides


83/124


An organic acid reacts with aqueous NH 3 to forman amide

2-methylpropanoic acid yields 2-methylpropanamide

83


84/124

Amide Reactions


85/124


Urea, an amide, ultimately hydrolyzes to NH 3,CO2 and waterCarbonic acid is formed, which then decomposes

to carbon dioxide and waterThe overall reaction is:

85

Basicity of Amides


86/124


Amides are not basic like aminesThe lone pair on the N atom is delocalized andthus not readily available for donation to a

proton

Amides are neutral in an acid-base sense

86


87/124

Organic PolymersMacromolecule made up of small, repeating units


88/124


Example, polypropylene

Starting material

88

PolymersRepeating unit is called a monomer


89/124


The reaction to create a polymer is known aspolymerization

Chain Growth Polymers

Polymers created by the addition of one monomerto another monomerPolypropylene is an example of a chain growth

polymer

89

Common Polymers


90/124



91/124


92/124

Dacron-A Polyester Another example of a condensation copolymer


93/124



94/124


95/124

Physical PropertiesHDPE is lightweight, water repellent, resists tears


96/124


Common usesStrong mailing envelopes

Tyvek

Ultrahigh molecular weight polyethlene3 to 6 million molar massUHMWPE

Used to make very strong polymersSails, bullet proof vests, bike helmets

96


97/124

Disaccharide

Sucrose


98/124


Sucrose

98

Disaccharide ReactionsDisaccharide molecules split intomonosaccharides


99/124


monosaccharidesGal-O-Glu + H 2O galactose + glucose

Polysaccharides

Starch is a large polymeric sugar moleculeCan be broken down into glucose, which is used forenergy in biochemical reactions

Amylose is the structurally simpler glucose polymerportion of starch

99

Disaccharide Reactions Amylose


100/124


Amylose + n H2O n glucose

100

PolysaccharidesThe majority of starch is made up of a morecomplex polysaccharide known as amylopectin


101/124


complex polysaccharide known as amylopectin

101

Cellulose A polymer of glucose with different oxygenbridge orientations


102/124


bridge orientationsWe lack an enzyme to digest cellulose

102

LipidsWater insoluble natural productsDi l i l l t


103/124


Dissolve in non-polar solventsRelatively non-polar with large segments that are

hydrocarbon-likeCholesterol

103

LipidsFats and oils

Triacylglycerols esters of glycerol and long chain


104/124


Triacylglycerols-esters of glycerol and long chaincarboxylic acids (fatty acids)

104

Fatty Acids


105/124


TriacylglycerolsTriacylglycerol example


106/124


H 2C

HC

C

H 2

O

O

O

C

C

C

O

O

O

CH 2

HC

CH 2

CH 3

CH 2

H 3 C

CH 2

CH 2

CH 3

Reactions of TriacylclycerolsDigestion

Breaks down the triacylclycerol into its three


107/124


Breaks down the triacylclycerol into its threecomponent fatty acids and glycerol. Takes place inbase so in fact the fatty acids are in their anion form

Hydrogenation

The addition of hydrogen to the double bondsTurns oils into solids

107

SoapCastile soap is made from olive oilOlive oil has many different fatty acids


108/124


Olive oil has many different fatty acidsTwo major fatty acid constituents are oleic acid, 50-

85%, and linoleic acid, 4-20%

Saponification of triacylglcerols using NaOH or otherbase, and heat, results in salts of the fatty acidcomponents plus glycerol

Sodium oleate and sodium linoleate, for example

This product mixture, soap, is thus the result ofsaponification of triacylglcerols

108

Cell MembranesGlycerophospholipids

Diacylclcerols with phosphate unit which is attached


109/124


Diacylclcerols with phosphate unit which is attachedto a amino alcohol unit

Contain a hydrophobic, water avoiding, unit and ahydrophilic, water loving, unit

Aggregate together to form lipid bilayers withhydrophilic layers oriented to the outside and insidelayers of the membrane

109

Cell Membranes


110/124


Cell MembranesMembrane also contains protein units, somewhich act as ion channels to move select ions in


111/124


and out of cells

Other proteins act as molecular recognition sitesfor hormones and neurotransmitters

111

ProteinsPolypeptides made up of -amino acidsServe as hormones, neurotransmitters, and


112/124


Serve as hormones, neurotransmitters, andenzymes

Essential amino acids are those the body doesnot synthesizeBasic amino acidstructure:

112

Amino AcidsLysine


113/124


Cysteine

Amino AcidsIsoleucine


114/124


Alanine

114

PolypeptidesFormation of peptide bond

OOH


115/124


H 3 N

O

R

N

O

R'

H

H

H 3 N

O

R

N

O

O

R'

H

2

PolypeptidesCombining two amino acids forms a dipeptideOften the amino acids are abbreviated


116/124


Glycine - Gly

Alanine Ala A dipeptide of these would then be shown as:

Gly- Ala

A few amino acids can be arranged in a verylarge number of orders leading to many different

proteinsGly-Ala-Arg Gly-Arg-Ala Ala-Gly-ArgPlus three more

116

Polypeptides and ProteinsHow many ways can you arrange n differentobjects?


117/124


n ! Therefore 3 amino acids have 6 arrangements

You can also use the same amino acid more thanonce in a polypeptideProteins

Consist of polypeptides and usually small organicmoleculesThey may also incorporate metal ions into theirstructure

117

Structure of Hemoglobin


118/124


Nucleic AcidsRNA ribonucleic acidDNA deoxyribonucleic acid


119/124


The chemical of a gene

Chemical basis of inherited characteristics

119

Nucleic Acid Sugars


120/124


Basic Nucleic Acid Structure

phosphate Sugar phosphate sugar phosphate Sugar phosphate

G G' G"


121/124


Where G is a placeholder for a unique nucleicacid side chainThe sugars are ribose for RNA and deoxyribosefor DNA The groups, G, are:

adenine (A), thymine(T), uracil(U), guanine(G), andcytosine(C)

121

phosphate g p p g phosphate Sugar phosphate

DNA - Double Helix Structure A unique arrangement of amino acids maximizedhydrogen bonding resulting in a pairing ofstrands to form a do ble heli


122/124


strands to form a double helixBase Pairing A only with T

C only with G

122

DNA ReplicationEnzyme catalyzed process unzips the two strands

Arrangement of base pairs dictates replication


123/124


pattern

123

Polypetide SynthesisControlled formation of peptide bonds to make apolypeptideRepeated man times to form pol peptides and


124/124


Repeated many times to form polypeptides andproteinsGenetic information is transcribed from DNA in thenucleus onto RNA ( m RNA)

This messenger RNA moves outside the nucleus andthrough a complex process, using other RNA types,synthesizes a specific protein

The order of amino acid synthesis is coded so thatthe correct amino acids are made available in theproper sequence

124

Date post:	01-Jun-2018
Category:	Documents
Upload:	achmad-rochliadi
View:	234 times
Download:	0 times

Brdy 6Ed Ch23 OrganicPolymersAndBiochemicals

Documents