CHAPTER 8 INTRODUCTION TO ORGANIC CHEMISTRY BASIC CHEMISTRY CHM 138.

CHAPTER 8INTRODUCTION TO

ORGANIC CHEMISTRY

BASIC CHEMISTRY

CHM 138

• Organic chemistry: -The branch of chemistry that deals with carbons compounds.

• ‘Organic’ – derived from living organisms

• Study of compounds extracted from living organisms and their natural products.

• Examples: sugar, starch, urea, waxes, carbohydrates, fats and etc

• Human are composed of organic molecules – proteins in skin, lipid in cell membranes, glycogen in livers and the DNA in the nuclei of cells.

ORGANIC CHEMISTRY

Chemistry of carbon:

- Two stable isotops (13C and 12C)

- electron configuration: 1s2 2s2 2p2

- four valence electrons

- can form more compounds than any other element

- able to form single, double and triple carbon-carbon bonds, and to link up with each other in chains and ring structures

HOMOLOGUE SERIES AND FUNCTIONAL GROUPS

Functional group: A group of atoms that is largely responsible for the chemical behavior of the parent molecule.

Functional groups: - hydrocarbons - alcohols - aldehydes - ketones - carboxylic acids - alkyl halides

HYDROCARBONS

• Made up of only hydrogen and carbon

ALKANES

General formula:

CnH2n+2, where n = 1, 2, ….

Only single covalent bonds are present

Known as saturated hydrocarbons because contain the maximum number of hydrogen atoms that can bond with the number of carbon atoms present.

Can be assumed to be sp3-hydridized

Structures of the first four alkanes

The melting and boiling points of the straight-chain isomers of the first 10 alkanes

Homologous Series 

1. Definition: A series of compounds in which each member differs from the next by a specific number and kind of atoms.

2. Alkanes: Differ only at number of (CH2)

3. Series of compounds that has the same functional group.

INITIAL NAMES OF THE HOMOLOGOUS SERIES

Number of carbon atoms, n Name

1 Meth

2 Eth

3 Prop

4 But

5 Pent

6 Hex

7 Hept

8 Oct

9 Non

10 Dec

• The general formula of an alkyl group is CnH2n+1.

• Alkyl groups are used to name organic compounds.

NAMING ALKANES

R= CnH2n+1 (any alkyl group)

R = CH3 — methyl group

R = CH3CH2 — ethyl group

• The letter “R” is often used in formulas to represent any of the possible alkyl groups.

IUPAC RULES International Union of Pure and Applied Chemistry

Consider all alkyl groups attached to it as branch chains or substituents that have replaced hydrogen atoms of the parent hydrocarbon. If two chains of equal length are found, use the chain that has the larger number of substituents attached to it.

The alkane’s name consists of the parent compound’s name prefixed by the names of the alkyl groups attached to it.

RULE 1. Select the longest continuous chain of carbon atoms as the parent compound.

This structure has 2 chains.

CH3 CH2 CH CH2 CH2 CH3

CH3

This chain has 6 carbon atoms.

1 2 3 4 5 6

CH3 CH2 CH CH2 CH2 CH3

CH3

This chain has 4 carbon atoms.

1 2 3

4

This is the longest continuous chain.

CH3 CH2 CH CH2 CH2 CH3

CH3

Select this chain as the parent compound.

1 2 3 4 5 6

CH3 CH2 CH CH2 CH2 CH3

CH3

It is a branch chain and can be considered to have replaced a hydrogen on the parent compound.

1 2 3 4 5 6

This is a methyl group.

CH3 CH2 CH CH2 CH2 CH3

CH3

1 2 4 5 63

The name of the compound is 3-methylhexane.3

3

IUPAC RULES

If the first subsitutent from each end is on the same-numbered carbon, go to the next substituent to determine which end of the the chain to start numbering.

RULE 2. Number the carbon atoms in the parent carbon chain starting from the end closest to the first carbon atom that has an alkyl group substituted for a hydrogen atom.

If the chain is numbered left to right, the isopropyl group is on carbon 5.

isopropyl group

1 2 53 7 864

If the chain is numbered right to left, the isopropyl group is on carbon 4.

isopropyl group

8 7 46 2 135

Use right to left numbering so that the isopropyl group is on the lowest numbered carbon.

4-isopropyloctane

IUPAC RULES

RULE 3. Name each alkyl group and designate its position on the parent carbon chain by a number (e.g., 2-methyl means group attached to C-2).

5 4 2 13

2-isopropyl pentane

2,3-dimethylpentane

5 4 2 13

The methyl group appears twice

RULE 4. When the same alkyl-group branch chain appears more than once, indicate this repetition by a prefix (di-, tri-, tetra- and so forth) written in front of the alkyl group name (e.g. dimethyl indicates two methyl groups).

–The numbers indicating the alkyl-group positions are separated by a command and followed by a hyphen and are placed in front of thename (e.g., 2,3-dimethyl).

RULE 5. When several different alkyl groups are attached to the parent compound, list them in alphabetical order (e.g. ethyl before methyl in 3-ethyl-4-methyloctane). Prefixes are not included in alphabetical ordering (ethyl comes before dimethyl).

methyl

ethyl

1 2 4 53 6 7 83 4

3-ethyl-4-methyloctane

Alkanes can have many different types of substituents.

For example:

CHCH3

NO2

CH

Br

CH3 CH3

1 2 3 4 5

3-bromo-2-nitropentane

CYCLIC HYDROCARBONS

A hydrocarbon that contains carbon atoms joined to form a ring.

Cycloalkanes – all carbons of the ring are saturated

NOMENCLATURE OF CYCLOALKANES

Similar to that alkanes. For examples:

CH3

CH3

CH2CH3methylcyclopentane

=1234

5 6

1-ethyl-3-methylcyclohexane

ISOMERISATION Structural isomers: - Molecules that have the same molecular

formula, but different structure

Three isomers of pentane (C5H12)

STRUCTURE ISOMERS FOR ALKANES

NAME MOLECULAR FORMULA

TOTAL OF ISOMERS

Methane CH4 1

Ethane C2H6 1

Propane C3H8 1

Butane C4H10 2

Pentane C5H12 3

Hexane C6H14 5

Heptane C7H16 9

Octane C8H18 18

Nonane C9H20 35

Decane C10H22 75

ALKENES

Also called olefins Contain at least one carbon-carbon double bond

(C=C) General formula, CnH2n (n=2,3,…) Classified as unsaturated hydrocarbons

(compound with double or triple carbon-carbon bonds that enable them to add hydrogen atoms.

sp2-hybridized For example:

C2H4 - ethylene

CH2 CH2

ALKYNES

Alkynes contain at least carbon-carbon triple bond.

General formula: CnH2n-2, where n = 2, 3,…. Alkyne nomenclature:- Used suffix –yne- Same as alkene nomenclature

HC C CH2CH3 H3C C C CH3

1-butyne 2-butyne

1 2 3 4 1 2 3 4

NamingAlkenes and

Alkynes

NamingAlkenes and

Alkynes

IUPAC RULES

RULE 1. Select the longest continuous carbon chain that contains a double or triple bond.

This chain contains 6

carbon atoms

RULE 2. Name this compound as you would an alkane, but change –ane to –ene for an alkene and to –yne for an alkyne.

This chain contains 8

carbon atoms

This is the longest continuous chain. Select it as the parent compound.

Name the parent compound octene.

This chain contains a triple bond. Name the parent compound octyne.

RULE 2. Name this compound as you would an alkane, but change –ane to –ene for an alkene and to –yne for an alkyne.

RULE 3. Number the carbon chain of the parent compound starting with the end nearer to the double or triple bond. Use the smaller of the two numbers on the double- or triple-bonded carbon to indicate the position of the double or triple bond. Place this number in front of the alkene or alkyne name.

IUPAC RULES

This end of the chain is closest to the double bond. Begin numbering here.

The name of the parent compound is 1-octene.

IUPAC RULES

8

7

4 3 2 1

6

5

The name of the parent compound is 1-octyne.

IUPAC RULES

8

7

4 3 2 1

6

5

RULE 4. Branched chains and other groups are treated as in naming alkanes. Name the substituent group, and designate its position on the parent chain with a number.

IUPAC RULES

This is an ethyl group.

8

7

4 3 2 1

6

5

The ethyl group is attached to carbon 4.

4

4-ethyl-1-octene

IUPAC RULES

7

4 3 2 1

6

5

8

The ethyl group is attached to carbon 4.

4

4-ethyl-1-octyne

• must specify whether the molecule is cis or trans (geometric isomer)

• cis – two particular atoms (or groups of atoms) are adjacent to each other

• trans – the two atoms (or groups of atoms) are across from each other

C CH3C

H

CHCH3

H

CH3C C

H3C

H

H

CHCH3

CH3

4-methyl-cis-2-pentene 4-methyl-trans-2-pentene

CYCLOALKENES Contains C=C in the ring

cyclopropene cyclobutene cyclohexenecyclopentene

Nomenclature of cycloalkenes:- Similar to that alkenes- Carbons atoms in the double bond are designated C1 and C2

CH31

23

4

5

6

1

23

4

5

1-methylcyclohexene 1,5-dimethylcyclopentene

AROMATIC HYDROCARBONS

Contain one or more benzene rings

benzene ring

Benzene Kekulé Structure

3 double bonds

6 carbons in a ring

The corner of each hexagon represents a carbon and a hydrogen atom.

The structure of benzene can be represented in two abbreviated ways.

Naming Aromatic Compounds

Naming Aromatic Compounds

• A substituted benzene is derived by replacing one or more of benzene’s hydrogen atoms with an atom or group of atoms.

A monosubstituted benzene has the formula C6H5G where G is the group that replaces a hydrogen atom.

All hydrogens in benzene are equivalent.

It does not matter which hydrogen is replaced by G.

Monosubstituted Benzenes

Monosubstituted Benzenes

• Some monosubstituted benzenes are named by adding the name of the substituent group as a prefix to the word benzene.

• The name is written as one word.

nitrobenzene

nitro group

ethylbenzene

ethyl group

Certain monosubstituted benzenes have special names.

These are parent names for further substituted compounds.

methyl group

toluene

hydroxy group

phenol

carboxyl group

benzoic acid

aniline

amino group

C6H5— is the phenyl group.• It is used to name compounds that cannot be easily named as

benzene derivatives.

diphenylmethane 4-phenyl-2-pentene

CH3CH=CHCHCH3

Disubstituted BenzenesDisubstituted Benzenes

Three isomers are possible when two substituents replace hydrogen in a benzene molecule.

• The prefixes ortho-, meta- and para- (o-, m- and p-) are used to name these disubstituted benzenes.

ortho-dichlorobenzene(1,2-dichlorobenzene)mp –17.2oC, bp 180.4oC

ortho disubstituted benzene

substituents on adjacent carbons

meta-dichlorobenzene(1,3-dichlorobenzene)mp –24.82oC, bp 172oC

meta disubstituted benzene

substituents on adjacent carbons

para-dichlorobenzene(1,4-dichlorobenzene)mp 53.1, bp 174.4oC

para disubstituted benzene

substituents are on opposite sides of the benzene ring

phenol m-nitrophenol

When one substituent corresponds to a monosubstituted benzene with a special name, the monosubstituted compound becomes the parent name for the disubstituted compound.

When one substituent corresponds to a monosubstituted benzene with a special name, the monosubstituted compound becomes the parent name for the disubstituted compound.

toluene m-nitrotoluene

Tri- and Polysubstituted Benzenes

Tri- and Polysubstituted Benzenes

Numbering starts at one of the substituent groups.

The numbering direction can be clockwise or counterclockwise.

Numbering must be in the direction that gives the substituent groups the lowest numbers.

• When a benzene ring has three or more substituents, the carbon atoms in the ring are numbered.

4

6

5

2

3

1

clockwise numbering

1,4,6-trichlorobenzene

4-chloro

1-chloro

6-chloro

4

2

3

6

5

1

counterclockwise numbering

1,2,4-trichlorobenzene

4-chloro

1-chloro

2-chloro

chlorine substituents have lower numbers

• When a compound is named as a derivative of the special parent compound, the substituent of the parent compound is considered to be C-1 of the ring.

toluene

5

16

34

2 5

16

34

2

2,4,6-trinitrotoluene

(TNT)

ALCOHOLS

Alcohols: Organic compounds containing hydroxyl (-OH) functional groups.

R OH

Phenols: Compounds with hydroxyl group bonded directly to an aromatic (benzene) ring.

OH

According to the type of carbinol carbon atom (C bonded to the –OH group).

CLASSIFICATION

C OH

Classes:

i) Primary alcohol

- -OH group attached to a primary carbon atom

ii) Secondary alcohol

- -OH group attached to a secondary carbon atom

iii) Tertiary alcohol

- -OH group attached to a tertiary carbon atom

TYPE STRUCTURE EXAMPLESTYPE STRUCTURE EXAMPLES

i) Primary (1°)

ii) Secondary (2°)

iii) Tertiary (3°)

CRH

OHH

CRH

OHR'

CRR''

OHR'

CH3CH2-OH CH3CHCH2

CH3

OH

ethanol 2-methyl-1-propanol

H3C CH

OH

CH2CH3OH

2-butanol cyclohexanol

2-methyl-2-propanol

C

CH3

OH

CH3

H3C

• Alcohols that contain more than one OH group attached to different carbons are called polyhydroxy alcohols.

• Monohydroxy: one OH group per molecule.

• Dihydroxy: two OH groups per molecule.

• Trihydroxy: three OH groups per molecule.

Polyhydroxy Alcohols

Naming AlcoholsNaming Alcohols

IUPAC RULES

1. Select the longest continuous chain of carbon atoms containing the hydroxyl group.

2. Number the carbon atoms in this chain so that the one bonded to the –OH group has the lowest possible number.

3. Form the parent alcohol name by replacing the final –e of the corresponding alkane name by –ol. When isomers are possible, locate the position of the –OH by placing the number (hyphenated) of the carbon atom to which the –OH is bonded immediately before the parent alcohol name.

4. Name each alkyl branch chain (or other group) and designate its position by number.

Select this chain as the parent compound.

This is the longest continuous chain that contains an hydroxy group.

43

2 1

This end of the chain is closest to the OH. Begin numbering here.

43

2 1

3-methyl-2-butanol

Select this chain as the parent compound.

This is the longest continuous chain that contains an hydroxy group.

4 3

2 1

5

This end of the chain is closest to the OH. Begin numbering here.

3-methyl-2-pentanol

4 3

2 1

5 3

2

EXAMPLE

1) Longest carbon chain = 4 carbons = root name: butanol2) Position of –OH group = second carbon atom = 2-butanol3) Name of substituents = 1-bromo = 3-methyl = 3-methyl

COMPLETE IUPAC NAME = 1-bromo-3,3-dimethyl-2-butanol

CCH3

CH3

CH3

CH CH2 Br

OH

1234

EXAMPLES OF POLYHYDROXY ALCOHOL

CH2 CH2

OH OH

1,2-ethanediol

CH2 CH

OH OH

CH2

OH

1,2,3-propanetriol

• An ether has the formula ROR´. • R and R´ can be the same or different

groups.

• R and R´ can be saturated, unsaturated or aromatic.

• Saturated ethers have little chemical reactivity but are often used as solvents.

EthersEthers

• Alcohols and ethers are isomeric.

• They have the same molecular formula but different structural formulas.

• An alcohol and its isomeric ether have different chemical and physical properties.

CH3CH2OH

ethanolB.P. 78.3oC

hydrogen bondssoluble in water

C2H6O

CH3–O–CH3

dimethyl etherB.P. –27.3oC

does not hydrogen bondinsoluble in water

C2H6O

Naming EthersNaming Ethers

Common Names

Common names of ethers are formed from the names of the groups attached to the carbon atom in alphabetical order followed by the word ether.

CH3CH2CH2 — O — CH2CH3

propyl ethyl

ethyl propyl ether

ether

IUPAC RULES

RO– is an alkoxy group. Ethers are named as alkoxy derivatives of the

longest carbon-carbon chain in the molecule

IUPAC RULES

1. Select the longest carbon-carbon chain and label it with the name of the corresponding alkane.

2. Change the –yl ending of the other hydrocarbon group to –oxy to obtain the alkoxy group name.

3. Combine the names from steps 1 and 2, giving the alkoxy name first, to form the ether name.

ethyl

Label it with the name of the corresponding alkane.Change the name of the other hydrocarbon group to –oxy.

CH3CH2CH2 — O — CH2CH3

This is the longest carbon-carbon chain.

propane ethoxy

IUPAC name: ethoxypropane

Trivial name: ethyl propyl ether

ALDEHYDES AND KETONES

Functional group: carbonyl group

C O

Aldehyde: one hydrogen atom is bonded to the carbon in the carbonyl group.

Ketone: the carbon atom in the carbonyl group is bonded to two hydrocarbon groups.

C

O

R'RC

O

HR

ketone aldehyde

R, R' = substituents

Naming AldehydesNaming Aldehydes

The IUPAC names of aldehydes are obtained by dropping the –e and adding -al to the name of the parent hydrocarbon.

butane butanal al

• The parent hydrocarbon is the longest chain that carries the –CHO group.

4

3 2

1

• This chain has 4 carbon atoms.

• The parent hydrocarbon is the longest chain that carries the –CHO group.

4 3 2

1

• This chain has 5 carbon atoms.

5

4 3 25

3-methylpentanal

1

• The –CHO group is always at the beginning of the carbon chain. The carbonyl carbon is numbered as carbon 1.

1

• The common names of aldehydes are derived from the common names of the carboxylic acids.

butyric acid butyraldehyde

• The –ic acid or –oic acid ending of the acid name is dropped and is replaced with the suffix –aldehyde.

Naming KetonesNaming Ketones

The IUPAC name of a ketone is derived from the name of the alkane corresponding to the longest carbon chain that contains the ketone-carbonyl group.

• The parent name is formed by changing the –e ending of the alkane to -one.

propane propanone one

If the carbon chain is longer than 4 carbons, it’s numbered so that the carbonyl carbon has the smallest number possible, and this number is prefixed to the name of the ketone.

This end of the chain is closest to the C=O. Begin numbering here.

3-hexanone

4321 5 6

• The common names of ketones are derived by naming the alkyl or aryl groups attached to the carbonyl carbon followed by the word ketone.

ethyl propyl ketone

ethyl propyl

ALKYL HALIDES

General formula: CnH2n+1X where n = 1,2,… and X (halogen)

Functional group: halogen, -X (X = F, Cl, Br, I)

Naming alkyl halides: - same as nomenclature of alkanes

CH3 ICH3 CH2 CH

CI

CH

CH3

CH3C CH2 CH CH3

CH3

Br

CH3

CH2CH3

iodomethane 3-chloro-2-methylpentana

12345 12345

4-bromo-2,4-dimethylhexane

6

AMINES

• Functional group:

• Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair

Primary amine Secondary amine Tertiary amine

• Classification of amines:

Primary (1o) amine: one hydrogen of ammonia is replaced by an alkyl or aryl group

Secondary (2o) amine: two hydrogens of ammonia is replaced by an alkyl or aryl group

Tertiary (3o) amine: three hydrogens of ammonia is replaced by an alkyl or aryl group

Quaternary (4o) amine: an ion in which nitrogen is bonded to four alkyl or aryl groups and bears a positive charge

NH3C CH3

CH3

CH3

NAMING AMINES

Common names:

- formed from the names of the alkyl groups bonded to nitrogen, followed by the suffix –amine.

- the prefixes di-, tri-, and tetra- are used to decribe two, three or four identical substituents.

CH3 CH2 NH2

ethylamine

CH3 CH2 NCH3

CH3

ethyldimethylamine

(CH3CH2CH2CH2)4N+ -CI

tetrabutylammonium chloride

NCH3

CH3

cyclohexyldimethylamine

NAMING AMINES IUPAC names:

- similar to that alcohols.- the longest continuous chain of carbon atoms determine the root name.- the –e in alkane name is changed to –amine, and a number shows the position of the amino group along the chain.- other substituents on the carbon chain are given numbers, and the prefix N- is used for each substituent on nitrogen.

CH3 CH2 CH CH3

NH2CH3 CH

CH3

CH2 CH2

NH2

CH3 CH2 CH CH3

NHCH3 CH2CH3 CH CHCH3

NCHCH3

CH3CH3

CH3

2-butanamine

1234 1234

3-methyl-1-butanamine

1234

N-methyl-2-butanamine 2,4, N, N-tetramethyl-3-hexanamine

CARBOXYLIC ACIDS

Functional group: carboxyl group, -COOH

C

O

OH

• The carboxyl group can also be written as

or

• Open-chain carboxylic acids form a homologous series.

• The carbonyl group ( ) is always at the beginning of a carbon chain.

• The carbonyl carbon atom is always designated as C-1.

3 2 1

The IUPAC name of a carboxylic acid is derived from the name of the alkane corresponding to the longest carbon chain that contains the carboxyl group.

• The parent name is formed by changing the –e ending of the alkane to –oic acid.

methanone oic acid methane

C

O

OHCHCH3

2-bromopropanoic acid

123C

O

OHCHCHCH3

CH3CH3Br

1234

2,3-dimethylbutanoic acid

Examples of carboxylic acid

Organic acids are usually known by common names.

These names usually refer to a natural source of the acid.

ethanoic acid

IUPAC name

acetic acid

common name

methanoic acid

IUPAC name

formic acid

common name

CARBOXYLIC ACID DERIVATIVES

Group replacing the –OH group of

RCOOH

Class of compound

General formula

Example

-X (halogen) Acyl halide

-OR’ Ester

-NH2 Amide

Acid anhydrideO C

O

R'

R C

O

X

R C

O

OR'

R C

O

NH2

R C

O

O C R'

O

H3C C

O

NH2

ethanamide

H3C C

O

OC2H5

ethyl ethanoate

H3C C

O

CIethanoyl chloride

H3C C

O

O C CH3

O

ethanoic anhydride

EstersEsters

carbonyl group

OR´ bonded to a carbonyl

carbon.

An ester is an organic compound derived from a carboxylic acid and an alcohol.

The ester functional group is –COOR.

Esterification is the reaction of an acid and an alcohol to form an ester.

acetic acid(ethanoic acid)

ethyl alcohol(ethanol)

ethyl acetate(ethyl ethanoate)

According to the IUPAC system the alcohol part of the ester (R΄) is named first.

ethyl

IUPAC NAME

• This is followed by the name of the acid where the –ic ending of the acid has been changed to –ate.

ethanoate

IUPAC NAME

According to the IUPAC system the alcohol part of the ester (R΄) is named first.

This is followed by the name of the acid where the –ic ending of the acid has been changed to –ate.

ethyl ethanoate

IUPAC NAME

COMMON NAME

• The alcohol part is named first (derived from the common names of alcohol).

• The common names of esters are derived by adding –ate to the name of the acid.

acetate acetic acid → ethyl

ethyl acetate

COMMON NAME

• The alcohol part is named first (derived from the common names of alcohol).

• The common names of esters are derived by adding –ate to the name of the acid.

AmideAmide Amide: a composite of a carboxylic acid and

ammonia or an amine. Classification of amide:

i) primary amide: RCONH2 (two H atoms bonded to N atom)ii) secondary amide: RCONHR’ (one H atoms bonded to N atom)iii) tertiary amide: RCONR’R” (no H atoms bonded to N atom)

NAMING AMIDE

IUPAC name:

i) primary amide

- first name the corresponding acid. Drop the –ic acid or oic acid, and add the suffix –amide.

CCH3 NH2

O

CCH3 OH

O

NH3

ethanoic acid ethanamideammonia

acetic acid acetamide

IUPAC name

Common name

NAMING AMIDE IUPAC name:

i) secondary and tertiary amide

- treat the alkyl groups on nitrogen as substituents, and specify their position by the prefix N-.

CCH3 NH

O

CH2CH3 CCH3 N

O

CH2CH3

CH3

IUPAC Name N-ethylethanamide

Common name N-ethylacetamide

N-ethyl-N-methylethanamide

N-ethyl-N-methylacetamide

Acyl halide / acid halidesAcyl halide / acid halides

Naming acid halides:

- replacing the –ic acid suffix of the acid name with –yl and the halide name.

R C

O

X

CCH3 F

O

CCH3CH2

O

CI

IUPAC Name

Common name

ethanoyl fluoride

acetyl flouride

propanoyl chloride

propionyl chloride

Acid anhydrideAcid anhydride

Naming acid anhydride:

- the word acid is changed to anhydride in both the common and the IUPAC name

CCH3

O

CCH3

O

O

IUPAC Name

Common name

O C CH3

O

C H

O

ethanoic anhydride

acetic anhydride

ethanoic methanoic anhydride

acetic formic anhydride

FUNCTIONAL GROUPS OF

ORGANIC COMPOUNDS

• A polymer is a high molar mass molecular compound made up of many repeating chemical units.

Naturally occurring polymers

•Proteins

•Nucleic acids

•Cellulose

•Rubber

Synthetic polymers

•Nylon

•Dacron

•Lucite

POLYMERS

• The simple repeating unit of a polymer is the monomer.

• Homopolymer is a polymer made up of only one type of monomer

( CF2 CF2 )n

Teflon

( CH2 CH2 )n

Polyethylene

( CH2 CH )n

Cl

PVC

• Copolymer is a polymer made up of two or more monomers

Styrene-butadiene rubber

( CH CH2 CH2 CH CH CH2 )n

Formation of Polyethylene

nCH2=CH2 → CH2 CH2[CH2 CH2]n CH2 CH2 CH2 CH3

ethylene monomerpolyethylene

• n = the number of monomer units.

• n ranges from 2,500 to 25,000

SOME MONOMERS AND THEIR COMMON

SYNTHETIC POLYMERS

USES AND IMPORTANCE OF ORGANIC COMPOUNDS

NYLON

• General reactions:

• Nylons are condensation copolymers formed by reacting equal parts of a diamine and a dicarboxylic acids, so that peptide bonds form at both ends of each monomer in a process analogous to polypeptides biopolymers.

DiaminesDicarboxylic acids Nylon

Basic concepts of nylon production

• The first approach: - combining molecules with an acid (COOH) group on each end are reacted with two chemicals that contain amine (NH2) groups on each end.- Form nylon 6,6, made of hexamethylene diamine with six carbon atoms and acidipic acid, as well as six carbon atoms.

• The second approach: - a compound has an acid at one end and an amine at the other and is polymerized to form a chain with repeating units of (-NH-[CH2]n-CO-)x.- Form nylon 6, made from a single six-carbon substance called caprolactam.

Uses and important of nylon

Apparel: Blouses, dresses, foundation garments, hosiery, lingerie, raincoats, ski apparel, windbreakers, swimwear, and cycle wear

Home Furnishings: Bedspreads, carpets, curtains, upholstery

Industrial and Other Uses: Tire cord, hoses, conveyer and seat belts, parachutes, racket strings, ropes and nets, sleeping bags, tarpaulins, tents, thread, monofilament fishing line, dental floss

AZO-DYES

• Azo compounds: - compounds bearing the functional group R-N=N-R', in which R and R' can be either aryl or alkyl. - N=N group is called an azo group - HNNH is called diimide

• Aryl azo compounds have vivid colors, especially reds, oranges, and yellows

Yellow azo dye

Methyl orange - used as acid-base indicators due to the different colors of their acid and salt forms

Artist’s paints – clays, yellow to red range Dye in food and textiles

Uses and important of azo dye

E102: Tartrazine                                      

E107 : Yellow 2G                                                                

E110 : Sunset Yellow                                        

E122 : Azorubine                                      

EXAMPLES OF AZO DYES USED

IN FOOD

E123 : Amaranth                                       

E124 : Ponceau 4R                                

E129 : Allura Red                             

E151 : Brilliant Black                                                          

FUEL Any material that is burned or altered to obtain energy and

to heat or to move an object Its energy can be stored to be released only when needed,

and that the release is controlled in such a way that the energy can be harnessed to produce work

Examples: Methane, petrol and oil. Application of energy released from fuels:

- cooking

- powering weapons to combustion

- generation of electricity Fuel oil: generate heat or used in an engine for the

generation of power