Organic Chemistry

The study of carbon, hydrogen, oxygen and nitrogen containing

compounds

THE HYDROCARBONS

Characteristics contain only carbon and hydrogen non-polar molecules low boiling point - decompose easily sp3 hybridization insoluble in water (most) slow reactivity non-electrolytes (poor ionization)

NOMENCLATURE

The number of carbon atoms is determined by the root part of the name

• meth 1 carbon• eth 2 carbon• prop 3 carbon• but 4 carbon• pent 5 carbon• hex 6 carbon• hept 7 carbon• oct 8 carbon

The Alkanes

Characteristics saturated hydrocarbons (single bonds only) homologous series (follow same pattern) fewer # of carbons - lower boiling points follow same general formula - CnH2n+2

end in -ane

The Alkanes - Saturated hydrocarbonsMethane H

H C H CH4

H

Propane H H HH C C C H C3H8

H H H

Ethane H H H C C H C2H6

H H

Isomers - molecule has the SAME chemical formula, but DIFFERENTstructural formulaButane is the first hydrocarbon to exhibit isomerism.

n- Butane H H H H H C C C C H C4H10

H H H H

2-methyl propane (isobutane) H

H C H H HH C C C H C4H10 H H H

Naming : 1- find longest chain of C atoms and name it 2- name attached group 3- indicate the address of the attached group with number

n-pentane H H H H H H C C C C C H C5H12

H H H H H

2,2-dimethylpropane H(neopentane) H C H

H H H C C C H C5H12

H H H C H

H

2-methylbutane H(isopentane) H C H

H H H H C C C C H C5H12

H H H H

n-hexane H H H H H H H C C C C C C H C6H14

H H H H H H

n-heptane H H H H H H H H C C C C C C C H C7H16

H H H H H H H

n-octane H H H H H H H H H C C C C C C C C H C8H18

H H H H H H H H

Reactions of the Alkanes1. Combustion

Alkane + Oxygen Carbon dioxide + Water Ex.

CH4(g) + 2 O2(g) CO2 (g) + 2 H2O (g)

2. Halogen SubstitutionOne hydrogen from a saturated hydrocarbon is replaced by

a halogen atom forming a halogen substituted hydrocarbon.Ex.

C2H6 + Cl2 C2H5Cl + HCl Two products are always produced.

The Alkenes - Unsaturated hydrocarbons

Characteristics unsaturated hydrocarbons (1 double bond) homologous series (follow same pattern) fewer # of carbons - lower boiling points follow same general formula - CnH2n

end in -ene

The AlkenesEthene H H

C C C2H4

H H

Propene H H H H C C C C3H6

H H

Isomers - The isomers of the alkene series are identified by the placement of the double bond. The molecule is named by indicating the location (by number) of the double bond.

1-butene H H H H C C C C H C4H8

H H H

2-butene H H H H C C C C H C4H8

H H H

Reactions of the Alkenes1. Combustion

Alkene + Oxygen Carbon dioxide + Water

2. Addition A. Hydrogen (hydrogenation) - breaks double bond, adds two

hydrogen atomsAlkene + Hydrogen Alkane C3H6 + H2 C3H8

B. Halogen (halogenation) - breaks double bond, adds two halogen atoms

Alkene + Halogen Halogen substituted hydrocarbon C3H6 + Cl2 C3H6Cl2

The Alkynes - Unsaturated hydrocarbons

Characteristics unsaturated hydrocarbons (1 triple bond) homologous series (follow same pattern) fewer # of carbons - lower boiling points follow same general formula - CnH2n-2

end in -yne

The Alkynes

Ethyne (acetylene)H C C H C2H2

Propyne HH C C C H C3H4

H

1-Butyne H HH C C C C H C4H6

H H

2-Butyne H H H C C C C H C4H6

H H

Reactions of the Alkynes1. Combustion

Alkyne + Oxygen Carbon dioxide + Water

2. Addition A. Hydrogen (hydrogenation) - breaks triple bond, adds four

hydrogen atomsAlkyne + 2 Hydrogen Alkane C2H2 + 2 H2 C2H6

B. Halogen (halogenation) - breaks triple bond, adds four halogen atoms

Alkene + 2 Halogen Halogen substituted hydrocarbon C2H2 + 2 Cl2 C2H2Cl4

The Benzene Series (Aromatic hydrocarbons)

The benzene series consists of molecules which are cyclic in nature.The general formula is CnH2n-6.

Benzene HC

H C C HC6H6

H C C HCH

Although it appears that the structure has alternating double and single bonds, the bonding involves six identical bonds. A resonance structure is used to show structural formula of benzene.

H HC C

H C C H H C C H

H C C H H C C HC CH H

An abbreviated structural formula can be used in place of the above:

OR

Toluene or Methylbenzene C7H8

HC

H C C CH3

H C C HCH

An abbreviated structural formula can be used in place of the above:

CH3 CH3

The Functional GroupsThe Alcohols - Characteristics

Functional Group : -OH hydroxyl group General Formula : R-OH (R stands for a radical -

methyl, ethyl, propyl, etc.) Soluble in water (less than 5 C atoms) Non-electrolyte: 0% ionization Name ends in - ol

Monohydroxy Alcohols

Methanol H H C O H CH3OH

H

Ethanol H H H C C O H C2H5OH

H HProduced by FermentationGlucose zymase Carbon dioxide +

EthanolC6H12O6 CO2 + C2H5OH

1-propanol H H H H C C C OH C3H7OH

H H HThe above is a primary alcohol

2-propanol (isopropyl alcohol)H H H

H C C C H C3H7OHH OH H

The above is a secondary alcohol.The -OH is attached to a C atom which is attached to two others.

1-butanol H H H H H C C C C OH C4H9OH

H H H H

2-butanol H H H H H C C C C H C4H9OH

H H OH H

2-methyl-2-propanol (tertiary butanol)

H H C H H H H C C C H C4H9OH H OH H

Tertiary alcohol - the -OH is attached to a C atom which is attached to three others.

Di-hydroxy Alcohols - contain two -OH groups

OH OH H C C H C2H4(OH)2

H H

1,2-ethanediol (ethylene glycol)anti-freeze

Tri-hydroxy Alcohols - contain three -OH groupsH H H

H C C C H C3H5(OH)3

OH OH OH

1,2,3-propanetriol (glycerine or glycerol)

Saponification - production of soap from the reaction of fatty acid and a base.

Fatty acid + base soap + glycerine

C3H5(C17H35COO) 3 + 3 NaOH 3 C17H35COONa + C3H5(OH)3

Organic AcidsCharacteristics

contain carboxyl group: -COOH ionize weakly - poor electrolytes strong odor short chain compounds are soluble in water name ends in: -oic acid

Structural formula OC O H

Methanoic Acid O (Formic Acid) H C O H HCOOHEthanoic Acid H O(Acetic Acid) H C C O H CH3COOH

H

Propanoic Acid H H O H C C C O H C2H5COOH

H H

EstersCharacteristics

Functional group: -COO- General formula: R-COO-R’ Artificial odors End in -oate Formed from esterification reaction

Acid + alcohol ester + waterRCOOH + ROH RCOOR’ + H2O

Methanol + Acetic Acid Methyl ethanoate + water

CH3OH + CH3COOH CH3COOCH3 + H2OEthanol + Methanoic Acid Ethyl methanoate + water

C2H5OH + HCOOH HCOOC2H5 + H2ONaming of the esters:

1- Name the second R group2- Count the remaining C atoms - name as an alkane, dropping the e and adding -oate

KetonesCharacteristics

Functional group: -CO- General formula R-CO-R’ End in -one

Propanone (Acetone) H O H H C C C H CH3COCH3

H H

Butanone H H O H H C C C C H C2H5COCH3

H H H

AldehydesCharacteristics

Functional group: -CHO General formula: R-CHO End in: -al

Methanal (formaldehyde) HH C O HCHO

Ethanal H H H C C O CH3CHO

H

Ethers

Characteristics Functional group: -O- General formula: R-O-R’ End in: ether

Dimethyl ether H H H C O C HCH3OCH3

H H

Ethyl methyl ether H H H H C O C C H C2H5OCH3

H H H

Amines

Characteristics Functional group: N General formula: R N R”