Chemistry of organic compounds

Bridge course

Organic chemistry is the study of carbong y y

compounds , excluding oxides, carbonates

&bicarbonates. Organic chemistry deals

with hydrocarbons and their derivatives.

O i d i i lOrganic compounds contains mainly

carbon hydrogen & oxygencarbon, hydrogen & oxygen.Vikasana Bridge Course  2012

The total number of organicThe total number of organiccompounds far exceed the totalnumber of inorganic compoundsnumber of inorganic compoundsformed by all the remainingl Th i h d felements. That is the wonder oforganic chemistry.!!

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FriederichWohler(31.7.1800-23.9.1882)

Classification of organic compoundsg pAliphatic compoundsAromatic compoundsAromatic compoundsAlicyclic compoundsHeteroc clic compoundsHeterocyclic compounds

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Aliphatic compounds: these compounds  are 

Called open chain compounds and consists of Straight or branched chain.

Ex; CH3‐CH3  ,                     ,   CH3‐CHCH3

CH3Eth                           I b tEthane            propane             Isobutane

Aromatic compounds : these are cyclic d d Th iunsaturated compounds . The name aromatic

has been derived from the Greek word aromameans smell.(odour).

CH3                 OH3e.g.

Benzene      Toluene           Phenol

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Alicyclic compounds: These are compoundsAlicyclic compounds: These are compoundscontaining rings or closed chains.

       CH  e.g.       CH2 

H2C          CH2                              Cyclopropane cyclobutaneCyc op opa e cyc obuta e

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Heterocyclic compounds: These are cycliccompounds containing hetero atoms like oxygen , nitrogen, sulphur etc.oxygen , nitrogen, sulphur etc.e.g.

N                  SN                  Spyridine         Thiophene

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Functional groups An atom or a group of atoms present in aAn atom or a group of atoms present in amolecule of an organic compoundhi h d t i th ti i ll dwhich determines the properties is called

a functional group.

e.g. C‐C,      ‐C=C‐ ,   C=Og , ,Alkane, alkyne, ketone

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O i   d   t i i   b   d  H dOrganic compounds containing carbon and  Hydrogenonly are called HYDROCARBON

e.g. CH4,    C2H6,     C6H6,      C6H5CH3.

Methane   Ethane   benzene      toluene

hydrocarbonsy

li h i ialiphatic aromatic

saturated unsaturated

alkynesalkenes

Saturated hydrocarbons: these compoundsi b b i l b d h bcontains carbon‐carbon single bond they obey

the general formula CnH2n+2e.g.CH4,C2H6,C3H8 etc.

H

C H H3C‐CH3C H H3C CH3H

HHMethane Ethane

S d h d b   ll   dSaturated hydrocarbons usually undergoSubstitution reactions rather thanaddition reactions. They are also calledAlkanes. These compounds comes underphomologous series.

CH4      C2H6       C3H8     C4H10…

Unsaturated hydrocarbons: These compoundspcontains carbon‐carbon double bond or triplebondtriplebond.

e.g.

H C CH                   HC CHH2C=CH2                  HC=CH

Ethene                       EthyneEthene                       EthyneVikasana Bridge Couse 2012

Unsaturated hydrocarbons with doubleybond are called alkenes.They obey thegeneral formula CnH2ngeneral formula CnH2n

C2H4 C3H6 C4H8C2H4, C3H6, C4H8

Unsaturated hydrocarbons with carbon‐y

carbon triple bond are called alkynes. Their

general formula is CnH2n‐2.

C H C H C H6C2H2, C3H4, C4H6.

A i  h d b    A i  Aromatic hydrocarbons : Aromatic hydrocarbons contains a ring structure with double bonds.e.g.                            CH3g 3

Benzene          Toluene      NaphthaleneBenzene          Toluene      NaphthaleneVikasana Bridge Couse 2012

A t k k lAugust kekule(1829‐1896)

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Uses of hydrocarbonsyLPGCNGCNGGasolineArtificial ripening of fruitsArtificial ripening of fruitsParaffin wax

f f l d lManufacture of plastics and polymersInk, carbon black

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The structure of organic compounds canb   d bbe represented by:Electron dot structureDash line structureCondensed structureBond line structure

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Electron dot structure:

H

H    C    H H    O     H

H

Dash line structure

H

C      H                    H‐O‐HC      H                    H‐O‐HH                     

H                           H                           Methane                      Water

Condensed structureCondensed structure

CH3CH2CH2CH3            CH3(CH2)3CH3

Butane                                 Pentane

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Bond line structure

OHOH

Butane                 propanol

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Substitutions and addition reactions

In substitution reaction  one groupIn substitution reaction, one groupreplaces another. 

CH4+Cl2              CH3Cl +HCl

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chlorination of methane

CH4+Cl2                CH3Cl +HClCH4+Cl2                CH3Cl +HCl

CH3Cl+Cl2    CH2Cl2+HClCH3Cl+Cl2    CH2Cl2+HCl

CH3Cl2+Cl2 CHCl3+HCl

CHCl3+Cl2 CCl4+HCl

Addition reactionsUnsaturated hydrocarbons undergo addition y greactions and move towards saturation.

CH2=CH2+H2            CH3‐CH3

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Addition reaction

HC=CH+Cl2            CH=CH

Cl Cl

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h k Thank You

P k h ilPrakash navilurG.P.U CollegeBidkalkatte.

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