Classification of organic compounds

Presentation

1. Classification of Organic
Compounds
By Asaye D.
2019
Classification of Organic
Compounds

2. Introduction
Organic
Molecules
Other classes of
Organic Molecules
Hydrocarbons
[C & H only]

3. Classification of Organic Compounds
Organiccompoundsconstituteabout90%ofallcompounds.
Dependinguponthearrangementofcarbonatomsintheir
structure,organiccompoundsarebroadlycategorizedinto
1.Acyclic or Open Chain compounds
2.Cyclic or Closed Chain compounds

4. Thecarbonatomsarepresentintheformofanopenchain.
Thischainmayeitherbeastraightchainorabranchedchain.
ThesewereinitiallyknownasAliphaticcompoundsbecausethe
compoundsofthisclasswerederivedfromeitheranimalorvegetable
fats
StraightChainCompounds:Thecarbonskeletonisintheformofa
straightchain.
Examples:
n-PropaneCH
3-CH
2-CH
3
PropeneCH
2=CH-CH
3
Branched Chain Compounds:The carbon skeleton is in the form of a
branched chain.
Examples: Isobutylene
Acyclic or Open Chain Compounds
Thecarbonatomsarepresentintheformofanopenchain.
Thischainmayeitherbeastraightchainorabranchedchain.
ThesewereinitiallyknownasAliphaticcompoundsbecausethe
compoundsofthisclasswerederivedfromeitheranimalorvegetable
fats
StraightChainCompounds:Thecarbonskeletonisintheformofa
straightchain.
Examples:
n-PropaneCH
3-CH
2-CH
3
PropeneCH
2=CH-CH
3
Branched Chain Compounds:The carbon skeleton is in the form of a
branched chain.
Examples: Isobutylene

5. Theyare marked by the presence ofone or more closed chainsor
ring of atomsin their structure.
Dependingon whether there is a presence of any other atom apart
from carbon in the constitutionof the ring, they are further
classified as:
Homocyclic or Carbocyclic Compounds
Heterocyclic Compounds
Cyclic or Closed Chain Compounds
Theyare marked by the presence ofone or more closed chainsor
ring of atomsin their structure.
Dependingon whether there is a presence of any other atom apart
from carbon in the constitutionof the ring, they are further
classified as:
Homocyclic or Carbocyclic Compounds
Heterocyclic Compounds
Homocyclicor Carbocyclic Compounds
Theringsinthesecompoundsareentirelymadeupofcarbonatoms.
Nootheratomispresentintheringskeleton.
Thesecanbefurtherdividedintotwosub-classes:
AlicyclicCompounds
AromaticCompounds

6. AlicyclicCompounds
TheirnameisattributedtotheirresemblancetoAliphatic
compoundsintheirproperties.
Compoundthatisbothaliphaticandcyclic
Theexamplesofthiscategoryincludecyclopropane,cyclobutane,
cyclopentane,cyclohexane,etc.
AromaticCompounds
Thesearecyclicunsaturatedcompounds.
TheyderivetheirnamefromtheGreekwordAromawhichmeans
“fragrantsmell”sincemostofthesecompoundsbearapleasant
smell.
Thesearefurtherclassifiedintotwotypes:
BenzenoidAromaticCompounds
Non-BenzenoidaromaticCompounds

7. i).BenzenoidAromaticCompounds:
Theyarecharacterizedbythepresenceofoneormorefusedor
isolatedbenzeneringsaswellastheirderivativesintheir
structure.
Dependinguponthenumberofbenzeneringsthatarefused
togetherintheirstructure,theycanbefurtherclassifiedas
Monocyclic,Bicyclic,Tricyclic.
ii).Non-BenzenoidaromaticCompounds:
Theyarecharacterizedbythepresenceofasinglebenzeneringto
whichothergroupsareattached.
i).BenzenoidAromaticCompounds:
Theyarecharacterizedbythepresenceofoneormorefusedor
isolatedbenzeneringsaswellastheirderivativesintheir
structure.
Dependinguponthenumberofbenzeneringsthatarefused
togetherintheirstructure,theycanbefurtherclassifiedas
Monocyclic,Bicyclic,Tricyclic.
ii).Non-BenzenoidaromaticCompounds:
Theyarecharacterizedbythepresenceofasinglebenzeneringto
whichothergroupsareattached.
Aniline

8. Bicyclicand Tricyclic Compounds
These are characterized by the presence oftwo or more rings in their structure.
Examplesinclude Naphthalene,Phenanthreneas well asAnthracene.
AnthracenePhenanthrene
Naphthalene
Non-BenzenoidAromatic Compounds
Aromaticcompoundsthatcontainotherhighlyunsaturatedringsinplaceofthe
benzeneringarecallednon-benzenoidaromaticcompounds.
Examplesinclude
Non-BenzenoidAromatic Compounds
Aromaticcompoundsthatcontainotherhighlyunsaturatedringsinplaceofthe
benzeneringarecallednon-benzenoidaromaticcompounds.
Examplesinclude
Azulene Tropolone

9. Whenoneormoreheteroatomssuchasoxygen,nitrogen,sulphur,boron,
siliconetc,arepresentintheringsuchcompoundsareknownasheterocyclic
compounds.
Heterocyclic Compounds
Alicyclicheterocycliccompounds:Aliphaticheterocycliccompoundsthat
containoneormoreheteroatomsintheirrings
Aromaticheterocycliccompounds:Aromaticheterocycliccompoundsthat
containoneormoreheteroatomsintheirringskeleton