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STRUCTURE OF FULLERENCES :

(1) A fascinating discovery was the synthesis of spherical carbon-cage molecules called fullerences. The discovery of fullerene was awarded the noble prize in chemistry (1996). Fullerenes   were first prepared by evaporation of graphite using laser.
(2) Fullerences are sooty material so formed consists of C60 with small amount of C70 and other fullerences containing an even number of carbon up to 350
(3) Fullerences have a smooth structure and unlike diamond and graphite, dissolved in organic solvent like toluene.

(4) C60 is the most stable fullerene. It has the shape of a football and called buckminsterfullerene
(5) C60 consists of fused five and six membered carbon rings
(6) Six membered rings surrounded by alternatively by hexagons and pentagons of carbon.
(7) Five membered rings are surrounded by five hexagons carbon rings.
(8) There are 12 five –membered rings
(9) There are 20 Six –membered rings
(10) In fullerenes all the carbon sp2 hybridised each carbon formed three sigma bond and the fourth electron delocalized to formed pi bond .
(11) All the carbon atoms are equivalent but all C-C bond are not equivalent.
(12)  In the structure C-C bonds of two different bond length occur at the fusion of two six membered rings the bond length is C-C = 135.5 pm and at the fusion of five and six membered rings C-C bond length is 146.7 pm.
(13) There are both single and double bonds
(14) The smallest fullerenes are C20.
(15) Thermodynamically the most stable allotrope of carbon is considered to be graphite. This is due standard enthalpy of formation of graphite is taken zero .while enthalpy of formation of diamond and fullerenes are 1.90 KJ/Mole and 38.1 KJ/Mole respectively.      

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