Which of the following are aromatic

hi

yes

how second follows huckels rule as well as last one?

it is homoaromatic compound. A homoaromatic compound is defined as a compound that contains one or more sp3 hybridised carbon atom in a conjugated cycle . In order for the pi orbitals to overlap more effectively so as to close a loop the sp3 atoms are forced to lie almost vertically above the plane of the aromatic system When cyclooctatetraene is dissolved in acid ( concern.H2SO4) the H+ ion is added to one of the double bonded carbon to form homotropylium ion . In this spices aromatic sextet is spread over seven carbon atom as in tropylium ion . The eight carbon is sp3 carbon atom & it can't take part in aromaticity

according to huckels rula compound must be planar na so last wala aromatic nahi hona chahiye na?

yes, hoga... is case me peripheral resonance possible he. mean peripheral double bonds aromaticity show krege

ye special case he to apko concept alg se dhyan rkhna pdega is compound k liye

ohhkk

Total 3 aromatic molecules

please ask if any doubt in this

hi

sir last compound

according to huckels rule, for aromaticity it must be planar

see the last compound is an example of peripheral aromaticity ...here it is 14 pi electrons so follow huckel rule

and last one (4n+2) π electron rule bhi nahi follow ho raha na?

18 electron hona chahiye na 14 kaise? 4 rings he to

nhi pi bonds count honge...pi electrons count hote hai na

7 pi bonds...peripheral aromaticity

see

(4n+2 ) π electron hone chahiye, isme n matlab no. of rings hi hota he na? and also, aromatic compounds planar hote he na last wala planar bhi nahi he

n is only integer value

ohhk👍🏻

sir E wala aromatic kyu nahi? localised str. kaise usme bhi pi electron he na jo delocalise honge?

kuch compound deviate krte hai aromaticity se..ye dimethyl fulvene me bhi hota hai