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* h okicity
Sel => AROMATICITY :-
FE Imthoduction :-
X Ahomaticity b a chemical probaty of Ohgamni't
Comboumdh-
® Ahomatic combourn dd have llowing chonactemsha.
® They have high degnee of siability
@® They hhowh electhobhilic bubkitubon heachows Rather,
tham electhobhilic addition heachows- Tt meanrs
that they does mot decolounse bhomine Wateh
Solution.
® Anomatic compounds follow Huckel Rule. Accohding to
Og plaman , comjugated species
havin (Um 42) R-electhoms (whare “= 014,23)
W ohomatic im nature,
@ There ib a diamagnetic hing current.
Each carbom ~mubt be sp - bridibed on bb-
hybhidized.
© Det Pate high deghee of phability due to filled
ponding MO,
ef
Cpa
Yxaea een eee
(nematic ). (Anownatic )
+ ee degree of eabilltyn wf
* Hig degree of stability ‘uw Socialed with rehonance
} emehay.
% The Comboumd which have mohe tesomamce em ehay ib
; smone btable. oY
x The comboun d which have mone potential energy least stable.
ie.
* Anomaticity x Resomance emergy (Re) * Stability
eo te
Polembial energy (PE)
% Greater the hesomamce em eray » high er willbe We
stabil ity of compound,
x RE of Some ahomatic combounds dhe given
below :-
Oui @ Li
°
4 S$
mol om
ge beat 24 keal/mnal sale Herel
32 Keal/-mol . 19) IO 41 Keal |-mol .
+ Preremce of diamagnetic himg Curent t-
J Hasietding (met) = Ho-Hi
bp? > Ab > Ab Gerreating onder ) due 4o
Aminotnobic effect:
% Molecule im which outa bhotows are deshielded and
inn eh brotoms are bhielded i kia diatrobic molecule.
These tybe of molecules ane always ahomate im
mature.
% Molecule im which outer prot om are bhielded and
imme brotomb che dehielded ih kla paratropic
molecule. Panatrobic molecule aromatic im
~ mature.
X Aromatic comboumd show diana
metho hy current
due to pare electhom, 4g “g
% Am#arom atic comboumds bhow
ohamaamedic hy
Cumemt due 4o umbained e-. ire mq Highly bhielded
. pholowm
Mow § Value).
@. Arnanyge the following comboumds im. ohden of
if cremahicity?
a6 ® OO cea
Sel Resonance emerg of each bhecies wiunuees
below 10 Atnuctuke» Greater the Nehowiaones'
tmogy per benzeme hing high will be cthe:
stability of molecule @©#=3 6 54
4
$4 2246 © B = 23-69
2
*“1[O>@O@>60 Arommaticity. ohd en .
x—*—*+
YIP PIII IAI IIH
=> HUCKEL RULE
ul hule to ident:
% Thib ba vey popula» amd ureft e
Gromaticity im wmomocyclic conju ated combosnd.
x Accor ding to Huckel
nutes a plan ar momo cle
Comjugted syst ewn having (Ym +2) n delocalized P
(wh ere a = 0, 1,2,3...) elechom ane k/a ahomahe
comboumd . Eq: Bemzems, Naphthalene, Furam,,
Pymnole 1 ete. ae 7
* ms0 —» (Yxo+2) Me = 2ne
meh —_— (4x 2+2) Te- = 6Re-
we BP peeies (4x 249) he- = lonme-
MES — > (4x342)Me- = tUuKeH.
n=4 —> (4xu+2) Fe~ = 19 Aen.
x Am aromatic Com umd should has Comb mucous
delocalization of “A- electoms (electhows inn b -onbitaly)
with on without art cibatom of lome bain
-ve change /+ve chan ge (re. having electom © on
Vacant b-ohbitals).
* The p-onbital, im which
e
the elecrom ohe
delocalizing must be ponaltel 4o each othe bo
thal a comfmucur overla of Aecthoms iy powible
Along the hing
¥ So, whenever
a cuclic,
electhoms one
Plamen amd (Umer) x
ComPrnuously
delocalized, it leads 46 the extra stability of the molecule refoned to
A anomaticity. On the other hand, whenev®
qa
Cuclic, plone amd lum) K-e7 ahe comtimuousl
delocalize. 1 it leads to the extra deebility
of the molecule hefernred 4o oh amhohomaticity-
Whem either the molecule & not
i mot blamah oh the comtimuows
OF electhoms in molthere, the mol
cyclic on it
delocalization
ecule
aliphatic Oh mom Gdhomatc.
=> CRAIG'S RULE:-
% This hule us abblicable fon polyey clic ane
benzemnoid Commboumnds.
® If molecule comtain Cr-axik, them coum}
total number of double bomds (N), value
5
N-41 decides ohomaticity im comoumd f
a &9 Azulene :
| Pemtal enn e
NES i
N-1= Ux-bomd i
© veny “” Nzy
Anommatic. Noa = 3n-bomd
vledd)
GO Nom ahem atte
Oye
: N-ae S (oda) _
Nome 7
Heblalene Om- Ahowmadtie. *% The Ohgamic Combound uhich show ahomaticity
Ae Dhomatc im nature oh diathobic .,i9
Matiuhe and’ the protons (outside the. hienghs )
hignal always exist auay Som “the
TS (there protomh ohe deshield ed -protoms).
III It I 9
=> LDENTIFICATION OF ARomATiIc.
NON-AROMATIC AND ANTI-AROMA-
ENT AROMA
TIC COMPOUNDS :—
+ Aromatic =
@ Hackel’s rule:
e Momocy clic bystem,
© Plaman.
° Sp3-
eUn+2) n-elechom.
© Delocalizahom of electhoww.
H Anti- aromatic. .
ee
eo Plaman. : / otPolyeuclic AybLewm,
© (4m) -% ~dectrow,, - bo brosent if).
@ bb on bbe hybnidized. ® NBL!
@ Craig ules
@ Polycyclic tyhtem,
2 fa prerent (if).
1 NE even luna),
Dhomatic,
@ raign hale .~
(un) y.
e- FE Nom - onomatic :— .
2 et,
° Restriction of delocalizaton of he e-.
L2® Not blaman.
S& Nok bb.
Re yy yy
=>. CALCULATION OF - ELECTRONS‘
a
* During ‘K dechon ‘Coumt
Count 20- decthow, °
Coumt 27 electhon,.
% The tome
, double bod
amd tab le bond . abo
ah im
comjugation ty albo :
Counted ab 2 e-
oS meee
° = Uh en. Ws uoceoM =
. ; tan ply ®
° Tt): one + a4dp. = nen, io ¢
° DD une ttl. = 6 Hex,
v SP ean 67 e.
x Spies im uohich dome ban th met im
commjug ati om with double J Jib le’ bond,
Ww mot coumled ive: Mande pair e~
monk couated here./ Pedg do gah es
oo a
ety , kl pete.
2ne~ = 6ne- => TYPES OF AROMATIC COMPOUNDS :-
+E 2N-electhon hupbtenn te
Tt follow (Un+a) mem Aybt en.
X Tf elecroms delacalized ».them compound .
Ohomatc
x yf electhoms localized , them compound mom
~ + ahoma tec.
* Comboumd will never be awh aromatic.
* eq . :
‘ @
° % = eS _ ae abe.
7 a Le pay
=() —> Amb-ahomatic.
‘ = Ls a Amb ahomatic:
eo
|
O > ©
eats 5 : < bis laceme nt of
: ma 2 taka place towands
Aromatic higher E-N- atom,
HE 4Ax electron hysten i
X Belongs to YNem bybtem (doesnt follow Huckel hule).
* rf electron. delocalized , them: comboumd i
amtiohomatic.
* If electhom not delocalized, them combound neve,
amtiaho-matic.
x if electhom, not deloélivea, cthem ‘comboumd © vy
mom- ahomatic. ——> Antaromatic.
# 6n-electom aurtem ;-
X Belomgh to (Un +2) Re- bubtem
x if electrons delocalized, them comoum d will be
onomatie.
x If electhomy does mot delocalized, them” comboumd
will be mom- ahomat.
eg
*
Ca /
° “on .
. OQ = Ahomatce.
+
CHa CHa
2 =
——> Ahomatc.
: L.\ —— Ahomahe
nN — Phomate.
—— Ahomatic.
rn CHa. ¢ ,
¢ :
. ‘
<— — Anomate:
° [ot Felco), ay LP. L), : 7
aie
Tat
: O->
: ENE biy them :
Aromatic:
X* Belomgh to YUnRe- kubtem.
* if electhoms delocalized,
anh ahomatic. “s
¥ If electron dowmot delocalized, them combsumd aut!
=,
V7
Ahomatic
Them comboum d will be be Mom drematic
cia
oe =O — > Nom -ahomatic.
Tub =
e ———>. Nom- ahomate.
° O — _ Antatomatic
+ Si Kelactno® bigabenn
x Beloman to (uaa) Ken system,
x If electrons delocalized, them corm bound will ee
aromatic.
x 1f elechows does not delocalized then comboumd
will be om -ahomatic.
x Compound will never be amk-chomatie.
\
° Cal —— Rebubsion between H~ atom , causes
the comboum J to be ~wom-blanan.
Now-animnale So, comboumd iy MOM~ Nhomah ¢.
done” bubbler
cyclizahon 'dgimng Dehudnogemation
aera \ \ doe
j. CRD.
See
i toner bydtem
Aromatic :
CO Ahonmatic -
(k= Gno)
Aromatic «
* Azuleme:— ;
8
i :
Ozw ene
CO- Oe
:
a Arulecoe WW the ihomer of ma thal
s Aruleme is lah blable them mabhthalen e.
& Azuleme gives eécthebhilic hubbtituton heachoms,
° Five membered “a ives hubsttuto~ negehom
of small Size 1 Henegetaty
G as Oe Sin
° DQ — & << CP € LS
— }
eo Like (same ) change smust beat maxivnuan” distance
amd opposite charge’ must be at: mikinnuin, distant:
fon dta Wty f hebomamce eae tana
2
+ 127 elechon hyrtern te
X Belomah to Un Rem bydtern . . ‘
x If electhows delocalized ,then Combound will. be AMAR omatic. web
¥ IF Clechowms doemol delocalized, them combound
will be mom- ahomatic:
* Comboumd will meyer be. chomatic.
(Nom blaw ah
ee Y
i Nom-ahomatic.,
oN,
\
g oy
Q f
CO ee Ww?
“ Aatonomatic i “ Amptohownatic ‘
ae
%. 49. Ne~ byslem (mam v7 flamah) sete. Dhomabic.
We BK Aromatic.
+e 14 x-electhom bybter
x Belongs to (Um+2).ne- Auster: oaghad x 1f electrons delocalised, then cownboumd wil be
Ohomatic.
X Tf dechows doe mot delocalized , then
will be mom ahomatic.
x The combound will mever be qmbohomate-
_
ogo
the coomboum d
Anomatic Ahom atic
Cos. oh
Anomatic on- ahomekic
Ahom ate
Vi
©@. Phemaleme wracidic inm matuke. Why 2
Pry. Photom (Ht) nemoved.fhom the phenalene amd
“ acidic .im .matuhe amd _dydterm qn ahoma ticity .
Sam
hom atic
(t4Ke- liplew)
# senzelectnon bysten Ss
% Belongs to YnRem huybtem,
¥ If electhons delocalizeds them cowboumd will be aint Ahomatic.
* 1 electhons doesm
:
ot delocalized , then compound
will be nom- aromak
x Comboumnd will never be ahomathc.
* eg
pahielded (high S-value),
Kntionomratic |
+F 18 x- electron Ay bteen so
x Belomarto (Un+2) Ker hubtenm,
it
X If electhows delocalized, them comboumd will be
Ohomatic. ;
¥ ae elechoms doe mot delocalized , them comb ound
will be ~nom- ahomatc. .
* Comboumd will mevei be amt Aomate, .
eed: : : "
Al nl b hrotoms highly dhielded .
: toy" 4
H
H
4 i r
H
[28] anmnuleme,
48% E> bubtem
Ahomatic.
* Combletel Com
j dm cli
jugate aprocye te
called ammuleme
bystew
© (18lammulene
Comtaims 3 cib clobe bond. ! Nom- ahomatic
4$ Other ohomatic hybterms :-
Fused hing ahomatc t- i
Triafulvaleme Caliceme
*
e Such tube of dydtemns mau be ahomatic oh
mom- ahomatic bul mever be amhahomahc.
. if huch tye of byplern eakomatic, then boty
himgh ~mubt be ohomatic after disblacememt of
common double bomd. Othenwike both him Kowill be
nom- ahomatc. . } a
. eg:
- + oN Lt
haho- Aromat A . . .
fees mat ¢ Ahomate Amb ohoma tic
overall byblem Nom - ahomatie.
xy or vabe | 1
+
Anti. Ant-
Ahomatic Ahomati¢ :
ahomatic Aromat ©
overall huyhten
Brom atic.
Anti
Aromatic
Aromatic
hom atic .
overall aybtem mom-oahomatc.
Arh atomatic
© Thoe bybtems which ae aromate ab a whole
heguine lowest em 4 bamnien for Rotating
around commom doultle bomd. “
“Thohe by bt erns, Which ohe
dhivinng force
will
Aromahe have
fora chahge he
they have combideha ble dipole
© Fused him Ohom atc hightemh he
dow emenay fon. ib | trams
° Tf along
Bamne, them
Qa
poration amd thus
omemt
quired helatvely
int eh Com Version:
ond, both “the bienah ahe
will always be Ohomatic.
Sy
Nom ~ah om atic
© Fon geomethical thomeham, the
amurt be hesbacted.
¥ Quabi_ahomahe cormboumds t=
© “Thhe ahe qeveally
oc
? Nu
A ENu
—
o
“+ HCLOy ——>
Jomic¢ ahomaht¢. commboun
c-C bond hotatom
OH ek
+ U0%
Quasi ohomat ¢
Commboumd
é e :
i sbré
A + SbFs ——>
8h, Q@uabi ghomat ¢
‘i Comboumd .
ae)
+ Age.
~~ me Quahi
aromatic
combo ound.
Q. Which of they Fotewiong ave ppt with Agnes?
F
o& 0G ob
Sli © amd ©: ,
o> & + Noy
+ agi — oe Ag@n ~
- Aahanomatic:
ise why mot give.
¥ Allotrobes of cahbom :—
Altotrobs of faabane
Diawom d Graphite Fullesene
pr if
Nom ahomati« Ahomatic , Anom atic
ives Jive
addition Addition
hum, haw, Dibemzeme
F hhoceme ji Chromium
: > Romatic.
Ahomahe omatic
% Meboionic ghomatic compound
0 Sydork B- the
bhow dhomatcty. why :
© Meo ionic Combounds give elechob MC Aubbhtu ton
heachomy. —
© Moho jomic. comb our ds are allo k/a
tht -mebo io mit éombound which
imtermal bath.
5 4e =
Jour? ae vw see
N St nee Taiyo}
Sgdom Dromatic
% Home ahomatc corm bourn da Bs
* comboumdn which combaim: om € OM “mone i bybhidised
Ceatomh in a Conjugate cycle but abs YeMdized
canblom alow ahe force. +0 hie almort vert call
a¥ove | the blame of the ahorm abic hystem kno ah homo aromatic comboum dh
. &9: Ha te
4 —
(_} + HiSoy —> Cs => fry,
© Wa
Howmatnobullitan
cation
PAI AIR I II
Note ;_
Umatable Emerau _, ( Stable )
Releae
(Now- arowmatic)—Chabge (Avowmatic )
Diamond _Chahge , Ghabhite SH = —ve
Graphite Pege , diamond OW = tVe
(Stable) 7 AA (Undtable).
gain
