Structure Benzene
of
f
n c c M
Cotes
n c c r
hexagonalplanararrangement
h
6 P orbitals
ff
delocalised
I system
Eachcarbonhas an electron in orbital delocalised e
p
that is not bonded make it morestable
f
electrons can overlap to
p orbitals containingthese form a T delocalised
system
electrons aboveand below the the
of electrons to move
free
plain of main
anywherearound the 6carbon
ring
Kekule structure
Originally
benzene thought to have 3 c c e 3 c C
re e c n
n e
dy
n
However delocalised TI system more appropriate
Bond lengths in benzene allsame length
not the case for 3 C C 1 3 C C
C C in 120kJ moi so
Energy required to break a youwould expect
benzene to be 36045 mol 3 C c
however this is not the case as it is 208KJ not dueto the stability
the T delocalised electrons
systemof it
gives
, Properties
of Benzene
obtainedfromcrude oil
colourless
liquid
Delocalisation means e are spread overseveral atoms
bonds between carbon 1 hydrogen are bonds
sigma o
addition runs easily due to TC delocalised system
Doesn't undo
Doesn't reactgo
of é
readily with
bromine
wonder electrophilic substitution an
goes
10H CMS NH2
O O O
Carson Censchs GMsNHz
phenol benzene
methyl phenylamine
11 Br COOH
o
Cohst CongBr Congloom
iodobenzene Bromoberare benzoic acid
Nor
v02
3
Ecn
CohsCooch Ghg002 NOCHLooks
methyl benzoate nitrobenzene methyl3nitrobenzene
of
f
n c c M
Cotes
n c c r
hexagonalplanararrangement
h
6 P orbitals
ff
delocalised
I system
Eachcarbonhas an electron in orbital delocalised e
p
that is not bonded make it morestable
f
electrons can overlap to
p orbitals containingthese form a T delocalised
system
electrons aboveand below the the
of electrons to move
free
plain of main
anywherearound the 6carbon
ring
Kekule structure
Originally
benzene thought to have 3 c c e 3 c C
re e c n
n e
dy
n
However delocalised TI system more appropriate
Bond lengths in benzene allsame length
not the case for 3 C C 1 3 C C
C C in 120kJ moi so
Energy required to break a youwould expect
benzene to be 36045 mol 3 C c
however this is not the case as it is 208KJ not dueto the stability
the T delocalised electrons
systemof it
gives
, Properties
of Benzene
obtainedfromcrude oil
colourless
liquid
Delocalisation means e are spread overseveral atoms
bonds between carbon 1 hydrogen are bonds
sigma o
addition runs easily due to TC delocalised system
Doesn't undo
Doesn't reactgo
of é
readily with
bromine
wonder electrophilic substitution an
goes
10H CMS NH2
O O O
Carson Censchs GMsNHz
phenol benzene
methyl phenylamine
11 Br COOH
o
Cohst CongBr Congloom
iodobenzene Bromoberare benzoic acid
Nor
v02
3
Ecn
CohsCooch Ghg002 NOCHLooks
methyl benzoate nitrobenzene methyl3nitrobenzene
