pitz? Asts1
nit,
Lewis Acid - Lewis Base
period
ceptor (etcrete
r
uB
a
EN
"it> He? Hi:
Molecular Orbital Theory
orbitals
Atomic
Lewis Acid - Lewis Base Interaction
combine
to
form
Mo's
Anti-Bonding MO
(A
LA
LB
t
:B
*
BF3
IzB
NHz
t
LB
Ge-
:NAy
e-
Hypovalent
(C-deficientspecies)
molecule
W
1S
H
I'
-
Metal
Cations
Nat, Alst,
Mg2+,
having
Int
to
3rd
vacant
period
or
d-orbital
(species
withcentral
atom
below)
belonging
a
~
xe-deficiency
lewis
BeCIG
CCly
+4
+2
Silly
BE, Y
Y
·
BEz
Lewis Acid
-
~
Bond
L
I
Sich
+4
+3
2
os
<
BBs
ofcentral
atom
12
not
<
BIg
a
I
2
na=
no
->
atom
(Due
to
back
All
bonding)
NO
odd
for
tendency (same group
size
of
LB
no
[7
-
in
of e-present
BNO
in ABM
Bonding Mo
Stability
length
e-species
(nb na)
ofe-present
(pairede-)
cunpaired e)
LA
2
donation
no
=
Magnetic Behaviour
Comparison of Lewis Base Character
electron
Is
nb
Y
ofsurrounding
Er
H
Paramagnetic Diamagnetic
BeCIa> CCly
Exception:BF, <B11y
↳B a
ABNO
order=1
Energy
Bond
the
Bond
15
stability ofbond
Bond
strength
Comparison of Lewis Acidic Strength
·
I
-15
Bo
·species
in
stability
<
stability
Betz, BeClz, BE, AICly
(60-7
<4 3
(ye-) (6e7
·
in BNO
Adduct
Types of Lewis Acid
·
e-
is
100-
ofc-<14
and let
Paramagnetic
-
No
a
~*
2Pz
a
*cpu
nex 14
* 2py
~*
2Pz
a
21
D
2p
·
* 2py
↓
Trick
2s*
2
25
Trick
7
x
Ne-x 14
2121
*is*
is
0
25
"est
2s
(x2py xcpy)
%<pz
=
(**2px x*2py)
Ys
*2P2
*
=
-
2p
jxzy
2p
*2Py
25
BNO
ABNO
I
t
·
1S
IS
+ ye
-S
02:He-
2121
2 -7
r
t
B
⑧
ris
2
1221
2Pz
x 2 Px
*
*cpu
e
overlap
ve
-
8x2ee
15
overlap
=
2
~15
↑
s*
-
is
=7
is
*is*
2s
(12px x2py)
(x24 xEy)
=
=
-
(F2n x2py)
Fiz
"est
=
(* px
2Pz
*
2Pz
x*py)
=
*22
=
*
-
30
1(1)
=
-
na)
I(10
=
-
1) 2
=
Trick
·
If
eis
added in
BMO
OR
e-
is
removed ABMO
B0
+
0.5
↑
·
Ifeis
added
Cg.
82
in
ABMO
(150)
Bond
Bond
&
02(14e-) 3.0
1.5
02(180-)
-
↑
=
02's02 02 O
length:OO:*** On 0
-
hybridisation
sp
0.5
1.0
=
>
order:
"
02
Eg. Becke
Be
honge)
(Titue
12
bonds bane
hate
unpair
↑I
Krane
180
X
I
Ch
G.S
C
2.5
B0
BMO
Bu
Hybridisation
C
from
removed
=
=
02(17e)
stability
is
or
252
-
Es
2p2
1
1!
25
24
·
1
↑
v1L
* L
↑L
H
H
H
only for species
Quotient
Ch
spsp
sp2
B
sp3
bond
hybridisation
->
↑
↑W
2p
25
↑
↑
single
central
with
pain
Consider
B
atom
Fe's
->
-
A
2p
25
sp3
Truck: Valid
B2
I
T
↑
sp2
H
F
120B
Total valence
e's in molecule
Trigonal
F
Remainder
2
2
Sp
lone
↑L
pair
&180
Linear
12
AV
120'
3
4
sp2
sp3
Trigonal
Planar
Tetrahedral
-
sp3
710928'
CH4
C
Es
5
6
F
sp'd
sp3 d
sp3d
TBP
1203790
octahedral
Pentagonal
Bipyramidal
hybridisation
I
ii. "
or
or
I
I
or
i
in
12
!
I
10928"
.......................
sp3
72
M
-
Tetrahedral
(non-planar)
I
Planar
hybridisation
sp3ds
hybridisation
sped
PC15
P
*
↑L
4
*
(eqbond/xanial
I
3d
GS
i
P
35
.
-
.
4
-
-
.
.
-
so
Cl
.
. I
-
Ch
P
Cl
equatorial
(P-(1) car
·
enternal
become
and
longer
of11
atoms the
anial bond
shell electron
this
assumed
to be
formed by
the combination
of
Ch
&
CL
Px
+
+
(stPutBy+day dazy)
+
Pair
=
-
-
=
Py)
2
de
·
sp3d
SFG
hybridisation
-____,#All positions
sp3d
i
s+pn+ py+daryz
............
Pz, d2
octahedral
If
a
will be
are
same
geometry.
in
eg.
contains lone
molecule
different
CH4
sp3
and bond
te
!
N
Tetrahedral
. . . . . . . . . .
valence
Ifthe molecules contain no lone pair and all the bonds are
ofsame type then, it will have the same geometry
as
produced by hybridisation
·
((s
orbitals withlobes
formedbow the axis
lying blow the anis will be
be
·
°z
P
to
the
-
It is
assumed
x
equitorial.
than
be
repulsion Theory (VSEPRT)
Acc,
different pairs present in the
theory
central atom exert
shell of
repulsion over each other.
Repulsion blu different e-pairs follows the order
Ip-1px (p-bp bp-bp
As no of
bond, repulsion o
(E) (=)> ( ) ( 3x(-) (-)
Valence
to
repulsion blue pairs
the
((,dzz)
->
CL
minimise
can
used
L
120
sp3d
To
Bonds
CL
anial
spd
p-canial"
-90
2
->
---------.3d
,-3p..
--
...---
F7
Pyramidal
1070
LH -C-H 10928' (HNH=
=
Hy0
pair
angle
then
its
also
geometry
sp3
Co
H
Bent-shape
104.59
KHOH=
Bond
Angle
reputsion
ofactual geometry
Determination
Determine the
·
and
calculate
·
Draw the
·
Place
by's
on
central
the
atom
hybridisation.
geometry
pair
and
as
H
predicted by
multiple bonds
and
at
consider the
will be the
actual
lone
in
pair
shape,
the
shape ofmolecule
repulsion
(sp) -> linear
->
BeCl, CO2
are
call positions
of H0 2
2pp+0lp
2) no of Ho =3
no.
=
36p
·
0lip
+
remaining
no. of
4)
·
3)
no
(Bent
eg. SO2
o
·
S
0
H
C
lip
10928'
H
CL
I
P
-
--+
LFSF
I
F
3bp+ 21.p
etc.
Ch
F
2bp+
·
Tetrahedral
T-shape
F
:
I
3P
XeFe
"
-2
linear
(180) Planar
"
I
H
-
E
CHy, CCly, Silly
Ion-planar)
r
F
B
+
Ch
planar
F
.
of10 =4(sp3)
4bp
·
non
I
·
③
olp
4bp+4p (SFy)
F
A
120
+
(sp3d)
5
=
TBP
Ch
Ch
Az
1
HO
Ch
equivalent)
·
2bp 1." Ip
5bp
angular y-shaped
or
H
H104.50
Ch
·
bent
eg:BC1s, Allly
CL
yes.
angle
bond
2lp
+
Co
B
Ch
=
up-bp repulsion,
4
H
2bp
&
is
107
N-H
-
Trigonal Pyramidal
hybridisation.
manimum
i
<H
N
·
not
Do
ofIp's
its
same
lone
position.
·
no.
(hir,
36p+1c.p
·
->
+
·
sp3d
6bp + 0lp
E
F
F
->
SF6
S
F
F
F
790
5bpt
·
*s
⑳***I⑦
Bis
3.p
↑
Bent rule
"If
a
F
F
Be
·
4bp
+ 2
1.p
I
-e
%.S-character ofthe orbital"
Angle
with
SY2
s
strong repulsion blw up-L.p
and
Ifhyb
1p
x
repl
2
104
B
·
B
⑰
If hybridisation
is
same
up
and
(ioz.) 1909.
is also
Bent Rule
Electronegativity
EN
15
sp>
50%
Greater
and
are
of
sp2
33.33%
the
higher
orbital
an
be
for
throughsingle
will bond
preferably
a
its
closer
more
will
orbital
to
BA
in which
bonds. The element
having
surrounding
having
lows
more
character
atoms
are
electronegativity
(low EN)
win
of
Bulky
H20
(120
surv
atom
0
X
~ 2
CH3
size
2
~ 2
ja
nucleus
electronegativity.
molecule
withorbitals
be the
diff
biff SA
25%
will
bonded
%s-character
sp3
x
ys-character
Acc. to Bent Rule
2
-
2
H
CH3
steric hindrance
AD
U20
x FzO
Y
H2O
-3
H20. NHy <CHy
BA
not exist
molecules does
p3
pair
31
I
2
CCly
(109:28')
(120)
lone
same
be
S-character.
Belly BC1Y
1
(180)
very
up-bp,
-
orbital
will
possible
due to
⑬
an
multiple bonds
always
S⑦④π?).
orbitals
y.
repulsion
not
is attached to
and
x
BA
F
sip
a
Bond
Planar
Square
F
·
pair
present in
F
the
as
high
lone
non-planar
① 2
·
stated
be
atom
EN
more
it will decrease
pyramidal
square
E
E
also
can
H
of
(A
SA
same
Valence Bond Theory
long
Attraction
Repulsion
Range
............
H
Anis passing
fora teeof sen
H..........
H
Inter- nucleic Anis
INA
--------
--
the
orientation
and
shape
through
nucleus.
orbitals
ofatomic
H
spherically symmetrical
s-orbital:
H
H
t
CA
&B
-
I
t
5
Attractive force
I
t
NA
NB
force
NA- eB
NA-
NA-CA
CA
B
B
A
Repulsive
AB
B)
Up
-
-
C
at
pt
-
These
dominates
Repulsion
dominates
Attraction
-
are
eB
attraction
B:
these
NB
are
not
charges,
signs ofwave
p-orbital
Repulsion
↓
my
↓
e-wave
-
nodal
orbitals
nature
+
manimum
bow
will become
bondednuclei
plane
other
->
formationblu
-> one
unpaired
e-each
vacant orbital and
filled
"whichprobability
-
is
zero.
42=0
↓-orbitals
·
one
plane
two atoms
by overlapping of atomic
having
in
of finding
orbitals
e-density
the two
each
function(4)
occurs
a
overlapping
wave
into
atoms
Bond
As result of
the
oftwo
nodal
z
↓
uZ
yz
opposite sign ofwave function
P2
py,
il
B
Concept ofoverlapping
The
penetration of atomic
bothlobes have
dumb-bell shape
pu,
function
one
fully-
·
double
opposite
dumb-bell
lobes
have
samesign
orbital.
>
of
wave
functions.
plane
Types of Overlapping
1)
·
Anial/Head
When the
on
orbitals
overlapping
overlap
withtheir
ercloud
anis.
·--bond
are
formed
due to anial
overlapping.
lying along the
intermolecular
As p-orbitals
(i.e lobes lie
directionally
are
in
extentwill be
a
direction)
certain
higher
Y
esseplup
For differentshells
also
<
2p<bp
<
15-25
Is-Is
3s.....
up......
As
bondstrength
a
Entent
ofoverlapping
strength of
2
boud
comparison
S-S
⑦
oft-bonds
s
-p
S
p p
D
-
overlapping
number increases size
Y
23-25
y
1s-3p
X
comparison ofand
a
of
oforbital
bond
35-25
35-35
15-4p
up-up
strength
⑳
68
Inter-nuclear
-
repulsion
orbitals increases, the internuclear
also yes and
effective
3p-3pX
sp-2px
5
and
the
shell
same
the size
distances
23-25
x
Is-2py
comparison of
so
res.
<25
Is
For
As the shell
->
concentrated
more
Y
hence
overlapping becomes
less
Fajan's Rule
to
compounds
is
Application
100% conic
or
100% covalent
②
·
·
covalentnature
covalent
charge
&
nature
cation
a
size
·
on
Polarising power
polar
If
·
ofcation
in
=
Met FO
a
molecule
Covalent(
&
Mnet 0
non-polar
Unet=
molecule
bonds
all
does not
contain
lone
o
and the
pair.
CL
Cl
Ch
C114
C
B
CL
CL
CL
same
are
B(ly
Unet
0
=
Cl
Becky, P115, B11s, CCly, SEg
Muet=0
contains
or diff
molecule
the
up
If
types ofbond then
Met may or may not be zero
302
i
S
1
CD
O
H
Mnet FO
xkt
Lit Nat
Lit
Polar
<Ng2+
(Nat
CovalentCharacter
Fajan's Rule
lill*MgCl< AIC,
d
Dipole Moment(U)
u
qxd
=
>
-
I
distance
q
↳
Charge
Unit:Debye
1D 3.33 x
=
10-30 (m
-
q
Representation
Cl
-
Less
EN
EN
Y
move
ENH
EN
H
Unet FO
Polar
CL
Ch
20
-
Co
H
-
Polar
Unet FO
lattice
Energy
Energy required,
Nat
(g)
(1
+
when
-
mole
I
(g)
of
an
NaCl
Energy required
↓
1. E
Ifa
largee
LiCk<NgCy AICIs
(s)
ionic lattice
is
formed from
its
constituentions.