Crystal l Field Th heory-II - VP & RPTP Science College

1 | P a g

Dr Vip

Introdu Eve

kind

The

The

orbi

The

g e

ul Kataria

uction erything in t

d of geomet

e Jahn Telle

e Jahn Telle

itals.

e electrons d

If the electr

more attrac

referred as

If the elect

axis will h

and the phe

Jahn Teller

(here consi

, Chemistry

the world tr

try.

r effect is b

r effect obs

density is pr

ron density

ction hence

Z OUT.

tron density

ave more a

enomenon is

r effect is n

der t2g and

y Departmen

Crystal

ries to rema

ased upon s

erved due t

resent over t

is maximu

more repul

y is maximu

attraction he

s referred as

ot observed

eg as separa

nt, V. P. & R

l Field Th

ain in the st

same kind o

to asymmetr

the axis in t

um over z a

lsion results

um over x

ence more r

s Z IN.

d in half fill

ate orbitals)

R. P. T. P. S

heory-II

table form,

of phenomen

rical distrib

the orbital.

xis than lig

s into large

and y axis

repulsion re

led or fully

).

Science Col

By Dr

and for tha

non.

ution of ele

gands over t

z axis, and

than ligand

esults into l

filled elect

llege, VV N

r. Vipul B.

at it adapts

ectron densi

the z axis w

the phenom

ds over the

large x and

tronic confi

Nagar

Kataria

to some

ty in the

will have

menon is

x and y

d y axis,

guration

2 | P a g

Dr Vip

Z

g e

ul Kataria

Definition:

electronical

energy of th

The Jahn T

orbitals par

Jahn Teller

in or out J

, Chemistry

A sponta

lly asymme

he overall s

Teller effect

rticipating in

r effect in oc

JTD Stron

y Departmen

aneous dist

etric system

ystem.

t can be stro

n occurrenc

ctahedral co

ng field No

nt, V. P. & R

tortion of

m which res

ong or weak

ce of distort

omplexes.

o. of Electro

R. P. T. P. S

geometry

sults when

k according

ion.

ons Weak

Science Col

for non-lin

levels are

g to electron

Field JTD

llege, VV N

near molec

split to red

n from the d

D Z in or o

Nagar

cules in

duce the

different

out

3 | P a g e

Dr Vipul Kataria, Chemistry Department, V. P. & R. P. T. P. Science College, VV Nagar

Z in W t2g1 eg

0 d1 t2g1 eg

0 W Z out Z out W t2g

2 eg0 d2 t2g

2 eg0 W Z out

--- --- t2g3 eg

0 d3 t2g3 eg

0 --- --- Z in W t2g

4 eg0 d4 t2g

3 eg1 S Z out

Z out --- t2g5 eg

0 d5 t2g3 eg

2 --- --- --- --- t2g

6 eg0 d6 t2g

4 eg2 W Z in

Z out S t2g6 eg

1 d7 t2g5 eg

2 W Z out --- --- t2g

6 eg2 d8 t2g

6 eg2 --- ---

Z out S t2g6 eg

3 d9 t2g6 eg

3 S Z out --- --- t2g

6 eg4 d10 t2g

6 eg4 --- ---

Jahn Teller effect in tetrahedral complexes.

No. of Electrons Weak Field JTD Z in or outd1 e1 t2

0 W Z out d2 e2 t2

0 --- --- d3 e2 t2

1 S Z in d4 e2 t2

2 S Z out d5 e2 t2

3 --- --- d6 e3 t2

3 W Z out d7 e4 t2

3 --- --- d8 e4 t2

4 S Z in d9 e4 t2

5 S Z out d10 e4 t2

6 --- ---

Tetragonal complexes or Jahn Teller effect

The main difference between tetrahedral and tetragonal complex is that in tetrahedral

complexes the angle between two ligands is 109˚ 28’. In tetragonal complex the angle

between two ligands is any other than 109˚ 28’.

The Jahn Teller effect owes to asymmetric electron configuration within the orbital

which causes higher energy for complex and the complex tries to distort to maintain

stability.

eg orbitals are equally degenerated while t2g orbitals are triply degenerated.

t2g orbitals have no role in octahedral complex formation hence it does not produce

any Jahn Teller effect as far as tetragonal structure is concerned.

In octahedral complexes, the six ligands join with the six lobes of eg orbitals.

eg orbital is consist of two orbitals (dz2 and dx

2-y

2).

4 | P a g

Dr Vip

Asymm

g e

ul Kataria

dz2 orbital h

If both the

any Jahn Te

If the eg o

tetragonal s

metric arran

If both the

remain emp

If both the

it will be as

As shown a

cases eg orb

dx2

-y2 orbita

lobes to wh

, Chemistry

has two lobe

eg orbitals

eller effect

rbital filled

structure is

ngement of

e eg (dz2 an

pty than it w

eg (dz2 and

symmetric a

above, in d

bitals filled

al has four

hich two lig

y Departmen

es and dx2

-y2

are filled sy

and regular

d asymmetr

formed.

f electron in

nd dx2

-y2) or

will be symm

dx2

-y2) orbit

arrangemen

4, d7, and d

symmetrica

lobes to w

ands attach

nt, V. P. & R

2 has four lo

ymmetrical

r octahedral

rically than

n eg orbita

rbitals are f

metric arran

tals are fille

nt that is resp

d9 systems,

ally.

which four

.

R. P. T. P. S

obes, to whi

ly or remai

structure fo

the octahe

als

filled with

ngement.

ed with diff

ponsible for

, eg orbitals

ligands atta

Science Col

ich the six l

n empty tha

orms.

dral structu

equal numb

ferent numb

r Jahn Telle

s are asymm

ach whilst d

llege, VV N

ligands join

an there wil

ure distorts

mber of elec

ber of electro

er effect.

metric in re

dz2 orbital

Nagar

n.

ll not be

to form

ctrons or

ons than

st of the

has two

5 | P a g

Dr Vip

Splittin

Splittin

g e

ul Kataria

Now if the

attraction t

repulsion th

(Z in).

If the elect

central met

from centra

In case of Z

axis becom

tetragonal

structure.

In case of Z

axis becom

elongated t

The distorti

ng of d orbi

Due to lig

among wh

If eg orbit

Energy of

decrease a

ng of d orbi

, Chemistry

electron de

towards cen

hat results i

tron density

tal ion and h

al metal ion

Z in, where

me short, it

structure. S

Z out, wher

me long. It

etragonal st

ion occurs t

itals

gand field e

ich energy

al filled asy

dx2

-y2 orbita

s it attaches

itals in squ

y Departmen

ensity remai

ntral metal

into increase

y is higher o

hence will g

compare to

e two bonds

t results in

Such tetrag

re two bond

t results in

tructure.

to get the m

effect in oc

of t2g orbita

ymmetrical

al will incre

s two ligand

are planne

nt, V. P. & R

ins higher o

ion (in cas

ed distance

on z axis th

get more rep

o x and y ax

s on z axis

nto distortio

gonal struct

ds on z axis

nto distorti

maximum sta

ctahedral co

al decreased

lly than fur

ease as it at

ds.

er complexe

R. P. T. P. S

on x and y a

e of d4 and

from centr

han dz2 will

pulsion that

xis (Z out).

become lon

on and oct

ture is kno

become sh

on and oc

ability.

omplexes, o

d and energy

rther splittin

ttaches four

es

Science Col

axis than dx

d d7) and he

ral metal ion

have more

results into

ng and four

tahedral str

wn as com

hort and fou

tahedral st

orbitals spli

y of eg orbit

ng occurs to

ligands and

llege, VV N

x2

-y2 will ha

ence will g

n compare t

e attraction

o increased

r bonds on

ructures dis

mpressed te

ur bonds on

tructure dis

its in to eg

itals increas

o achieve s

d energy of

Nagar

ve more

get more

to z axis

towards

distance

x and y

storts to

tragonal

x and y

storts to

and t2g

es.

stability.

f dz2 will

6 | P a g

Dr Vip

In resp

central

orbitals

(i)

Splittin

g e

ul Kataria

ect of octa

metal ion

s of metal io

eg group: (d

With refere

energy will

energy.

In a system

ligand field

Now, dz2 o

compare to

In presence

will increas

When energ

attach easil

of two elec

It causes ex

form in pla

ng of groun

, Chemistry

ahedral fiel

which prod

on loses its d

dx2 – y2 and d

ence to octa

l be higher

m having ei

d, t2g orbital

orbital has t

o dx2 – y2 as

e of strong

se in same a

gy of dx2 –

ly to it whil

trons.

xclusion of

ace of octahe

nd state term

y Departmen

d, ligand w

duces ligan

degeneracy.

dz2)

ahedral field

while t2g o

ight electro

l has six ele

wo lobes he

it has four

ligand field

amount to g

y2 increases

le dz2 will b

two ligands

edral.

ms

nt, V. P. & R

with its neg

nd field effe

. It causes s

(ii)

d eg orbital

orbitals (dxy

ons (d8), in

ectrons whil

ence there w

lobes.

d, energy of

gain stability

s the electro

be repelled t

s to form ge

R. P. T. P. S

gative char

ect. As a r

splitting of d

t2g group: (

ls (dx2 – y

2

y, dyz, and

presence o

le eg orbital

will be little

f dz2 will de

y.

on come do

the ligands

eometry and

Science Col

ge attacks

esult of thi

d orbital in t

dxy, dyz, and

and dz2) b

dxz) will be

of weak lig

has two ele

e repulsion

ecrease and

wn to dz2 a

attaching to

d square pla

llege, VV N

positively

is degenera

two groups

d dxz)

become exc

e stable wit

gand field o

ectrons.

for one ele

d energy of

and four liga

o it due to p

anner struct

Nagar

charged

acy of d

.

ited and

th lower

or strong

ectron as

dx2 – y

2

ands can

presence

ture will

7 | P a g

Dr Vip

g e

ul Kataria

Spectral ter

complexes.

Term symb

In ground s

orbital show

In case of g

Ligand fiel

In presence

a2g, t2g and

D term spli

A, T and E

d orbitals o

octahedral

In tetrahedr

Spin multip

on the left s

Splitting an

, Chemistry

rms are very

.

bols obtaine

state, s orbi

w seven deg

ground state

d does not a

e of ligand

d t1g.

its into T2g

are Mullike

of d1 and d2

field as belo

ral field the

plicity (2s +

side of term

nd order of e

y Departmen

y useful in

d by l-l cou

itals show o

generated la

e terms, S te

affect s & p

field, d orb

and Eg whi

en symbols

systems an

ow.

above split

+ 1) is obta

m symbol.

energy of sp

nt, V. P. & R

understand

upling are de

one, p orbit

ayers.

erm symbol

p orbital hen

bital splits i

ilst F term s

.

nd their spe

tting got rev

ained by S-S

pectral term

R. P. T. P. S

ding the spec

esignated by

tals show th

shows one

nce they wil

into t2g and

spits into A2

ctral terms

versed.

S coupling

ms are shown

Science Col

ctra of trans

y S, P, D, F

hree, d orbit

, P term sho

l not split.

d eg whilst

2g, T2g, and

2D and 3F r

and designa

n in followi

llege, VV N

sition eleme

F….

ital show fiv

ows three, D

f orbital sp

d T1g.

respectively

ated as sup

ing table.

Nagar

ents and

ve and f

D

plits into

y split in

er script

8 | P a g e


Term Splitting Order of energy of term

Octahedral field

Tetrahedral field

S A1g (one) A1g A1

P T1g (Three) T1g T1

D T2g (Three) + Eg (Two) T2g < Eg E < T2

F A2g (One) + T2g (Three) + T1g (three) T1g < T2g < A2g A2 < T2 < T1

Eg and T2g terms are again splits due to Jahn-Teller effect.

Term Splitting Order of energy of term

Octahedral field Tetrahedral field

Eg A1g (one) + B1g T2g < Eg Eg < T2g

T2g Eg (two) + B2g Eg < B2g < A1g < B1g B1g < A1g < B2g < Eg

Hole Formalism In dn and d10-n system of complexes, in presence of same ligand field splitting of Eg

and T2g spectral terms will be of reverse of each other. The phenomenon is known as

Hole-Formalism.

Spherical charge symmetry of d orbitals In d0, d5, and d10 systems electrons arrange symmetrically and such d orbitals are

termed as spherical charge symmetric structures.

Spherical charge asymmetric structures of d orbitals Apart from above mentioned systems, all the d orbital electronic structures have

different electronic distribution and are known as charge asymmetric structures.

Charge asymmetric structures and Hole formalitic pair

9 | P a g e


In dn and d5+n electrons are more than spherical charge symmetric structures so they

are known as excess electron systems.

In d10-n and d5-n electrons are less than spherical charge symmetric structures and

known as less electron systems or positive hole or positron system.

For example: d1 system one electron is more than charge symmetric structure while in

d9 system one electron is less than charge symmetric structure, that make one positive

hole or one positron system.

Such pair is known as Hole formalitic pairs.

The formalistic pairs are depicted below.

Hole Formalitic Pair Spectral term

dn d10-n

d1 d9 2D Doublet D

d2 d8 3F Triplet F

d3 d7 4F Quartet F

d4 d6 5D Quintet

Hole formalism and splitting of spectral term dn and d5+n are excess electron system and in complex formation ligands are attached

with metal ion by repulsion forces.

While in d10-n ligands attach with metal ion by attraction force.

Thus the d orbital (eg or t2g) of dn system with which ligands are attached their energy

increases due to repulsion while in d10-n system energy decreases due to attraction

forces.

Thus by attachment of ligands the spectral terms of dn system show increase in

energy, energy of same d orbital spectral term will decrease in d10-n system.

Thus in same ligand field splitting of spectral terms of dn and d10-n will be reverse,

such pair is known as formalitic pair. It has same spectral term with reverse splitting.

Example

Spectral term of d1 and d9 case is 2D, in d1 system in octahedral field energy of T2g

decreases while energy of Eg increases.

In d9 system energy of T2g increases and energy of Eg decreases.

For tetrahedral field, in d1 system energy of Eg decreases and energy of T2g increases.

10 | P a

Dr Vip

g e

ul Kataria

g is not use

It can be un

of d10-n in te

Similarly, d

, Chemistry

ed in tetrahe

nderstood th

etrahedral f

d2 and d8 ha

y Departmen

edral field.

hat splitting

field is same

as spectral te

nt, V. P. & R

g of dn spec

e.

erm is F. F

R. P. T. P. S

ctral term in

term splits

Science Col

n octahedra

as below.

llege, VV N

al field and

Nagar

splitting

11 | P a

Dr Vip

Orgel

g e

ul Kataria

Diagram

, Chemistry

m

y Departmennt, V. P. & RR. P. T. P. SScience Colllege, VV NNagar

12 | P a g e


The spectral terms of various inorganic complexes split in specific manner that can be

represented by various diagrams.

Tanabe-Sugano diagrams are of same kind but difficult to understand and interpret.

The splitting of spectral terms is important only in weak field and orgel diagram

represents same.

They are easy to understand and interpret.

Splitting of spectral terms and orgel diagrams In excess electron systems (dn and d5+n), ligand attaches to d orbitals by repulsion

forces.

In less electron or positron systems (d10-n), ligand attaches to d orbitals by attraction

forces.

So, in any field, spectral term for dn and d10-n will be same but splitting will be of

reverse.

Example

d1 and d9 has spectral term 2D.

In octahedral field for d1, splitting of 2D will be in Eg and T2g. energy of Eg will

increase and energy of T2g will decrease.

In octahedral field for d9, energy of T2g will increase and energy of Eg will decrease.

In tetrahedral field for d1, the energy of T2g will increase and energy of Eg will

decrease.

In tetrahedral field for d9, the energy of Eg will increase and energy of T2g will

decrease.

In same way, spectral term for d2 and d8 is 3F.

In octahedral field for d2, the splitting and order of energy will be T1g < T2g < A2g.

In octahedral field for d8, the splitting and order of energy will be A2g < T2g < T1g.

There is no effect of ligand field on S and P term as S is spherical and P has all the

degenerated orbitals.

The splitting of dn and d10-n spectral term is of reverse in same field. However it is

same in different field.

13 | P a

Dr Vip

Lapor

(A)

g e

ul Kataria

Orgel diagr

field.

Splitting en

rte Selecti

Orbital SeThe transit

Change in a

Orbital altransition i

allowed as

momentum

Orbital fortransition is

occurs in w

In orbital a

high and du

, Chemistry

rams are h

nergy of d o

ion rules

lection ruleion of elect

angular mom

lowed tranis called or

one electro

m is 1.

rbidden tras orbital for

which Δl = 0

allowed tran

ue to this sh

y Departmen

elpful to un

orbitals can b

e tron is only

mentum Δl

nsition: If

rbital allow

on moves fr

ansition: if rbidden tran

0 hence such

nsitions the

harp band is

nt, V. P. & R

nderstand t

be explaine

y allowed if

= ±1.

the change

wed transiti

from s orbit

f the change

nsitions. In

h transitions

e value of

observed in

R. P. T. P. S

the spectra

ed.

f the angula

e in angula

ions. For e

tal to p orbi

e in angular

transition e

s are orbital

molar abso

n uv spectro

Science Col

of complex

ar momentu

ar momentu

example, 2s

ital and the

momentum

element seri

l forbidden.

orption co-e

oscopy.

llege, VV N

xes in weak

um changes

um is ±1 t

s2 2p1 is

e change in

m is not ±1

ies d d tr

efficient (ϵ)

Nagar

k ligand

s by ±1.

than the

s orbital

angular

then the

ransition

is very

14 | P a

Dr Vip

(B)

(C)

If above

co-effic

Usually

g e

ul Kataria

In orbital f

low and du

Spin SelectThe spin of

The spin m

In other wo

Spin alloware spin allo

Spin forbidare spin for

SymmetryIf symmetr

transition.

states.

For exampl

If symmetr

forbidden tr

e three rule

cient (ϵ) is

y such subst

, Chemistry

forbidden tr

ue to this we

tion rule f electron sh

multiplicity s

ords, no. of

wed transitiowed transi

dden transrbidden tran

y Selection rry of groun

In other wo

le: transition

ry does not

ransitions.

es are obeye

very high

tances are d

y Departmen

ransitions, th

eak and broa

hould not be

should be sa

unpaired el

ion: If there

itions.

sition: if the

nsitions.

rule nd state an

ords, the sy

n like g u

t change du

ed during el

and due to

dark and attr

nt, V. P. & R

he value of

ad band is o

e changed in

ame in grou

ectron shou

e is no chan

e ΔS = 0 in

nd excited

ymmetry sh

ug and ug

uring transi

lectron tran

o this sharp

ractive.

R. P. T. P. S

f molar abso

observed in

n electron tr

und and exci

uld be same

nge in spin

n electron tr

state shoul

hould be di

g are sym

ition then s

sition then t

p band is

Science Col

orption co-e

uv spectros

ransitions. H

ited states.

in ground a

(ΔS = 0) th

ransition, th

ld be chang

fferent in g

mmetry allow

such transit

the value fo

observed in

llege, VV N

efficient (ϵ)

scopy.

Hence ΔS =

and excited

hen such tra

hen such tra

nge during

ground and

wed transiti

tions are sy

or molar ab

n uv spectr

Nagar

) is very

= 0.

states.

ansitions

ansitions

electron

d excited

ions.

ymmetry

sorption

roscopy.

15 | P a g e


Reasons for forbidden transitions Forbidden transitions are very common.

Spin forbidden and orbital forbidden transitions occur due to L-S coupling.

l values for ground state and excited states change due to L-S coupling hence orbital

forbidden transitions occur.

Orbital hybridization causes change in symmetry of the orbital (ug converts to g and g

coverts to ug) hence symmetry forbidden transitions occur.

Vibrational levels (V) and rotational levels (J) involves in transitional energy levels

due to higher amount energy that causes symmetry changes hence forbidden

transitions occur.

A weak band observed in uv spectroscopy due to forbidden transitions.

Sr. No.

Type of transition Molar absorption coefficient

Example

1 Spin allowed 10,000 [Ti(Cl)6]2-

2 Spin allowed and orbital partially

allowed

500 [CoBr4]2-

and

[CoCl4]2-

3 spin allowed and orbital forbidden 8 to 10 [Ti(H2O)6]3+

and

[V(H2O)6]3+

4 Orbital partially allowed and spin

forbidden

4 [MnBr4]2-

5 Spin forbidden and orbital forbidden 0.02 [Mn(H2O)6]2+

Absorption spectra for transition elements The metal salt and complexes are dissolved in appropriate solvent and radiation is

passed through.

Electron transition occurs due to higher amount of energy and accordingly absorption

spectra are obtained. The wavelength range is 200 nm to 2000 nm.

The graph of molar absorption or molar co-efficient against wave number or wave

length is plotted, and absorption spectrum can be explained.

16 | P a g e


Molar absorption co-efficient is also known as Extinction co-efficient. 𝜖 = 𝐴𝑐. 𝑙 Where, c = concentration of solution or molarity, and l = length of cell.

The intensity of absorption band depends upon value of molar absorption co-efficient.

Origin Crystal field theory, molecular orbital theory and ligand field theory are the useful

means to explain absorption spectra of transition elements.

In transition elements, d orbitals are degenerated in ground state.

However in excited state, degeneracy is destroyed and d orbital splits into two groups

(t2g and eg).

In octahedral complexes, energy of t2g is lower whilst in tetrahedral complexes

energy of eg is lower.

Now in presence of radiation, electron transition occurs from lower energy to higher

energy (t2g eg or eg t2g).

Due to such transitions, d d transition absorption spectra are obtained.

Intensity of absorption band The absorption bands for transition metal elements are weak, broad and asymmetric due to

following reasons.

d d transition are orbital forbidden as Δl = 0.

d d transition requires higher amount of energy so some vibration and rotational

energy levels are included.

d orbital is symmetric so the transition will be symmetry forbidden.

Due to Jahn-Teller effect, t2g and eg orbitals split again hence higher energy levels

are produced. So, 2 or 3 maxima are observed and the spectrum gets asymmetric.

The value for molar absorption co-efficient is very low (1 to 50 cm-1).

Certain transition metal ions show spectrum with higher intensity due to several other

electron transitions.

(a) π π* transition The non-bonding d orbital electrons of transition metal transits to π* anti-bonding

bonds of ligands.

17 | P a

Dr Vip

(b)

Absor

PositionPosition

Position

g e

ul Kataria

So, it does

So, such tra

Such transi

Mixed orbTetrahedra

In such ca

orbitals.

Now electr

allowed (Δ

So, it will b

rption speThe aqueou

When radia

Electron tra

Pl

n of absorpn of absorpt

n of maxim

, Chemistry

not fall into

ansition is k

ition has mo

ital transital complexe

ases, there a

rons transit

Δl = ±1 and

be laporte a

ectrum of us solution o

ation passes

ansits from

ot of A or ϵ

ption band tion band is

ma or peak

y Departmen

o category o

known as ch

ore intensity

ions es do not hav

are optimum

from d

g ug).

allowed tran

f Ti3+

of TiCl3 yie

s through so

lower energ

ϵ versus wav

found 2000

nt, V. P. & R

of d d or

harge transf

y and has hi

ve centre of

m chances

mixed orbi

nsition that y

elds [Ti(H2O

olution, cert

gy levels to

velength or

0 to 12500 Å

R. P. T. P. S

g g type

fer transition

igher ϵ valu

f symmetry

of having c

itals and he

yield intens

O)6]3+

ain wavelen

higher.

wave numb

Å.

Science Col

s.

ns.

es (1000 cm

.

combination

nce it is orb

se absorptio

ngth absorbe

ber will be a

llege, VV N

m-1).

n between

bital and sy

on band.

ed.

as follows.

Nagar

d and p

ymmetry

18 | P a

Dr Vip

A clear

PositionApart fr

Explan

2Eg -

2Eg -

2Eg -

Absor

g e

ul Kataria

peak is fou

n of shouldfrom main p

nation Electronic c

The spectra

[Ti(H2O)6]3

The energy

Now due to

The transiti

2B1g

2A1g

2B2g

rption speCu2+ in aqu

It represent

, Chemistry

und at 4920

der eak, one sh

configuratio

al term is 2D3+ is octahed

y of t2g decr

o Jahn-Telle

ions are fou

4920 Å

5740 Å

Peak do

ectrum of ueous soluti

ts d9 system

y Departmen

Å which is

oulder is fo

on of Ti3+ is

D.

dral comple

reases and e

er effect the

und as below

Å main peak

Å shoulder p

oes not obse

f Cu2+ on exist as

m.

nt, V. P. & R

uv region s

ound at 5740

s [Ar] 3d1.

ex.

energy of eg

e orbitals sp

w.

peak

erved

[Cu(H2O)6]

R. P. T. P. S

so colour of

0 Å.

g increases.

lit again.

]2+ and blue

Science Col

f complex is

in colour.

llege, VV N

s light viole

Nagar

et.

19 | P a

Dr Vip

Range

Position

2B1g -

2B1g -

2B1g -

g e

ul Kataria

According

The spectra

and intensiAbsorption

Spectrum is

It represent

n of maximPosition of

Shoulder is

Spectral ter

Energy of E

2Eg

2B2g

2A1g

, Chemistry

to hole-form

al term is 2D

ity of absorn spectrum o

s asymmetr

ts d d tra

ma and peakf maxima is

s at 11000 c

rm 2D splits

Eg decrease

13000 m

11000 s

not in v

y Departmen

malism the

D.

rption specof [Cu(H2O)

ric and broa

ansition and

k at 13000 cm

m-1.

s into Eg an

es and energ

main peak

shoulder pe

visible range

nt, V. P. & R

splitting pa

ctrum )6]2+ is betw

ad.

that is lapo

m-1.

nd T2g.

gy of T2g in

ak

e

R. P. T. P. S

ttern is reve

ween 15000

orte forbidde

ncreases.

Science Col

ersed in case

to 20000 cm

en transition

llege, VV N

e of d1 and

m-1.

n.

Nagar

d9.

20 | P a

Dr Vip

Absor

g e

ul Kataria

rption speNi2+ exist a

Range of sp

Main peak

Shoulder pe

The spectra3F is ground

, Chemistry

ectrum of as [Ni(H2O)

pectrum is 5

is at 25300

eak is at 14

al terms for

d state term

y Departmen

f Ni2+ 6]2+ and gre

50000 to 80

cm-1.

500 cm-1.

d8 system a

m and 3P is te

nt, V. P. & R

een in colou

000 cm-1.

are 3F, 3P, 1

erm for nex

R. P. T. P. S

ur.

D and 1S.

xt excited te

Science Col

rm.

llege, VV N

Nagar

21 | P a

Dr Vip

3A2g

3A2g

3A2g

g e

ul Kataria

3T1g (F)

3T1g (P)

3T2g (F)

, Chemistry

25300 c

14500 c

8700 cm

y Departmen

cm-1

cm-1

m-1

nt, V. P. & RR. P. T. P. SScience Colllege, VV NNagar

22 | P a g e


Important Questions Explain Jahn-Teller effect in detail.

Explain Orgel diagram.

Explain Laporte rule.

Explain absorption spectra on Ni2+, Cu2+ and Ti3+.

Explain hole formalism.

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Crystal l Field Th heory-II - VP & RPTP Science College

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Transcript of Crystal l Field Th heory-II - VP & RPTP Science College