4. IONISATION ISOMERISM-
The complexes having same molecular
formula but on ionization gives different ions
are called ionisation isomers and the
process is called Ionisation Isomerism.
For example-
[Co(NH3)5Br]so4 [Co(NH3)5SO4] +1 + Br-1
[Co(NH3)5Br]SO4 [Co(NH3)5Br]2+ + SO42-
5. HYDRATE ISOMERISM-
This isomerism is similar to ionization
isomerism and arises from replacement of
coordinted group by water. Water molecule
present in complex may vary in their
resulting complexes.
For example-
[Cr(H2O)6]Cl3
violet
[Cr(H2O)5Cl]Cl2
Bluish Green
[Cr(H2O)4CL2]Cl
Dark Green
6. LINKAGE ISOMERISM-
It is found in those complexes in which
the legand can coordinate with central
metal ion through more than one
atoms.
[Co(NH3)5 NO2]Cl2 & [Co(NH3)5ONO]
Cl2
For example-
7. COORDINTION ISOMERISM-
If cation and anion part of complex
coordinate with same number of ligand
then their may be exchange of ligands
between the two coordination spheres
which gives isomer known as
Coordination isomers and this type of
isomerism is called Coordination
Isomerism
9. COORDINATION POSITION
ISOMERISM
In the polynuclear complexes there
may be interchange of ligands
between the metal nuclei which
give arise to coordination position
isomer and the process is known as
coordination position isomerism.
10. OR
It is isomerism which arises due to
difference in distribution of ligands.
For example-
11. LIGAND ISOMERISM-
Some ligand can exist in more than one
isomeric form.
For example-
Di-amino propane can exist in
two forms
12. When these ligands are associated
into complexes then the complexes
are called ligand isomers and
process is known as ligand
isomerism
13. STEREOISOMERISM
This is due to the different relative positions of
the ligands . It is of two types-
1.Geometrical Isomerism (cis-trans)
2.Optical Isomerism (mirror image)
14. GEOMETRICAL ISOMERISM
Geometrical isomerism arises due to the different positions of the
ligands around the central metal atom. If two different ligands are
adjacent to each other then isomers is referred as cis form and if
ligands are opposite to each other then isomers is trans form.
cis/trans form exhibited by square planar and octahedral
complexes.
15. Square planar/Tetrahedral
complexes
1. Complexes of the type [Ma4], [Ma3b], and
[Mab3]
Do not show cis/trans isomerism because all
the possible arrangement of complexes are
exactly equalivalent
16. 2. Complexes of type (Ma2b2 ) show cis/trans isomerism
e.g.[Pt(NH3)2Cl2] , [Pt(NH3)2(NO3)2]
Pt
NH3 Cl
Cl
NH3
cis-isomer
Pt
NH3 Cl
Cl NH3
trans-isomer
17. 3. Complexes of type [Ma2bc] type shows cis/trans isomerism
e.g. [Pt(NH3)2ClNO2]
Pt
NH3
Cl
NH3 NO2
Pt
NH3
Cl
NH3
O2N
trans-isomer
cis-isomer
18. M[abcd] ±n type
4.Complexes of this type exist in three isomeric forms as shown
below
examples are [Pt(NH3)ClBrNO2], [Pt(NH3)2pyClBr],
[Pt(NO2)py(NH3)(NH2OH)]+, [Pt(C2H4)(NH3)ClBr]
Pt Pt Pt Pt
a
b
c
d
n+
a b
c
d
n+ a b
c d
n+ a
b
c
d
n+
(I) (II) (III) (IV)
19. 5.Square planar complexes containing unsymmetrical bidentate
chelating ligands: [M(AB)2]±n
AB is unsymmetrical bidentate chelating ligands containing A and B
are two end of the ligand.
e.g. [Pt(gly)2] where gly is NH2-CH2COO- (glycine ion), exist
following cis-trans isomers
Pt
NH2 NH2
H2C
O
O
CH2
CO
OC
Pt
NH2
NH2
H2C O
O CH2
CO
OC
0
0
cis-isomer trans-isomer
20. 6.Bridged binuclear planar complexes of M2a2b4 type
4. Geometrical isomerism is also shown by bridged binuclear planar
complexes of the type M2 A2 X4
e.g. [PtCl2 PEt3]2
Pt
Cl
Cl
Pt
Cl
PEt3
Et3P
Cl
Pt
Cl
Cl
Pt
Cl
PEt3
Et3P
Cl
Pt
Cl
Cl
Pt
Cl PEt3
Et3P
Cl
cis-form trans-form unsymmetrical-form
21. Octahedral complexes
1. Complexes of [Ma6 ],[Ma5b], and [Mab5 ] do not
show cis/trans isomerism because all possible
arrangements are exactly equivalent.
22. 2. Complexes of type [Ma4b2] and [Ma2b4] show cis/trans
isomerism,
For example- [Co(NH3)4Cl2]
23. 3. Complexes of type [Ma3b3] show cis/trans
isomerism.
For example- [Cr(NH3)3Cl3]
24. 4.Complexes of type [Mabcdef] exist
inn 15 different geometrical isomers .
For example-
[Pt(py)(NH3)(NO2)ClBrI] but only 3
stable isomers are formed
25. Example: [Co(en)2(NO2)2]+ and [Co(en)2Cl2]+
5.The complexes of the type [M(aa)2 b2] shows
cis/trans isomerism where aa means symmetrical
bidentate ligands
27. OPTICAL ISOMERISM OR MIRROR IMAGE ISOMERISM
When the solutions of complexes are place in the path of
plane polarized light, than light rotates its plane through
certain angle either to the left side or right side. This
property of complex of rotating plane of polarized light is
called its optical activity and the complexes possessing
this property is said to be optically active.
33. Optical isomerism in Tetrahedral complexes:
Mirror image isomerism is not possible tetrahedral and
square planar complexes of type [Ma4], [Ma3b] and
[Mab3].
35. Optical isomers are known for the complexes of Be(II), Zn(II) and B(III) with
unsymmetrical bidentate ligands have been made and show optical isomerism
Example: [Be(C6H5COCHCOCH3)2]
In above complex no centre or plane of symmetry and are not superimposed on
each other. So it will give d- and l- form.
