This document discusses isomerism in coordination complexes. It begins with an introduction defining isomerism as compounds with the same chemical formula but different structures. It then describes four main types of isomerism in coordination complexes: 1) Structural isomerism which involves different arrangements of atoms or groups. 2) Ionization isomerism which involves complexes that give different ions in solution. 3) Hydrate isomerism which involves the replacement of coordinated groups by solvent molecules like water. 4) Ligand and linkage isomerism which involve isomers resulting from differences in the ligands themselves or the connectivity of ambidentate ligands. Examples are provided for each type of isomerism.

1.  Name : Dhopare Jyoti Tarachand
 Roll No.: R1933305
 Course : S.Y.B.Sc.B.Ed
 Subject : Inorganic Chemistry
 Subject Teacher: Prof. Sudarshan Tapsale
 Topic: Isomerism in coordination complexes

2. CONTENT
 Introduction
 Types Of Isomerism
 Structural Isomerim
 A) Ionisation Isomerim
 B)Hydrate Isomerism
 C)Ligand Isomerim
 D) Linkage Isomerim
 Summery

3. INTRODUCTION
 Isomerism is the phenomenon in which more than one compounds
have the same chemical formula but different chemical structures.
Chemical compounds that have identical chemical formulae but differ
in properties and the arrangement of atoms in the molecule are called
isomers. Therefore, the compounds that exhibit isomerism are known
as isomers.

4. TYPES OF ISOMERISM
 Structural Isomerism
This type of isomerism is due different possible arrangment of atoms or
groups in their molecules.
 Example : 1-PenteneCH3CH2CH2CH=CH2
2-Pentene CH3CH2CH=CHCH3

5.  A) Ionisation Isomerism : This name is used to describe isomers that
give different ions in solution.i.e.in other words,two cordination
compound which differ in the distribution of ions between those
directly coordinated and counter ions present in the crystal lattice are
called Ionisation Isomers.
 For example, when pentaamminebromocobalt chloride is dissolved in
water, Cl−ions are generated:
 CoBr(NH3)5Cl(s)→CoBr(NH3)+5(aq)+Cl−(aq)
 whereas when pentaamminechlorocobalt bromide is dissolved, Br ions
are generated:
 CoCl(NH3)5Br(s)→CoCl(NH3)+5(aq)+Br−(aq)
 Notice that both anions are necessary to balance the charge of the
complex, and that they differ in that one ion is directly attached to the
central metal, but the other is not.

6.  B)Hydrate Isomerism:A very similar type of isomerism results from replacement
of a coordinated group by a solvent molecule (Solvate Isomerism), which in the
case of water is called Hydrate Isomerism. The best known example of this
occurs for chromium chloride (CrCl3⋅6H2O) which may contain 4, 5, or 6
coordinated water molecules (assuming a coordination number of 6). The dot
here is used essentially as an expression of ignorance to indicate that, though
the parts of the molecule separated by the dot are bonded to one another in
some fashion, the exact structural details of that interaction are not fully
expressed in the resulting formula. Using Alfred Werner’s coordination theory
that indicates that several of the water molecules are actually bonded directly
(via coordinate covalent bonds) to the central chromium ion. In fact, there are
several possible compounds that use the brackets to signify bonding in the
complex and the the dots to signify "water molecules that are not bound to the
central metal, but are part of the lattice:
 [CrCl2(H2O)4]Cl⋅2H2O: bright-green colored
 [CrCl(H2O)5]Cl2⋅H2O: grey-green colored
 [Cr(H2O)6]Cl3: violet colored

7.  These isomers have very different chemical properties and on reaction
with AgNO3 to test for Cl− ions, would find 1, 2, and 3 Cl− ions in
solution, respectively.
 Ligand Isomerism:Isomeric coordination compounds are known in
which the overall isomerism results from isomerism solely within the
ligand groups.
 An example of such isomerism is shown by the ions, bis (1,3
diaminopropane) platinum (2+) and bis (1,2 diaminopropane)
platinum (2+),

8.  D) Linkage Isomerism:Linkage isomerism occurs with ambidentate
ligands. These ligands are capable of coordinating in more than one
way. The best known cases involve the monodentate ligands SCN- /
NCS- and NO2
- / ONO-.
 For example: [Co(ONO)(NH3)5] Cl the nitrito isomer -O attached
[Co(NO2)(NH3)5] Cl the nitro isomer - N attached.

9. Ligands That Can Form Linkage Isomers
Ligand
Lewis
Structure
Name donor
Atoms
CN- cyanide ion C or N
SCN- thiocyanate
ion
S or N
NO2
- nitrite ion N or O
Linkage isomers are two or more coordination compounds in which the donor
atom of at least one of the ligands is different (i.e., the connectivity between
atoms is different).
This type of isomerism can only exist when the compound contains a ligand
that can bond to the metal atom in two (or more) different ways. Some ligands
that can form linkage isomers are shown below.
Linkage isomers have different physical and chemical properties.

10. Thank You