The document discusses chelating agents, which are chemical compounds that can form multiple bonds to a single metal ion, forming stable, soluble complexes. It provides examples of chelating agents like ethylenediamine and EDTA. Chelating agents are classified based on the number of atoms that coordinate with the metal ion, and have properties like high solubility in water and low affinity for calcium. Applications of chelating agents include use in agriculture to provide micronutrients to plants, industrial uses like catalysis and metal extraction, and medical uses such as chelation therapy to remove heavy metals from the body. However, chelating agents can also have drawbacks like redistributing toxic metals or losing essential metals.

1. Chelating Agents and its Application
Presenation By
Beena
Rollno.
180000701011
M.Sc (P)

2. Contents
Introduction
Examples of chelating agents
Types of chelating agents
Property of ideal chelating agents
Appplication of chelating agents
Drawback of chelating agents
Conculsion
Referance

3. chelating agents
A Chelating agent is a substance whose molecules can
form several bond to a single metal ion.In other words
A chelating agent is a chemical compound that react
with metal ion to form stable ,soluble complexes.for
example ethylenediamine (en),oxalato ion,EDTA etc.T
he process in which chelating agent coordinated with
metal ion is called chelation .and the resulting complex
is known as chelates.for example

4. Example of chelating agents

5. Proteins ,polysaccharides and polynucleic acid are excellent
polydentate ligand for many metal ion .
Amino acid such as glutamic and histidine are typical chelators.
Porphyrin rings in hemoglobin and chlorophyll act as
Chelating agent.

6. Examples of metal chelates :

7. Types of chelating agents
Classfication of chelating agents made on the basis of
number of the atoms in molecules which coordinated
with metal ion. They are classified as
1.Bidentate ligands e.g ethylenediammime ,oxalato ion
2.Tridentate ligands e.g diethylene triamine, 2,2’,2”
Terpyridine (tery).
3.Tetradentate ligands e.g Triethylene tetraamine (trien).
4.Pentadentate ligands e.g Ethylenediamine triacetate
anion.
5.Hexadentate ligands e.g EDTA ,

8. Chelating effect :chelating effect is the enhanced affinity of
chelating ligands for a metal ion compared to the affinity of
non chelating (monodentate) ligand for the same metal.greater
the chelating effect greater will be stability of the resulting
complex. For example [cu(en)] have higher stability constant
than [cu(Me NH2)].
Some properties of an ideal chelating agent are
1. Highly soluble in water.
2. Low affinity for calcium .
3. form non toxic complex with toxic metal.
4. They are biologically inert.
5. More affinity for metals than the endogenous
ligand.

9. Applications of chelating agent
Chelating agents play an important role in many field discuss below:
1. In Agricultural : Metal chelate compound are common
compontents of fertilizers to provide micro-nutritents . The
micronutritents (Mn,Fe,Zn,Cu) are required for the growth of
plants .most fertilizers contain phosphate salts that in the absence
of chelating agents typically convert these metal ions into
insoluble solids that are of no nutritional value to the plants .EDTA
is the common typical chelating agents that keeps these metal ion
in a soluble form . Some of chelating agents can be applied
directly to the soil for root uptakes ,others via foliar sprays.some
are also well suited for use in soilless culture ,as there is no
formation of precipitates within the active ph ranges. Most
common chelates used in agriculture are EDTA,DTPA

10. EDDHA

11. • in extraction of metals : chemical weathering is attributed
to chelating agents e.g.peptides,sugars that extract metal
ions from minerals and rocks.
Chelation solvent extraction an example of pre treatment
techique for metal ions from aqueous sample (e.g
sea water )
• in oils production : in oil field chelating agents are
used in stimulation treatment and for cleaning surface
facilities . Typical oilfield chelating agent inclued
EDTA,HEDTA (hydroxyethylenediamine triacetic
acid),NTA (nitriotriacetic acid) and citric acid.

12. 2. In industrial field :
• used as catalysis :
Homogeneous catalysts
are often chelated complex.
For example BINAP (bidentate
Phosphine) in noyori
Asymmetric hydrogenation .
And used in manufacture of
Synthetic (-)- menthol.

13. Noyori asymmetric hydrogenation : it is a chemical reaction for
the enantioselective hydrogenation of ketones ,aldehydes and
imines.

14. Preparation of synthetic (-)- menthol

15. • chelating agents used for heavy metal removal from
electroplating effluent.
• chelating agents used to soften water in soaps and
detergents .e.g citric acid .chelation has little effect on the
water ‘s mineral content ,other than to make it soluble.
citric acid

16. • Dental application : detin adhesives system were based on
a co-monomer chelating ligand with calcium on the surface
of the tooth and generated very weak water resistance
chemical bonding.
• pharmaceuticals application : chelate complexes of
gadolinium are often used as contrast agents in MRI scans.
Penicillamine which form chelate complexes of copper is
used in the treatment of wilson’ s disease. Antibotic drugs of
the tetracycline and quinolone families are chelates of
Fe2+,Ca2+ and Mg2+ ions .

17. • in chelation therapy : chelation therapy is a medical
procedure that involves the administration of chelating
agent to remove heavy metals from the body.
There are number of chelating agents which used as drugs against
heavy metal poisoning in chelation therapy :
Ligand type of poisoning
Dimercaprol arsenic ,copper
EDTA derivatives lead
Succimer lead ,arsenic,mercury
Penicillamine gold toxicity ,copper ,lead,
mercury
Trienrine copper
Deferrionamine lead

19. Drawback of chelating agents
1.Redistribution of toxic metal
2.Essential metal loss .
3.No removal of metal from intracellular sites .
4.Poor clinical recovery .
5.Pre –oxidant effect (DTPA).
6.Increased blood pressure ,headche,nausea.

20. Conculsion
chelating agents are important in medical
,industry,agricultural,in bio chemistry and in other field.
Chelating agents form stable complexes with metals
Ion. But in chelation therapy they have some adverse effect
like burning on part where injection given,headche ,kidney
issuses.Nitrilotriacetic acid (NTA)
,ethylene diamine disuccinic acid (EDDS),iminodisuccinic
acid(IDS) are most commnly used biodegrable chelating
agents in place of non biodegrable agents EDTA,DTPA.

21. Reference
1. https : // pubchem. ncbi. nlm. Nih.gov
2. https : //en. Chem.station.com
3. https : // en.m.wikipedia org
4. https : // chem. Libertexts .org
5. https : // www.elsevier .com