Metal ion complex chelates

METAL ION COMPLEXS

CHELATES

BY:- SAKSHI CHANDAK

This is an index

5. CLASSIFICATION OF CHELATING AGENTS

1. DEFINATION

9. APPLICATIONS IN COSMETICS

10. APPLICATION IN OTHER FILEDS

6. CHELATION

2. LIGANDS

11. CONCULSION

7. MECHANISM OF ACTION

3. CHELATING AGENTS

12. REFERANCES

4. EXAMPLES OF CHELATING AGENTS

8. EXAMPLES

DEFINATION

• A substance containing two or more donor group i.e. ligands , may combine with a metal to form a special type of complex known as chelates.

• Some bond in chelates may be ionic or of the primary covalent type, whereas others are co-ordinate covalent links.

• Chelates always have the ring structure.

LIGANDS

Ligands are neutrals molecules or ions which are attached with the central metal ion . They are an ions or molecules that binds to a central metal atom to form a co-ordination complex.

Metal ion Chelate agents Metal chelate

CHELATING AGENTS

It is a substance whose molecules can form several bond to a single metal ion. A chelating agents is a chemical compound that react with metal ion to form stable, soluble complexes . Ex: ethylenediamine, oxalato ion, EDTA, etc

EXAMPLES OF CHELATING AGENTS

EDTA

CIT

DTPA

NTA

OX

P2O7 P3O10

CLASSIFICATION

When ligands provides one group for attachment to central ion, the chelate is called as monodentate.

Whereas, molecule with 2 and 3 called as bidentate and tridentate, respectively.

Ex: EDTA has 6 points as attachement to the metal ion and is accordingly hexadentate.

CHELATION

Chelation places stringent steric requirement on both metal and ligands. Ions such as Cu(II) and Ni(II), which form square planar complexes, can be exist in either of two geometric forms. As a consequence of this isomerism only cis-coordinated ligands-ligands adjacent on a molecule will be readily replaced by reaction with a chelating agent.

• Vitamin B12 and the hemoproteins are incapable of reacting with chelating agents because their metal is already coordinated in such a way that only the trans-coordination positions of the metal are available for complexation.

• In contrast, the metal ion in certain enzymes, such as alcohol dehydrogenase, which contain zinc, can undergo chelation suggesting that the metal is bound in such a way as to leave two cis positions available for chelation.

MECHANISM OF ACTION

• Chemical structure of chelates act like a hook to bind with metal ions.

• Forms heterocyclic ring structure by combining with metal ions.

• Reduce the propensity for oxidative reactions by removing metal ions from the solution.

• Act as antioxidant synergists, antimicrobial synergists and water softeners.

• Also enhance antimicrobial effectiveness by removing ions that support microbial growth.

They can be added to the water phase at any step in the production phase. When working with acid sensitive raw materials, it is recommended to dissolve it in water first and then add the appropriate substances. 0.01 to 0.5% of chelating agent is used in a specific formulation. It shows best performance at pH 6

EXAMPLES

• Chlorophyll and hemoglobin, two extremely important compounds, are naturally occurring chelates involved in the life processes of plants and animals.

• Albumin is the main carrier of various metal ion and small molecules in the blood serum.

• The synthetic chelating agent EDTA has been used to tie up or seqester ion and copper of ascorbic acid in fruit juices and in drug preparation .

*Seqestration, is the processes which chelating agent and metal ion to form a water soluble compound.EDTA is widely used to sequester & remove calcium ions from hard water

Applications in cosmetics.

VI

III

II

VI

• The chelating agents is preferably added to the soap saponification stage before finishing off to the desired pH.

• It 'grabs' metal ion that can affect the stability appearance of cosmetic products.

• Maintains foaming in rinse-off products when hard water is used & prevents precipitation of insoluble salts of fatty acids in soap.

• Some sunscreen agents require chelating agents to helps them to acheive a good shelf life.

• Chelating agents supports the protection of valuable ingredients from oxidation. (e.g. unsaturated oils, fragrance components)

• Discoloration and rancidity of lotions may be prevented by using chelating agents.

APPLICATIONS IN OTHER FIELDS.

IN INDUSTRIAL

IN PHARMACEUTICALS

in agricultural

IN CHELATION THERAPY

Chelating theraphy is the medical procedure that involves the administration of chelating agents to remove heavy metals from the body.

Chelating agents used for heavy metal removal from electroplating effluent.

Metal chelates compontents of fertilizer to provide micro nutrients.

Chelates complexes of gadolinium are often used as contrast agent in MRI scan.

conclusion

• A chelating agent is a chemical compound that react with metal ion to form stable, soluble complexes. The process in which chelating agent coordinated with metal ion is called chelation and the resulting complex is known as chelates.

• Examples of chelates used in cosmetic formulations are EDTA i.e. disodium edta and tetrasodium edta, citric acid, etc.

• Chelating agents are added in order to prevent oxidation, to maintain foaming, to stabilize in order to increase shelf life , to maintain the pH, etc.

THANK-YOU!

BY:- SAKSHI CHANDAK

refrences

Martin, Swarbrick, Commerate & cunn Physical Pharmacy Chapter 11. Page no. 270 & 271.

https://www.slideshare. net /MinalSainil/ chelatings-agents-and-its-application.

113-01519-01-cosmetics-toiletry-and-personal-care-uses-for-dow-chelating-agents.