metal ion catalysis.pptx

A detailed example of metal ion catalysis an enzymatic catalysts and water Ph catalysts morover the catalyst of about today's demand, and catalytical discoverises, catalyst in human body haemoglobin, a brief outline on catalyst demand and working, a most use of catalysts, catalysis, catalyst in haber process, catalyst meaning, a IT usage of catalysts

1. METAL ION CATALYSIS By SAMEEN FATIMA ROLL NO. 908529

2. CONTENT METAL ION CATALYSIS (A bit introduction) EXAMPLE CLASSES METAL ION OR ELECTROSTATIC CATALYSIS - STABILIZATION OF ITS CHARGE METAL ION CATALYSIS WTH COMPLETE ORIENTATION METAL ION CATALYSIS - DECREASING pKa OF WATER DISADVANTAGES EXAMPLE OF PLATINUIM ION CATALYST

3. METAL ION CATALYSIS Metal ion catalysis is also called electrostatic catalysis. It is a specific process or reaction in which metal ions are used to enhance the reactivity of a reaction. In this process some metalloenzymes are used to go on a catalytic pathway in this reaction same metal ions i.e.: Fe2+, Cu2+, Zn2+, Mn2+, Co3+, Ni3+, Mo6+ etc. are used. [1] Almost 1/3 enzymes from the known percentage of enzymes are worked on the metal ion catalysis process . [2] Metal ions always act as a complex system with the reactant while doing the catalytic process . And also called the Lewis acids.

4. Examples Here the metal ion act as the electrophilic catalyst. Hemoglobin is an honorary enzyme . Oxygen binds to the iron in the heme, forming an octahedral iron complex. This form is called oxyhemoglobin; the form without the bound oxygen is called deoxyhemoglobin. [3] d+ means partial positive

5. [4] Here the metal ion act as the metal ion acted as the catalyst and formed complex system. The catalyst is Lewis acids . [5]

6. METAL ION CATALYSIS - DECREASING pKa OF WATER [6] For instance, the water molecule in the pentammineaquacobalt(III) ion has a pKa of 6.6, compared to pure water, with a pKa of 15.7. (To calculate the latter, write the equilibrium expression for water: H2O + H2O <==> H3O +  + OH -  . Then write the Ka expression, as for a generic acid, which is [H3O+][ OH-]/ [H2O] = 10 -14 /55.5. The pKa is 15.7). The complexed hydroxide is a better nucleophile than bulk water.

7. Classes There are two classes of metal ion_ requiring enzymes that can be distinguished on the basis of their working strength: METALLOENYMES: Contain tightly bound metal ions (Fe2+, Cu2+, Zn2+, Mn2+, Co3+ etc.).   METAL ACTIVATED ENZYMES: Loosely binds metal ions from solution (Na+, K+, Mg2+, Ca2+). Here are some ways through which a metal ion acts as catalyst: By binding to substrate to orient them properly for reaction. By mediating oxidation- reduction reaction through reversible changes in the metal ions oxidation state. By electro-stating stabilizing and shielding negative charges. Often the metal ion act as similar to proton or polarizes water to generate OH . [7]

8. METAL ION OR ELECTROSTATIC CATALYSIS - STABILIZATION OF I TS CHARGE The decarboxylation of dimethyl oxaloacetate can be catalyzed by either Cu2+/Al3+. This happens when the metal ion complexes with the two oxygen atom of reactant, the decarboxylation of the reaction increases by the presences of catalyst hence it formed the carbonyl group. [8]

9. METAL ION CATALYSIS WTH COMPLETE ORIENTATION Carbonic anhydrase is a zinc-containing enzyme that catalyzes the reversible hydration of carbon dioxide. [9]

10. EXAMPLE OF PLATINUIM ION CATALYST: Hydrosilylation reactions, the (commonly) anti- Markovnikov additions of silanes to unsaturated bonds present in compounds such as alkenes and alkynes, offer numerous unique and advantageous properties for the preparation of polymeric materials, such as high yields and stereoselectivity . These reactions require to be catalyzed, for which platinum compounds were used in the initial stages . [10]

11. In spite of the high utility in industry, however, it is known that the platinum catalysts still suffer from a number of drawbacks. For example, platinum- catalysed hydrosilylation of olefins is often accompanied by side reactions, such as dehydrogenative silylation , hydrogenation of olefins, isomerization of olefins, olefin oligomerization and redistribution of hydrosilanes . [11]

12. T he reaction conditions are often harsh, using high temperatures and elevated pressures, with hurdles related to catalyst leeching, reactor corrosion and by-product formation. DISADVANTAGES:

13. REFERENCE https :// www.studocu.com/row/document/jamia-millia-islamia/biochemistry/metal-ion-catalysis/19168471 [1] https:// www.slideshare.net/nourtamim/catalysis-mechanisms [2] https:// onlinelibrary.wiley.com/doi/abs/10.1002/med.21301 [3] https://chem.libretexts.org/Bookshelves/General_Chemistry/Book%3A_Structure_and_Reactivity_in_Organic_Biological_and_Inorganic_Chemistry_%28Schaller%29/V%3A__ Reactivity_in_Organic_Biological_and_Inorganic_Chemistry_3/04%3A_Oxygen_Binding_and_Reduction/4.02%3A_Oxygen_Binding [4] https :// www.studocu.com/row/document/jamia-millia-islamia/biochemistry/metal-ion-catalysis/19168471 [5] https://chem.libretexts.org/Courses/CSU_Chico/CSU_Chico%3A_CHEM_451 __ Biochemistry_I/CHEM_451_Test/09%3A_Catalysis/9.1%3A_A._Methods_of_Catalysis/A2.__ Metal_Ion_or_Electrostatic_Catalysis [6] https:// www.slideshare.net/nourtamim/catalysis-mechanisms [7] https:// www.studocu.com/row/document/jamia-millia-islamia/biochemistry/metal-ion-catalysis/19168471 [8] PPT - Chapter 15 Enzymatic Catalysis PowerPoint Presentation, free download - ID:484310 (slideserve.com ) [9 ] https:// www.researchgate.net/publication/320562283_Fifty_Years_of_Hydrosilylation_in_Polymer_Science_A_Review_of_Current_Trends_of_Low-Cost_Transition-Metal_and_MetalFree_Catalysts_NonThermally_Triggered_Hydrosilylation_Reactions_and_Industrial_Appl [10 ] https:// pubs.rsc.org/en/content/articlehtml/2015/ra/c4ra17281g [11]