SlideShare a Scribd company logo
1 of 21
Download to read offline
Presented by,
D.Keerthana - M.pharm 1st yr,
Dept.of pharmaceuticalchemistry
 Catalysis is the ability of some species to rapidly speed up the rate at
which a chemical reaction proceeds.
 For historical reasons, the discipline is normally split into two sub-
categories; homogeneous (homo = same, geneous = phase) and
heterogeneous (hetero = different).
 Homogeneous catalysis is concerned with catalysts that are in the same
phase as the chemical reactions they are speeding up. These reactions are
normally in the liquid phase and include all of biology's enzymes.
 While the majority of homogeneous catalysis is in the liquid phase there
are gas phase and solid phase homogeneous catalytic reactions.
HOMOGENOUS CATALYSIS:
It refers to catalytic reactions where the catalyst is in the same phase as
the reactants. It applies to the reactions in the gas and liquids phase and even in
solids. In homogeneous catalysis, all the reactants and catalysts are present in a
single fluid phase and usually in the liquid phase.
GENERAL FEATURE:
 Liquid phase reactions dominate the field.
 Industrially less relevant; but complex organic or asymmetric transformations
possible.
 Reaction conditions milder than required for heterogeneous reactions (-78 °C -
~200 °C).
 Investigation of reactions by spectroscopic methods (NMR, MS, IR, UV-Vis)
directly in solution possible.
 Fine-tuning of catalyst properties using different ligands/additives easy
possible.
 Major challenge: Separation of products and catalysts/additives
ADVANTAGES :
In many reactions, homogeneous catalysts are more active and/or
selective compared to heterogeneous catalysts.
In homogeneous catalysis, the catalysts are molecularly dispersed
within the fluid. Hence, pore diffusion limitations are absent. However, bulk
phase mass transfer limitation may occurs.
Catalytic chemistry and mechanism for homogeneous catalysis are
better studied and understood. Therefore, it is easier to control and manipulate
the process parameters.
EXAMPLES OF HOMOGENOUS CATALYSIS
Many of the homogeneous catalysed reactions have
been studied in both gas and liquid phases and some of the common examples in
gas phase are as follows.
In the lead chamber process during the manufacture of
sulphuric acid, the presence of nitric oxide gas helps in catalysing the oxidation
of sulphur dioxide.
During the decomposition of acetaldehyde, the catalysis is carried out by iodine
vapours.
The presence of nitric oxide as catalyst during the combination of carbon
monoxide and oxygen also clarifies the homogeneous catalysis.
 Hydrogenation – meaning, to treat with hydrogen – is a chemical reaction
between molecular hydrogen and another compound or element, usually in the
presence of a catalyst such as nickel, palladium or platinum.
 The process is commonly employed to reduce or saturate organic compounds.
 Hydrogenation reduces double and triple bonds in hydrocarbons.
 The Hydrogenation of alkenes to alkanes at low pressure (1-4 atm) and
moderate temperature (0-100 C) contain nobel metals such as platinum,
palladium or rhodium.
 Example , Hydrogenation of alkenes is an exothermic reaction.
 Mostly Hydrogenation reactions are having high free energies of activation.
MECHANISM:
Steps in the hydrogenation of a C=C double bond at a catalyst
surface, for example Ni or Pt :
(1) The reactants are adsorbed on the catalyst surface
and Hydrogen dissociates.
(2) An H atom bonds to one C atom.
The other C atom is still attached to the surface.
(3) A second C atom bonds to an H atom.
The molecule leaves the surface.
Catalyst used in catalytic hydrogenation reaction are following
 Palladium
 Adam's Catalyst
 Raney Nickel
 Copper Chromite
 Transfer Hydrogenation
 Rhodium
 Ruthenium
 Triethylamine
ADVANTAGES:
1. Relatively high specificity
2. Relatively low reaction temperatures
3. Far more easily studied from chemical & mechanistic aspects
4. Far more active
5. Generally Far more selective for single product.
DISADVANTAGES:
1. More difficult for achieving product/ catalyst separations.
APPLICATIONS:
Applications of Hydrogenation , Requires metal catalyst (Pd, Pt, or Ni).
Used for converting polyunsaturated oils into Margarine
Homogenous catalysis
 Hydroformylation, also known as oxo synthesis or oxo process, is an
industrial process for the production of aldehydes from alkenes.
 This chemical reaction entails the net addition of a formyl group (CHO) and a
hydrogen atom to a carbon-carbon double bond(alkenes)
MECHANISM
 step 1-Mechanism of cobalt- catalyzed hydroformylation. The process begins
with dissociation of CO from cobalt tetracarbonyl hydride to give the 16-
electron species.
 step 2-Subsequent binding of alkene gives an 18e species.
 step 3- The olefin inserts to give the 16e alkyl tricarbonyl.
 step 4-Coordination of another equivalent of CO give alkyl tetracarbonyl .
 step 5-Migratory insertion of CO gives the 16e acyl .
 step 6- oxidative addition of hydrogen gives a dihydrido complex,
 step 7-this dihydrido complex releases aldehyde by reductive elimination.
 step 8- is unproductive and reversible.
Homogenous catalysis
 Hydrocyanation is, the process whereby H+ and –CN ions are added to a
molecular substrate.
 The substrate is an alkene and the product is a nitrile.
 Cyanide is both a good σ–donor and π– acceptor its presence accelerates the
rate of substitution of ligands.
 A key step in hydrocyanation is the oxidative addition of hydrogen cyanide to
low–valent metal complexes.
MECHANISM
 Hydrocyanation is commonly performed on alkenes catalyzed by nickel
complexes of phosphite (P(OR)3) ligands.
 The reaction proceeds via the oxidative addition of HCN to Ni(0) to give a
hydridonickel(II) cyanide complex, abbreviated Ni(H)(CN)L2.
 Subsequent binding of the alkene gives the intermediate Ni(H)(CN)L(alkene),
which then undergoes migratory insertion to give an alkylnickel(II) cyanide
Ni(R)(CN)L2.
 The cycle is completed by the reductive elimination of the nitrile.
APPLICATIONS:
 Hydrocyanation is important due to the versatility of alkyl nitriles (RCN),
which are important intermediates for the syntheses of amides, amines,
carboxylic acids, and esters.
 The most important industrial application is the nickel- catalyzed synthesis of
adiponitrile (NC–(CH2)4–CN) synthesis from 1,3–butadiene (CH2=CH–
CH=CH2).
 Adiponitrile is a precursor to hexamethylenediamine (H2N–(CH2)6–NH2),
which is used for the production of certain kinds of Nylon
 Wilkinson's catalyst, is the common name for chlorido-
tris(triphenylphosphane)rhodium(I), a coordination complex of rhodium with
the formula RhCl(PPh3)3 (Ph = phenyl).
 It is a red-brown colored solid that is soluble in hydrocarbon solvents such as
benzene, and more so in tetrahydrofuran or chlorinated solvents such as
dichloromethane.
 The compound is widely used as a catalyst for hydrogenation of alkenes. It is
named after chemist and Nobel Laureate, Sir Geoffrey Wilkinson, who first
popularized its use.
 Wilkinson's catalyst is usually obtained by treating rhodium(III) chloride
hydrate with an excess of triphenylphosphine in refluxing ethanol.
RhCl3(H2O)3 + 4 PPh3 → RhCl(PPh3)3 + OPPh3 + 2 HCl + 2 H2O
USES:
 It is used in the selective hydrogenation of alkenes and alkynes without
affecting the functional groups like: C=O, CN, NO2, Aryl, CO2R etc.
Wilkinson catalysts Rh+ PH PH PH Cl-
 https://en.m.wikipedia.org/wiki/Homogen eous_catalysis.
 https://chemistry.tutorvista.com/inorganic -chemistry/homogeneous-
catalyst.htmlview=simple
 https://en.m.wikipedia.org/wiki/Hydrofor mylation
 https://en.m.wikipedia.org/wiki/Hydrocya nation
 Green Chemistry and Catalysis”, Roger A. Sheldon, Isabel Arends, Ulf
Hanefold, WILEY-VCH Verlag GmbH & Co. KGaA, Weinhein, Germany; Pg.
no. 106, 223-244, 250, 304, 310, 314.
 “Multistep Continuous-flow Synthesis of (R)- and (S)-Rolipram using
Heterogeneous Catalyst”, Tetsu Tsubogo, Hidekazu Oyamada & Shu
Kobayashin. (DOI: 10.1038/nature14343).
Homogenous catalysis

More Related Content

What's hot

CATALYSIS, TYPES OF CATALYSIS FOR CHEMISTRY STUDENTS
CATALYSIS, TYPES OF CATALYSIS FOR CHEMISTRY STUDENTSCATALYSIS, TYPES OF CATALYSIS FOR CHEMISTRY STUDENTS
CATALYSIS, TYPES OF CATALYSIS FOR CHEMISTRY STUDENTSShikha Popali
 
Homogenous catalysis & Biocatalysis
Homogenous catalysis & BiocatalysisHomogenous catalysis & Biocatalysis
Homogenous catalysis & Biocatalysiskavyakaparthi1
 
C-C Cross Coupling Reactions in Organic chemistry by Anthony crasto
C-C Cross Coupling Reactions in Organic chemistry by Anthony crastoC-C Cross Coupling Reactions in Organic chemistry by Anthony crasto
C-C Cross Coupling Reactions in Organic chemistry by Anthony crastoAnthony Melvin Crasto Ph.D
 
Reduction reactions
Reduction reactionsReduction reactions
Reduction reactionsZaid Najah
 
Retrosynthes analysis and disconnection approach
Retrosynthes analysis and disconnection approach Retrosynthes analysis and disconnection approach
Retrosynthes analysis and disconnection approach ProttayDutta1
 
Heterogeneous catalysis pptx
Heterogeneous catalysis pptxHeterogeneous catalysis pptx
Heterogeneous catalysis pptxZeeshan Nazir
 
Oxidation (Unit Process-1) Pharmaceutical Process Chemistry
Oxidation (Unit Process-1) Pharmaceutical Process Chemistry Oxidation (Unit Process-1) Pharmaceutical Process Chemistry
Oxidation (Unit Process-1) Pharmaceutical Process Chemistry AikanGupta
 
E1 &E2 mechanism, sandmeyer and benzyne mechanism
E1 &E2  mechanism, sandmeyer and benzyne mechanismE1 &E2  mechanism, sandmeyer and benzyne mechanism
E1 &E2 mechanism, sandmeyer and benzyne mechanismlsk1976
 
Hydrogenation reaction
Hydrogenation reactionHydrogenation reaction
Hydrogenation reactionSonali Pimple
 
Katsuki Sharpless Asymmetric Epoxidation and its Synthetic Applications
Katsuki Sharpless Asymmetric Epoxidation and its Synthetic ApplicationsKatsuki Sharpless Asymmetric Epoxidation and its Synthetic Applications
Katsuki Sharpless Asymmetric Epoxidation and its Synthetic ApplicationsKeshav Singh
 
Photoaddition and photo fragmentation reaction
Photoaddition and photo fragmentation reactionPhotoaddition and photo fragmentation reaction
Photoaddition and photo fragmentation reactionAshu Vijay
 

What's hot (20)

CATALYSIS, TYPES OF CATALYSIS FOR CHEMISTRY STUDENTS
CATALYSIS, TYPES OF CATALYSIS FOR CHEMISTRY STUDENTSCATALYSIS, TYPES OF CATALYSIS FOR CHEMISTRY STUDENTS
CATALYSIS, TYPES OF CATALYSIS FOR CHEMISTRY STUDENTS
 
Homogenous catalysis & Biocatalysis
Homogenous catalysis & BiocatalysisHomogenous catalysis & Biocatalysis
Homogenous catalysis & Biocatalysis
 
Protecting groups
Protecting groupsProtecting groups
Protecting groups
 
C-C Cross Coupling Reactions in Organic chemistry by Anthony crasto
C-C Cross Coupling Reactions in Organic chemistry by Anthony crastoC-C Cross Coupling Reactions in Organic chemistry by Anthony crasto
C-C Cross Coupling Reactions in Organic chemistry by Anthony crasto
 
4. Wilkinson's Catalyst
4. Wilkinson's Catalyst4. Wilkinson's Catalyst
4. Wilkinson's Catalyst
 
Reduction Reaction
Reduction Reaction  Reduction Reaction
Reduction Reaction
 
Reduction reactions
Reduction reactionsReduction reactions
Reduction reactions
 
Retrosynthes analysis and disconnection approach
Retrosynthes analysis and disconnection approach Retrosynthes analysis and disconnection approach
Retrosynthes analysis and disconnection approach
 
Asymmetric synthesis
Asymmetric synthesis Asymmetric synthesis
Asymmetric synthesis
 
Heterogeneous catalysis pptx
Heterogeneous catalysis pptxHeterogeneous catalysis pptx
Heterogeneous catalysis pptx
 
Reduction
ReductionReduction
Reduction
 
Oxidation (Unit Process-1) Pharmaceutical Process Chemistry
Oxidation (Unit Process-1) Pharmaceutical Process Chemistry Oxidation (Unit Process-1) Pharmaceutical Process Chemistry
Oxidation (Unit Process-1) Pharmaceutical Process Chemistry
 
Homogenous catalyst
Homogenous catalyst Homogenous catalyst
Homogenous catalyst
 
E1 &E2 mechanism, sandmeyer and benzyne mechanism
E1 &E2  mechanism, sandmeyer and benzyne mechanismE1 &E2  mechanism, sandmeyer and benzyne mechanism
E1 &E2 mechanism, sandmeyer and benzyne mechanism
 
Ugi Reaction
Ugi ReactionUgi Reaction
Ugi Reaction
 
Hydrogenation reaction
Hydrogenation reactionHydrogenation reaction
Hydrogenation reaction
 
Katsuki Sharpless Asymmetric Epoxidation and its Synthetic Applications
Katsuki Sharpless Asymmetric Epoxidation and its Synthetic ApplicationsKatsuki Sharpless Asymmetric Epoxidation and its Synthetic Applications
Katsuki Sharpless Asymmetric Epoxidation and its Synthetic Applications
 
Wilkinson's catalyst
Wilkinson's catalystWilkinson's catalyst
Wilkinson's catalyst
 
Mannich reaction
Mannich reactionMannich reaction
Mannich reaction
 
Photoaddition and photo fragmentation reaction
Photoaddition and photo fragmentation reactionPhotoaddition and photo fragmentation reaction
Photoaddition and photo fragmentation reaction
 

Similar to Homogenous catalysis

Homogeneous catalysis [ MPHARM, MSC, BPHARM, BSC]
Homogeneous catalysis [ MPHARM, MSC, BPHARM, BSC]Homogeneous catalysis [ MPHARM, MSC, BPHARM, BSC]
Homogeneous catalysis [ MPHARM, MSC, BPHARM, BSC]Shikha Popali
 
Thippeswamy B A.pptx
Thippeswamy B A.pptxThippeswamy B A.pptx
Thippeswamy B A.pptxKeerthanN3282
 
Reduction using catalytic hydrogenation
Reduction using catalytic hydrogenationReduction using catalytic hydrogenation
Reduction using catalytic hydrogenationScifySolution
 
Reaction of synthetic importance
Reaction of synthetic importanceReaction of synthetic importance
Reaction of synthetic importanceHemang Bhatt
 
wet air oxidation of hazardous waste
 wet air oxidation of hazardous waste wet air oxidation of hazardous waste
wet air oxidation of hazardous wasteArvind Kumar
 
Chapter 3 Alkenes and Alkynes
Chapter 3 Alkenes and AlkynesChapter 3 Alkenes and Alkynes
Chapter 3 Alkenes and Alkyneselfisusanti
 
Applications of organometallic compounds
Applications of organometallic compoundsApplications of organometallic compounds
Applications of organometallic compoundsPriyanka Jaiswal
 
ppt on hydrogen for class XI th chemistry
ppt on hydrogen for class XI th chemistryppt on hydrogen for class XI th chemistry
ppt on hydrogen for class XI th chemistrylokesh meena
 
ppt on hydrogen for class XI th chemistry
ppt on hydrogen for class XI th chemistryppt on hydrogen for class XI th chemistry
ppt on hydrogen for class XI th chemistrylokesh meena
 
Dehydration Synthesis Of Cyclohexanol
Dehydration Synthesis Of CyclohexanolDehydration Synthesis Of Cyclohexanol
Dehydration Synthesis Of CyclohexanolGina Alfaro
 
wet air oxidation of hazardous waste
 wet air oxidation of hazardous waste wet air oxidation of hazardous waste
wet air oxidation of hazardous wastearvind kumar
 
Presentation1 catalysis
Presentation1 catalysisPresentation1 catalysis
Presentation1 catalysisMuhammad Zahid
 
Named reactions in organic synthesis
Named reactions in organic synthesisNamed reactions in organic synthesis
Named reactions in organic synthesisPRUTHVIRAJ K
 
Aldehydes and Ketones
Aldehydes and KetonesAldehydes and Ketones
Aldehydes and KetonesShivam420J
 

Similar to Homogenous catalysis (20)

Homogeneous catalysis [ MPHARM, MSC, BPHARM, BSC]
Homogeneous catalysis [ MPHARM, MSC, BPHARM, BSC]Homogeneous catalysis [ MPHARM, MSC, BPHARM, BSC]
Homogeneous catalysis [ MPHARM, MSC, BPHARM, BSC]
 
Thippeswamy B A.pptx
Thippeswamy B A.pptxThippeswamy B A.pptx
Thippeswamy B A.pptx
 
Reduction using catalytic hydrogenation
Reduction using catalytic hydrogenationReduction using catalytic hydrogenation
Reduction using catalytic hydrogenation
 
Reaction of synthetic importance
Reaction of synthetic importanceReaction of synthetic importance
Reaction of synthetic importance
 
Catalysis
CatalysisCatalysis
Catalysis
 
wet air oxidation of hazardous waste
 wet air oxidation of hazardous waste wet air oxidation of hazardous waste
wet air oxidation of hazardous waste
 
Chapter 3 Alkenes and Alkynes
Chapter 3 Alkenes and AlkynesChapter 3 Alkenes and Alkynes
Chapter 3 Alkenes and Alkynes
 
Applications of organometallic compounds
Applications of organometallic compoundsApplications of organometallic compounds
Applications of organometallic compounds
 
ppt on hydrogen for class XI th chemistry
ppt on hydrogen for class XI th chemistryppt on hydrogen for class XI th chemistry
ppt on hydrogen for class XI th chemistry
 
ppt on hydrogen for class XI th chemistry
ppt on hydrogen for class XI th chemistryppt on hydrogen for class XI th chemistry
ppt on hydrogen for class XI th chemistry
 
19 redox
19 redox19 redox
19 redox
 
Dehydration Synthesis Of Cyclohexanol
Dehydration Synthesis Of CyclohexanolDehydration Synthesis Of Cyclohexanol
Dehydration Synthesis Of Cyclohexanol
 
wet air oxidation of hazardous waste
 wet air oxidation of hazardous waste wet air oxidation of hazardous waste
wet air oxidation of hazardous waste
 
Catalysis
CatalysisCatalysis
Catalysis
 
REDUCTION.pptx
REDUCTION.pptxREDUCTION.pptx
REDUCTION.pptx
 
Presentation1 catalysis
Presentation1 catalysisPresentation1 catalysis
Presentation1 catalysis
 
ch 9 hydrogen.pdf
ch 9 hydrogen.pdfch 9 hydrogen.pdf
ch 9 hydrogen.pdf
 
Named reactions in organic synthesis
Named reactions in organic synthesisNamed reactions in organic synthesis
Named reactions in organic synthesis
 
Hydrogenation
HydrogenationHydrogenation
Hydrogenation
 
Aldehydes and Ketones
Aldehydes and KetonesAldehydes and Ketones
Aldehydes and Ketones
 

Recently uploaded

THE HISTOLOGY OF THE CARDIOVASCULAR SYSTEM 2024.pptx
THE HISTOLOGY OF THE CARDIOVASCULAR SYSTEM 2024.pptxTHE HISTOLOGY OF THE CARDIOVASCULAR SYSTEM 2024.pptx
THE HISTOLOGY OF THE CARDIOVASCULAR SYSTEM 2024.pptxAkinrotimiOluwadunsi
 
IB Biology New syllabus B3.2 Transport.pptx
IB Biology New syllabus B3.2 Transport.pptxIB Biology New syllabus B3.2 Transport.pptx
IB Biology New syllabus B3.2 Transport.pptxUalikhanKalkhojayev1
 
Pests of cumbu_Identification, Binomics, Integrated ManagementDr.UPR.pdf
Pests of cumbu_Identification, Binomics, Integrated ManagementDr.UPR.pdfPests of cumbu_Identification, Binomics, Integrated ManagementDr.UPR.pdf
Pests of cumbu_Identification, Binomics, Integrated ManagementDr.UPR.pdfPirithiRaju
 
Physics Serway Jewett 6th edition for Scientists and Engineers
Physics Serway Jewett 6th edition for Scientists and EngineersPhysics Serway Jewett 6th edition for Scientists and Engineers
Physics Serway Jewett 6th edition for Scientists and EngineersAndreaLucarelli
 
Applied Biochemistry feedback_M Ahwad 2023.docx
Applied Biochemistry feedback_M Ahwad 2023.docxApplied Biochemistry feedback_M Ahwad 2023.docx
Applied Biochemistry feedback_M Ahwad 2023.docxmarwaahmad357
 
PSP3 employability assessment form .docx
PSP3 employability assessment form .docxPSP3 employability assessment form .docx
PSP3 employability assessment form .docxmarwaahmad357
 
M.Pharm - Question Bank - Drug Delivery Systems
M.Pharm - Question Bank - Drug Delivery SystemsM.Pharm - Question Bank - Drug Delivery Systems
M.Pharm - Question Bank - Drug Delivery SystemsSumathi Arumugam
 
Human brain.. It's parts and function.
Human brain.. It's parts and function. Human brain.. It's parts and function.
Human brain.. It's parts and function. MUKTA MANJARI SAHOO
 
3.2 Pests of Sorghum_Identification, Symptoms and nature of damage, Binomics,...
3.2 Pests of Sorghum_Identification, Symptoms and nature of damage, Binomics,...3.2 Pests of Sorghum_Identification, Symptoms and nature of damage, Binomics,...
3.2 Pests of Sorghum_Identification, Symptoms and nature of damage, Binomics,...PirithiRaju
 
Principles & Formulation of Hair Care Products
Principles & Formulation of Hair Care  ProductsPrinciples & Formulation of Hair Care  Products
Principles & Formulation of Hair Care Productspurwaborkar@gmail.com
 
soft skills question paper set for bba ca
soft skills question paper set for bba casoft skills question paper set for bba ca
soft skills question paper set for bba caohsadfeeling
 
Pests of wheat_Identification, Bionomics, Damage symptoms, IPM_Dr.UPR.pdf
Pests of wheat_Identification, Bionomics, Damage symptoms, IPM_Dr.UPR.pdfPests of wheat_Identification, Bionomics, Damage symptoms, IPM_Dr.UPR.pdf
Pests of wheat_Identification, Bionomics, Damage symptoms, IPM_Dr.UPR.pdfPirithiRaju
 
Main Exam Applied biochemistry final year
Main Exam Applied biochemistry final yearMain Exam Applied biochemistry final year
Main Exam Applied biochemistry final yearmarwaahmad357
 
Role of Herbs in Cosmetics in Cosmetic Science.
Role of Herbs in Cosmetics in Cosmetic Science.Role of Herbs in Cosmetics in Cosmetic Science.
Role of Herbs in Cosmetics in Cosmetic Science.ShwetaHattimare
 
RCPE terms and cycles scenarios as of March 2024
RCPE terms and cycles scenarios as of March 2024RCPE terms and cycles scenarios as of March 2024
RCPE terms and cycles scenarios as of March 2024suelcarter1
 
Digitized Continuous Magnetic Recordings for the August/September 1859 Storms...
Digitized Continuous Magnetic Recordings for the August/September 1859 Storms...Digitized Continuous Magnetic Recordings for the August/September 1859 Storms...
Digitized Continuous Magnetic Recordings for the August/September 1859 Storms...Sérgio Sacani
 
CW marking grid Analytical BS - M Ahmad.docx
CW  marking grid Analytical BS - M Ahmad.docxCW  marking grid Analytical BS - M Ahmad.docx
CW marking grid Analytical BS - M Ahmad.docxmarwaahmad357
 
MARKER ASSISTED SELECTION IN CROP IMPROVEMENT
MARKER ASSISTED SELECTION IN CROP IMPROVEMENTMARKER ASSISTED SELECTION IN CROP IMPROVEMENT
MARKER ASSISTED SELECTION IN CROP IMPROVEMENTjipexe1248
 
Pests of Redgram_Identification, Binomics_Dr.UPR
Pests of Redgram_Identification, Binomics_Dr.UPRPests of Redgram_Identification, Binomics_Dr.UPR
Pests of Redgram_Identification, Binomics_Dr.UPRPirithiRaju
 

Recently uploaded (20)

THE HISTOLOGY OF THE CARDIOVASCULAR SYSTEM 2024.pptx
THE HISTOLOGY OF THE CARDIOVASCULAR SYSTEM 2024.pptxTHE HISTOLOGY OF THE CARDIOVASCULAR SYSTEM 2024.pptx
THE HISTOLOGY OF THE CARDIOVASCULAR SYSTEM 2024.pptx
 
IB Biology New syllabus B3.2 Transport.pptx
IB Biology New syllabus B3.2 Transport.pptxIB Biology New syllabus B3.2 Transport.pptx
IB Biology New syllabus B3.2 Transport.pptx
 
Pests of cumbu_Identification, Binomics, Integrated ManagementDr.UPR.pdf
Pests of cumbu_Identification, Binomics, Integrated ManagementDr.UPR.pdfPests of cumbu_Identification, Binomics, Integrated ManagementDr.UPR.pdf
Pests of cumbu_Identification, Binomics, Integrated ManagementDr.UPR.pdf
 
Physics Serway Jewett 6th edition for Scientists and Engineers
Physics Serway Jewett 6th edition for Scientists and EngineersPhysics Serway Jewett 6th edition for Scientists and Engineers
Physics Serway Jewett 6th edition for Scientists and Engineers
 
Applied Biochemistry feedback_M Ahwad 2023.docx
Applied Biochemistry feedback_M Ahwad 2023.docxApplied Biochemistry feedback_M Ahwad 2023.docx
Applied Biochemistry feedback_M Ahwad 2023.docx
 
PSP3 employability assessment form .docx
PSP3 employability assessment form .docxPSP3 employability assessment form .docx
PSP3 employability assessment form .docx
 
M.Pharm - Question Bank - Drug Delivery Systems
M.Pharm - Question Bank - Drug Delivery SystemsM.Pharm - Question Bank - Drug Delivery Systems
M.Pharm - Question Bank - Drug Delivery Systems
 
Human brain.. It's parts and function.
Human brain.. It's parts and function. Human brain.. It's parts and function.
Human brain.. It's parts and function.
 
3.2 Pests of Sorghum_Identification, Symptoms and nature of damage, Binomics,...
3.2 Pests of Sorghum_Identification, Symptoms and nature of damage, Binomics,...3.2 Pests of Sorghum_Identification, Symptoms and nature of damage, Binomics,...
3.2 Pests of Sorghum_Identification, Symptoms and nature of damage, Binomics,...
 
Principles & Formulation of Hair Care Products
Principles & Formulation of Hair Care  ProductsPrinciples & Formulation of Hair Care  Products
Principles & Formulation of Hair Care Products
 
soft skills question paper set for bba ca
soft skills question paper set for bba casoft skills question paper set for bba ca
soft skills question paper set for bba ca
 
Pests of wheat_Identification, Bionomics, Damage symptoms, IPM_Dr.UPR.pdf
Pests of wheat_Identification, Bionomics, Damage symptoms, IPM_Dr.UPR.pdfPests of wheat_Identification, Bionomics, Damage symptoms, IPM_Dr.UPR.pdf
Pests of wheat_Identification, Bionomics, Damage symptoms, IPM_Dr.UPR.pdf
 
Cheminformatics tools supporting dissemination of data associated with US EPA...
Cheminformatics tools supporting dissemination of data associated with US EPA...Cheminformatics tools supporting dissemination of data associated with US EPA...
Cheminformatics tools supporting dissemination of data associated with US EPA...
 
Main Exam Applied biochemistry final year
Main Exam Applied biochemistry final yearMain Exam Applied biochemistry final year
Main Exam Applied biochemistry final year
 
Role of Herbs in Cosmetics in Cosmetic Science.
Role of Herbs in Cosmetics in Cosmetic Science.Role of Herbs in Cosmetics in Cosmetic Science.
Role of Herbs in Cosmetics in Cosmetic Science.
 
RCPE terms and cycles scenarios as of March 2024
RCPE terms and cycles scenarios as of March 2024RCPE terms and cycles scenarios as of March 2024
RCPE terms and cycles scenarios as of March 2024
 
Digitized Continuous Magnetic Recordings for the August/September 1859 Storms...
Digitized Continuous Magnetic Recordings for the August/September 1859 Storms...Digitized Continuous Magnetic Recordings for the August/September 1859 Storms...
Digitized Continuous Magnetic Recordings for the August/September 1859 Storms...
 
CW marking grid Analytical BS - M Ahmad.docx
CW  marking grid Analytical BS - M Ahmad.docxCW  marking grid Analytical BS - M Ahmad.docx
CW marking grid Analytical BS - M Ahmad.docx
 
MARKER ASSISTED SELECTION IN CROP IMPROVEMENT
MARKER ASSISTED SELECTION IN CROP IMPROVEMENTMARKER ASSISTED SELECTION IN CROP IMPROVEMENT
MARKER ASSISTED SELECTION IN CROP IMPROVEMENT
 
Pests of Redgram_Identification, Binomics_Dr.UPR
Pests of Redgram_Identification, Binomics_Dr.UPRPests of Redgram_Identification, Binomics_Dr.UPR
Pests of Redgram_Identification, Binomics_Dr.UPR
 

Homogenous catalysis

  • 1. Presented by, D.Keerthana - M.pharm 1st yr, Dept.of pharmaceuticalchemistry
  • 2.  Catalysis is the ability of some species to rapidly speed up the rate at which a chemical reaction proceeds.  For historical reasons, the discipline is normally split into two sub- categories; homogeneous (homo = same, geneous = phase) and heterogeneous (hetero = different).  Homogeneous catalysis is concerned with catalysts that are in the same phase as the chemical reactions they are speeding up. These reactions are normally in the liquid phase and include all of biology's enzymes.  While the majority of homogeneous catalysis is in the liquid phase there are gas phase and solid phase homogeneous catalytic reactions.
  • 3. HOMOGENOUS CATALYSIS: It refers to catalytic reactions where the catalyst is in the same phase as the reactants. It applies to the reactions in the gas and liquids phase and even in solids. In homogeneous catalysis, all the reactants and catalysts are present in a single fluid phase and usually in the liquid phase. GENERAL FEATURE:  Liquid phase reactions dominate the field.  Industrially less relevant; but complex organic or asymmetric transformations possible.
  • 4.  Reaction conditions milder than required for heterogeneous reactions (-78 °C - ~200 °C).  Investigation of reactions by spectroscopic methods (NMR, MS, IR, UV-Vis) directly in solution possible.  Fine-tuning of catalyst properties using different ligands/additives easy possible.  Major challenge: Separation of products and catalysts/additives ADVANTAGES : In many reactions, homogeneous catalysts are more active and/or selective compared to heterogeneous catalysts. In homogeneous catalysis, the catalysts are molecularly dispersed within the fluid. Hence, pore diffusion limitations are absent. However, bulk phase mass transfer limitation may occurs. Catalytic chemistry and mechanism for homogeneous catalysis are better studied and understood. Therefore, it is easier to control and manipulate the process parameters.
  • 5. EXAMPLES OF HOMOGENOUS CATALYSIS Many of the homogeneous catalysed reactions have been studied in both gas and liquid phases and some of the common examples in gas phase are as follows. In the lead chamber process during the manufacture of sulphuric acid, the presence of nitric oxide gas helps in catalysing the oxidation of sulphur dioxide. During the decomposition of acetaldehyde, the catalysis is carried out by iodine vapours. The presence of nitric oxide as catalyst during the combination of carbon monoxide and oxygen also clarifies the homogeneous catalysis.
  • 6.  Hydrogenation – meaning, to treat with hydrogen – is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum.  The process is commonly employed to reduce or saturate organic compounds.  Hydrogenation reduces double and triple bonds in hydrocarbons.  The Hydrogenation of alkenes to alkanes at low pressure (1-4 atm) and moderate temperature (0-100 C) contain nobel metals such as platinum, palladium or rhodium.
  • 7.  Example , Hydrogenation of alkenes is an exothermic reaction.  Mostly Hydrogenation reactions are having high free energies of activation.
  • 8. MECHANISM: Steps in the hydrogenation of a C=C double bond at a catalyst surface, for example Ni or Pt : (1) The reactants are adsorbed on the catalyst surface and Hydrogen dissociates. (2) An H atom bonds to one C atom. The other C atom is still attached to the surface. (3) A second C atom bonds to an H atom. The molecule leaves the surface.
  • 9. Catalyst used in catalytic hydrogenation reaction are following  Palladium  Adam's Catalyst  Raney Nickel  Copper Chromite  Transfer Hydrogenation  Rhodium  Ruthenium  Triethylamine
  • 10. ADVANTAGES: 1. Relatively high specificity 2. Relatively low reaction temperatures 3. Far more easily studied from chemical & mechanistic aspects 4. Far more active 5. Generally Far more selective for single product. DISADVANTAGES: 1. More difficult for achieving product/ catalyst separations. APPLICATIONS: Applications of Hydrogenation , Requires metal catalyst (Pd, Pt, or Ni). Used for converting polyunsaturated oils into Margarine
  • 12.  Hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes from alkenes.  This chemical reaction entails the net addition of a formyl group (CHO) and a hydrogen atom to a carbon-carbon double bond(alkenes)
  • 13. MECHANISM  step 1-Mechanism of cobalt- catalyzed hydroformylation. The process begins with dissociation of CO from cobalt tetracarbonyl hydride to give the 16- electron species.  step 2-Subsequent binding of alkene gives an 18e species.  step 3- The olefin inserts to give the 16e alkyl tricarbonyl.  step 4-Coordination of another equivalent of CO give alkyl tetracarbonyl .  step 5-Migratory insertion of CO gives the 16e acyl .  step 6- oxidative addition of hydrogen gives a dihydrido complex,  step 7-this dihydrido complex releases aldehyde by reductive elimination.  step 8- is unproductive and reversible.
  • 15.  Hydrocyanation is, the process whereby H+ and –CN ions are added to a molecular substrate.  The substrate is an alkene and the product is a nitrile.  Cyanide is both a good σ–donor and π– acceptor its presence accelerates the rate of substitution of ligands.  A key step in hydrocyanation is the oxidative addition of hydrogen cyanide to low–valent metal complexes.
  • 16. MECHANISM  Hydrocyanation is commonly performed on alkenes catalyzed by nickel complexes of phosphite (P(OR)3) ligands.  The reaction proceeds via the oxidative addition of HCN to Ni(0) to give a hydridonickel(II) cyanide complex, abbreviated Ni(H)(CN)L2.  Subsequent binding of the alkene gives the intermediate Ni(H)(CN)L(alkene), which then undergoes migratory insertion to give an alkylnickel(II) cyanide Ni(R)(CN)L2.  The cycle is completed by the reductive elimination of the nitrile.
  • 17. APPLICATIONS:  Hydrocyanation is important due to the versatility of alkyl nitriles (RCN), which are important intermediates for the syntheses of amides, amines, carboxylic acids, and esters.  The most important industrial application is the nickel- catalyzed synthesis of adiponitrile (NC–(CH2)4–CN) synthesis from 1,3–butadiene (CH2=CH– CH=CH2).  Adiponitrile is a precursor to hexamethylenediamine (H2N–(CH2)6–NH2), which is used for the production of certain kinds of Nylon
  • 18.  Wilkinson's catalyst, is the common name for chlorido- tris(triphenylphosphane)rhodium(I), a coordination complex of rhodium with the formula RhCl(PPh3)3 (Ph = phenyl).  It is a red-brown colored solid that is soluble in hydrocarbon solvents such as benzene, and more so in tetrahydrofuran or chlorinated solvents such as dichloromethane.  The compound is widely used as a catalyst for hydrogenation of alkenes. It is named after chemist and Nobel Laureate, Sir Geoffrey Wilkinson, who first popularized its use.
  • 19.  Wilkinson's catalyst is usually obtained by treating rhodium(III) chloride hydrate with an excess of triphenylphosphine in refluxing ethanol. RhCl3(H2O)3 + 4 PPh3 → RhCl(PPh3)3 + OPPh3 + 2 HCl + 2 H2O USES:  It is used in the selective hydrogenation of alkenes and alkynes without affecting the functional groups like: C=O, CN, NO2, Aryl, CO2R etc. Wilkinson catalysts Rh+ PH PH PH Cl-
  • 20.  https://en.m.wikipedia.org/wiki/Homogen eous_catalysis.  https://chemistry.tutorvista.com/inorganic -chemistry/homogeneous- catalyst.htmlview=simple  https://en.m.wikipedia.org/wiki/Hydrofor mylation  https://en.m.wikipedia.org/wiki/Hydrocya nation  Green Chemistry and Catalysis”, Roger A. Sheldon, Isabel Arends, Ulf Hanefold, WILEY-VCH Verlag GmbH & Co. KGaA, Weinhein, Germany; Pg. no. 106, 223-244, 250, 304, 310, 314.  “Multistep Continuous-flow Synthesis of (R)- and (S)-Rolipram using Heterogeneous Catalyst”, Tetsu Tsubogo, Hidekazu Oyamada & Shu Kobayashin. (DOI: 10.1038/nature14343).