logging in or signing up IR Seminar--Surajit Saha sorcar Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 929 Category: Science & Tech.. License: All Rights Reserved Like it (4) Dislike it (1) Added: October 12, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... By: kumaraswamy.gandla (17 month(s) ago) SIR I NEED IR SPECTROSCOPIC ppt urgently Saving..... Post Reply Close Saving..... Edit Comment Close By: abumaryam (18 month(s) ago) sir can i have a copy of yr pp im mpharm 1st year mmucp bangalore rmgm 571511 thank u Saving..... Post Reply Close Saving..... Edit Comment Close By: avanigupta (18 month(s) ago) nice discription can i download ths ppt Saving..... Post Reply Close Saving..... Edit Comment Close By: sharma.sindhu (19 month(s) ago) hi sir! i found ur ppt really informative and understandable; could u plz forward me one copy of dis on ma email id-sharma.sindhu20@gmail.com waiting for ur positive response..... Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Slide 1: WELCOME YOU ALL Slide 2: THEORY & PRINCIPLE OF IR SPECTRA By SURAJIT SAHA M.PHARM 1ST SEMESTER DEPT. OF PHARMACEUTICS CONTENTS :--- : CONTENTS :--- Introduction IR Region Units used Principle IR Spectrum Theory of Molecular Vibration Vibrational Frequency Factor affecting vibrational frequency Reference INTRODUCTION : INTRODUCTION IR spectroscopy is the subset of spectroscopy that deals with the infra-red region of the electromagnetic spectrum. IR spectroscopy is one of the most widely used tools for detection of functional groups in pure compounds and mixtures, and for compound comparison. The spectrum is obtained in minutes using a few mg of the compound, which too can be retrieved. IR REGION : IR REGION (µ) (cm-1) UNITS USED : UNITS USED Wavelength = Measured in microns (µ) Wave Number =Measured in reciprocal cm(cm-1 ) Relationship between units :--- Wave Number in cm-1 = 1000 Wavelength in µ PRINCIPLe : PRINCIPLe Atoms are connected by bonds. Bonds are analogous to springs & not rigid. Continuous motion of the molecule maintain some vibration with some frequency is called “Natural frequency of vibration.” APPLIED INFRARED FREQUENCY = NATURAL FREQUENCY OF VIBRATION Slide 8: Absorbed energy brings about predominant changes in the vibrational energy which depends upon:-- Masses of the atom present in a molecule. Strength of the bonds. The arrangement of atoms within the molecules. NB:-- It has been found that no two compounds except the enantiomers can have similar Infra-red spectra. IR SPECTRUM : IR SPECTRUM IR spectrum is a graph of % Transmittance versus either increasing wavelength or decreasing frequency. Each dip in the spectrum called a band or peak, represents absorption of IR radiation at that frequency by the sample. Slide 10: Plot IR energy vs. % transmittance (%T) – Energy scale in wave numbers, wn (cm-1) – %T scale Compares intensity of IR striking sample (Iin) with intensity of IR leaving sample (Iout) 100%T - no light absorbed by sample 0% T - all light absorbed by sample incident IR (Iin) transmitted IR (Iout) %T = 100 x (Iout / Iin) SAMPLE Slide 11: Record Wave number location of IR “band” (position of max%T) Intensity of IR “band” s = strong (low %T), m = medium, w = weak (high %T) s m m w 100% T 0% T THEORY OF MOLECULAR VIBRATION : THEORY OF MOLECULAR VIBRATION Slide 14: STRETCHING Symmetrical Asymmetrical Slide 15: Bending In plane bending Scissoring Rocking Out of plane bending Wagging Twisting VIBRATIONAL FREQUENCY : VIBRATIONAL FREQUENCY The value of stretching vibrational frequency of a bond can be calculated by HOOKE’s Law……….. v = frequency m1 & m2 = masses of the atoms concerned in grams k = force constant or strength of the bond FACTORS INFLUENCING VIBRATIONAL FREQUENCIES : FACTORS INFLUENCING VIBRATIONAL FREQUENCIES Vibrational coupling Hydrogen bonding Electronic effects Bond angles Vibrational coupling:---- : Vibrational coupling:---- Fig::Stretching vibrations in methylene group Fig::Types of stretching vibrations methyl group Asymmetric Symmetric Symmetric Asymmetric COUPLING IS USEFUL FOR DETECTION OF:-- : COUPLING IS USEFUL FOR DETECTION OF:-- Carboxylic acid anhydrides (C=O str ) Primary amines (N-H def &C-H str) & primary amides (C=O str & N-H def ) Nitro compounds, sulfones, carboxylate anions Secondary amines HYDROGEN BONDING:---- : HYDROGEN BONDING:---- H-bonding present in O-H & N-H compounds give rise to a no. of effects in the IR spectra. Electronegativity O-H > N-H ELECTRONIC EFFECT:---- : ELECTRONIC EFFECT:---- Formaldehyde (H-CO-H)---1750cm-1 Acetaldehyde (CH3-CO-H)---1745cm-1 Acetone (CH3-CO-CH3)---1715cm-1 Note-Aldehyde absorb higher wave no. than ketone Acetone (CH3-CO-CH3)---1715cm-1 Chloroacetone (CH3-CO-CH2-Cl)---1725cm-1 Dichloroacetone (CH3-CO-CH-Cl2)---1740cm-1 Tetrachloroacetone (Cl2-CH-CO-CH-Cl2)---1750cm-1 BOND ANGLE:---- : BOND ANGLE:---- BOND ANGLE < 1200 Cyclobutanone Acetone (1788cm-1) (1715cm-1) CONCLUSION : CONCLUSION Thus it has been concluded that this technique of identification of compounds , in spite of having a complex phenomenon & characterization but it follows a simple as well as sophisticated & well defined system or technology ,along with it has contributed a lot in the field of pharmaceutical technology for most accurate & convenient results for which it has been intended. REFERENCES : REFERENCES SharmaY.R., Elementary Organic Spectroscopy Forth edition,S.Chand & Company Ltd.pp-65-81 Gurdeep R. Chatwal & Sham K. Anand, Instrumental Methods of Chemical Analysis,Fifth edition,Himalaya Publishing House,pp-2.31-2.60. Dr.Sankar.S.Ravi,Textbook of Pharmaceutical Analysis,Third edition ,Rx Publications,pp-5.1-5.4 Braun D. Robert ,Introduction To Instrumental Analysis,Second Revised Edition,Pharma Book Syndicate,pp-346-413 http://www.shu.ac.uk/schools/sci/chem/tutorials/molspec/irspec2.htm www.bnl.gov/nsls2/workshops/docs/userworkshop/bos/.../Miller.IR.pdf http://www.cem.msu.edu/~reusch/VirtualText/Spectrpy/InfraRed/irspec1.htm Slide 25: THANK YOU You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
IR Seminar--Surajit Saha sorcar Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 929 Category: Science & Tech.. License: All Rights Reserved Like it (4) Dislike it (1) Added: October 12, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... By: kumaraswamy.gandla (17 month(s) ago) SIR I NEED IR SPECTROSCOPIC ppt urgently Saving..... Post Reply Close Saving..... Edit Comment Close By: abumaryam (18 month(s) ago) sir can i have a copy of yr pp im mpharm 1st year mmucp bangalore rmgm 571511 thank u Saving..... Post Reply Close Saving..... Edit Comment Close By: avanigupta (18 month(s) ago) nice discription can i download ths ppt Saving..... Post Reply Close Saving..... Edit Comment Close By: sharma.sindhu (19 month(s) ago) hi sir! i found ur ppt really informative and understandable; could u plz forward me one copy of dis on ma email id-sharma.sindhu20@gmail.com waiting for ur positive response..... Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Slide 1: WELCOME YOU ALL Slide 2: THEORY & PRINCIPLE OF IR SPECTRA By SURAJIT SAHA M.PHARM 1ST SEMESTER DEPT. OF PHARMACEUTICS CONTENTS :--- : CONTENTS :--- Introduction IR Region Units used Principle IR Spectrum Theory of Molecular Vibration Vibrational Frequency Factor affecting vibrational frequency Reference INTRODUCTION : INTRODUCTION IR spectroscopy is the subset of spectroscopy that deals with the infra-red region of the electromagnetic spectrum. IR spectroscopy is one of the most widely used tools for detection of functional groups in pure compounds and mixtures, and for compound comparison. The spectrum is obtained in minutes using a few mg of the compound, which too can be retrieved. IR REGION : IR REGION (µ) (cm-1) UNITS USED : UNITS USED Wavelength = Measured in microns (µ) Wave Number =Measured in reciprocal cm(cm-1 ) Relationship between units :--- Wave Number in cm-1 = 1000 Wavelength in µ PRINCIPLe : PRINCIPLe Atoms are connected by bonds. Bonds are analogous to springs & not rigid. Continuous motion of the molecule maintain some vibration with some frequency is called “Natural frequency of vibration.” APPLIED INFRARED FREQUENCY = NATURAL FREQUENCY OF VIBRATION Slide 8: Absorbed energy brings about predominant changes in the vibrational energy which depends upon:-- Masses of the atom present in a molecule. Strength of the bonds. The arrangement of atoms within the molecules. NB:-- It has been found that no two compounds except the enantiomers can have similar Infra-red spectra. IR SPECTRUM : IR SPECTRUM IR spectrum is a graph of % Transmittance versus either increasing wavelength or decreasing frequency. Each dip in the spectrum called a band or peak, represents absorption of IR radiation at that frequency by the sample. Slide 10: Plot IR energy vs. % transmittance (%T) – Energy scale in wave numbers, wn (cm-1) – %T scale Compares intensity of IR striking sample (Iin) with intensity of IR leaving sample (Iout) 100%T - no light absorbed by sample 0% T - all light absorbed by sample incident IR (Iin) transmitted IR (Iout) %T = 100 x (Iout / Iin) SAMPLE Slide 11: Record Wave number location of IR “band” (position of max%T) Intensity of IR “band” s = strong (low %T), m = medium, w = weak (high %T) s m m w 100% T 0% T THEORY OF MOLECULAR VIBRATION : THEORY OF MOLECULAR VIBRATION Slide 14: STRETCHING Symmetrical Asymmetrical Slide 15: Bending In plane bending Scissoring Rocking Out of plane bending Wagging Twisting VIBRATIONAL FREQUENCY : VIBRATIONAL FREQUENCY The value of stretching vibrational frequency of a bond can be calculated by HOOKE’s Law……….. v = frequency m1 & m2 = masses of the atoms concerned in grams k = force constant or strength of the bond FACTORS INFLUENCING VIBRATIONAL FREQUENCIES : FACTORS INFLUENCING VIBRATIONAL FREQUENCIES Vibrational coupling Hydrogen bonding Electronic effects Bond angles Vibrational coupling:---- : Vibrational coupling:---- Fig::Stretching vibrations in methylene group Fig::Types of stretching vibrations methyl group Asymmetric Symmetric Symmetric Asymmetric COUPLING IS USEFUL FOR DETECTION OF:-- : COUPLING IS USEFUL FOR DETECTION OF:-- Carboxylic acid anhydrides (C=O str ) Primary amines (N-H def &C-H str) & primary amides (C=O str & N-H def ) Nitro compounds, sulfones, carboxylate anions Secondary amines HYDROGEN BONDING:---- : HYDROGEN BONDING:---- H-bonding present in O-H & N-H compounds give rise to a no. of effects in the IR spectra. Electronegativity O-H > N-H ELECTRONIC EFFECT:---- : ELECTRONIC EFFECT:---- Formaldehyde (H-CO-H)---1750cm-1 Acetaldehyde (CH3-CO-H)---1745cm-1 Acetone (CH3-CO-CH3)---1715cm-1 Note-Aldehyde absorb higher wave no. than ketone Acetone (CH3-CO-CH3)---1715cm-1 Chloroacetone (CH3-CO-CH2-Cl)---1725cm-1 Dichloroacetone (CH3-CO-CH-Cl2)---1740cm-1 Tetrachloroacetone (Cl2-CH-CO-CH-Cl2)---1750cm-1 BOND ANGLE:---- : BOND ANGLE:---- BOND ANGLE < 1200 Cyclobutanone Acetone (1788cm-1) (1715cm-1) CONCLUSION : CONCLUSION Thus it has been concluded that this technique of identification of compounds , in spite of having a complex phenomenon & characterization but it follows a simple as well as sophisticated & well defined system or technology ,along with it has contributed a lot in the field of pharmaceutical technology for most accurate & convenient results for which it has been intended. REFERENCES : REFERENCES SharmaY.R., Elementary Organic Spectroscopy Forth edition,S.Chand & Company Ltd.pp-65-81 Gurdeep R. Chatwal & Sham K. Anand, Instrumental Methods of Chemical Analysis,Fifth edition,Himalaya Publishing House,pp-2.31-2.60. Dr.Sankar.S.Ravi,Textbook of Pharmaceutical Analysis,Third edition ,Rx Publications,pp-5.1-5.4 Braun D. Robert ,Introduction To Instrumental Analysis,Second Revised Edition,Pharma Book Syndicate,pp-346-413 http://www.shu.ac.uk/schools/sci/chem/tutorials/molspec/irspec2.htm www.bnl.gov/nsls2/workshops/docs/userworkshop/bos/.../Miller.IR.pdf http://www.cem.msu.edu/~reusch/VirtualText/Spectrpy/InfraRed/irspec1.htm Slide 25: THANK YOU