Infrared Spectroscopy 紅 外 線 光 譜 儀

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Infrared Spectroscopy 紅 外 線 光 譜 儀"

Transcription

1 Infrared Spectroscopy 紅 外 線 光 譜 儀

2 Introduction Spectroscopy is an analytical technique which helps determine structure. It destroys little or no sample (nondestructive method). The amount of light absorbed by the sample is measured as wavelength is varied. Chapter 12 2

3 Types of Spectroscopy Infrared (IR) spectroscopy measures the bond vibration frequencies in a molecule and is used to determine the functional group. Mass spectrometry (MS) fragments the molecule and measures the masses. Nuclear magnetic resonance (NMR) spectroscopy detects signals from hydrogen atoms and can be used to distinguish isomers. Ultraviolet (UV) spectroscopy uses electron transitions to determine bonding patterns. => Chapter 12 3

4 Electromagnetic Spectrum Examples: X rays, microwaves, radio waves, visible light, IR, and UV. Electromagnetic radiation has the characteristics of both waves and particles The wave nature of electromagnetic radiation is described by wavelength (l) or frequency (n) The relationship between wavelength (or frequency) and energy (E) is well defined Wavelength and frequency are inversely proportional (n= c/l) The higher the frequency, the greater the energy of the wave The shorter the wavelength, the greater the energy of the wave Chapter 12 4

5 The Spectrum and Molecular Effects => Chapter 12 5 =>

6 The IR Region Just below red in the visible region. Wavelengths usually mm. More common units are wavenumbers, or cm -1, the reciprocal of the wavelength in centimeters. Wavenumbers are proportional to frequency and energy. Chapter 12 => 6

7 Molecular Vibrations Covalent bonds vibrate at only certain allowable frequencies. => Chapter 12 7

8 Stretching Frequencies Frequency decreases with increasing atomic weight. Frequency increases with increasing bond energy. => Chapter 12 8

9 Chapter 12 9

10 Vibrational Modes Nonlinear molecule with n atoms usually has 3n - 6 fundamental vibrational modes. Chapter 12 10

11 Chapter 12 11

12 Fingerprint of Molecule No two molecules will give exactly the same IR spectrum (except enantiomers). Simple stretching: cm -1 has the most common vibrations, and we can use it to get information about specific functional groups in the molecule. Complex vibrations (bending): cm -1, called the fingerprint region and has the most complex vibrations. Chapter 12 12

13 IR-Active and Inactive A polar bond is usually IR-active. A nonpolar bond in a symmetrical molecule will absorb weakly or not at all. Chapter 12 13

14 Chapter 12 14

15 An Infrared Spectrometer Chapter =>

16 FT IR Spectrometer Has better sensitivity. Less energy is needed from source. Completes a scan in 1 to 2 seconds. Takes several scans and averages them. Has a laser beam that keeps the instrument accurately calibrated.

17 Carbon-Carbon (C-C) Bond Stretching Stronger bonds absorb at higher frequencies: C-C 1200 cm -1 C=C 1660 cm -1 C C 2200 cm -1 (weak or absent if internal) Conjugation lowers the frequency: isolated C=C cm -1 conjugated C=C cm -1 aromatic C=C approx cm -1 => Chapter 12 17

18 Chapter 12 18

19 Carbon-Hydrogen (C-H) Stretching Bonds with more s character absorb at a higher frequency. sp 3 C-H, just below 3000 cm -1 (to the right) sp 2 C-H, just above 3000 cm -1 (to the left) sp C-H, at 3300 cm -1 => Chapter 12 19

20 Examples Chapter 12 20

21 An Alkane IR Spectrum n >3000; d 1465, 1375 Chapter =>

22 An Alkene IR Spectrum Chapter =>

23 An Alkyne IR Spectrum Chapter =>

24 O-H and N-H Stretching Both of these occur around 3300 cm -1, but they look different. Alcohol O-H, broad with rounded tip. Secondary amine (R 2 NH), broad with one sharp spike. Primary amine (RNH 2 ), broad with two sharp spikes. No signal for a tertiary amine (R 3 N) => Chapter 12 24

25 Chapter 12 25

26 Chapter 12 26

27 The O-H stretching absorption is very characteristic In very dilute solutions, hydrogen bonding is absent and there is a very sharp peak at cm -1 In more concentrated solutions, the hydroxyl groups hydrogen bond to each other and a very broad and large peak occurs at cm -1 Chapter 12 27

28 An Alcohol IR Spectrum Chapter =>

29 An Amine IR Spectrum Chapter =>

30 Carbonyl(n C=O) Stretching The C=O bond of simple ketones, aldehydes, and carboxylic acids absorb around n 1710 cm -1. => Chapter 12 30

31 Usually, it s the strongest IR signal. Carboxylic acids will have O-H also. Aldehydes have two C-H signals around 2700 and 2800 cm -1. Chapter 12 31

32 A Ketone IR Spectrum Chapter =>

33 An Aldehyde (n HC=O) IR Spectrum Chapter =>

34 O-H Stretch of a Carboxylic Acid This O-H absorbs broadly, cm -1, due to strong hydrogen bonding. Chapter =>

35 Variations in C=O Absorption Conjugation of C=O with C=C lowers the stretching frequency to ~1680 cm -1. The C=O group of an amide absorbs at an even lower frequency, cm -1. The C=O of an ester absorbs at a higher frequency, ~ cm -1. Carbonyl groups in small rings (5 C s or less) absorb at an even higher frequency. => Chapter 12 35

36 Chapter 12 36

37 習 題 Portions of the infrared spectra of three cyclic ketones and three exocyclic alkenes show the influence of ring strain on the C=O and C=C stretching frequency. Please indicate your combination and explain your reasons. H 2 C O CH 2 O CH 2 O Chapter 12 37

38 習 題 The C=O vibration frequencies are varied to different molecules which reveals the influence of conjugation and other factors. Show the order of the carbonyl absorption of the following molecules and explain your reasons for full credits. (I) (II) (III) O O O O O OH O CH 3 (IV) O (V) O O CH 3 O CH 3 Chapter 12 38

39 An Amide IR Spectrum Chapter =>

40 習 題 The absorption of carbonyl group in amide is usually in the range from 1680 to 1630 cm -1. However, the following compound has the C=O band appearing about 1700cm -1. Please explain this observation. N C=O:1700cm -1 O Chapter 12 40

41 Carbon - Nitrogen Stretching (C~N) C - N absorbs around 1200 cm -1. C = N absorbs around 1660 cm -1 and is much stronger than the C = C absorption in the same region. C N absorbs strongly just above 2200 cm -1. The alkyne C C signal is much weaker and is just below 2200 cm -1. => Chapter 12 41

42 A Nitrile IR Spectrum Chapter =>

43 Chapter 12 43

44 Summary of IR Absorptions Chapter => =>

45 TODAY S CHEMIST AT WORK Chapter 12 45

46 In addition to the physical symptoms, diseases cause changes in the chemical composition of the organs,tissues, or fluids they affect; these differences are the basis of everyday clinical chemical tests, tissue staining, and medical imaging techniques. IR spectroscopy not only probes the chemical composition of a sample but also determines the precise position and amplitude of IR absorption bands that reflect interactions among the matrix constituents. Because of its sensitivity to both molecular structure and molecular interactions, the spectrum is often referred to as a molecular fingerprint of the sample; the specificity of that fingerprint is the basis for biomedical applications. Chapter 12 46

47 Strengths and Limitations IR alone cannot determine a structure. Some signals may be ambiguous. The functional group is usually indicated. The absence of a signal is definite proof that the functional group is absent. Correspondence with a known sample s IR spectrum confirms the identity of the compound. => Chapter 12 47

DETERMINACIÓN DE ESTRUCTURAS ORGÁNICAS (ORGANIC SPECTROSCOPY) IR SPECTROSCOPY

DETERMINACIÓN DE ESTRUCTURAS ORGÁNICAS (ORGANIC SPECTROSCOPY) IR SPECTROSCOPY DETERMINACIÓN DE ESTRUCTURAS ORGÁNICAS (ORGANIC SPECTROSCOPY) IR SPECTROSCOPY Hermenegildo García Gómez Departamento de Química Instituto de Tecnología Química Universidad Politécnica de Valencia 46022

More information

Introduction. Chapter 12 Mass Spectrometry and Infrared Spectroscopy. Electromagnetic Spectrum. Types of Spectroscopy 8/29/2011

Introduction. Chapter 12 Mass Spectrometry and Infrared Spectroscopy. Electromagnetic Spectrum. Types of Spectroscopy 8/29/2011 Organic Chemistry, 6 th Edition L. G. Wade, Jr. Chapter 12 Mass Spectrometry and Infrared Spectroscopy Introduction Spectroscopy is an analytical technique which helps determine structure. It destroys

More information

CHAPTER 12 INFRARED SPECTROSCOPY. and MASS SPECTROSCOPY

CHAPTER 12 INFRARED SPECTROSCOPY. and MASS SPECTROSCOPY KOT 222 ORGANIC CHEMISTRY II CHAPTER 12 INFRARED SPECTROSCOPY and MASS SPECTROSCOPY Part I Infrared Spectroscopy What is Spectroscopy? Spectroscopy is the study of the interaction of matter and electromagnetic

More information

INFRARED SPECTROSCOPY (IR)

INFRARED SPECTROSCOPY (IR) INFRARED SPECTROSCOPY (IR) Theory and Interpretation of IR spectra ASSIGNED READINGS Introduction to technique 25 (p. 833-834 in lab textbook) Uses of the Infrared Spectrum (p. 847-853) Look over pages

More information

Infrared Spectroscopy and Mass Spectrometry

Infrared Spectroscopy and Mass Spectrometry Infrared Spectroscopy and Mass Spectrometry Introduction It is fundamental for an organic chemist to be able to identify, or characterize, the new compound that he/she has just made. Sometimes this can

More information

Determining the Structure of an Organic Compound

Determining the Structure of an Organic Compound Determining the Structure of an Organic Compound The analysis of the outcome of a reaction requires that we know the full structure of the products as well as the reactants In the 19 th and early 20 th

More information

Symmetric Stretch: allows molecule to move through space

Symmetric Stretch: allows molecule to move through space BACKGROUND INFORMATION Infrared Spectroscopy Before introducing the subject of IR spectroscopy, we must first review some aspects of the electromagnetic spectrum. The electromagnetic spectrum is composed

More information

Organic Chemistry Tenth Edition

Organic Chemistry Tenth Edition Organic Chemistry Tenth Edition T. W. Graham Solomons Craig B. Fryhle Welcome to CHM 22 Organic Chemisty II Chapters 2 (IR), 9, 3-20. Chapter 2 and Chapter 9 Spectroscopy (interaction of molecule with

More information

Chapter 13 Mass Spectrometry and Infrared Spectroscopy

Chapter 13 Mass Spectrometry and Infrared Spectroscopy Chapter 13 Mass Spectrometry and Infrared Spectroscopy Copyright 2011 The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Overview of Mass Spectrometry Mass spectrometry

More information

II cm -1. Carbon hydrogen bonds absorb here. Alkanes absorb cm-1, Akene C-H cm-1 Aromatic C-H shorter and spikey

II cm -1. Carbon hydrogen bonds absorb here. Alkanes absorb cm-1, Akene C-H cm-1 Aromatic C-H shorter and spikey How to Interpret an IR Spectrum The IR may be broken down into 5 distinct regions. I. 3100-3600cm -1. Alcohols, Carboxylic Acids, Amines and Terminal Alkynes absorb here. The shape and exact location of

More information

Lecture Topics: I. IR spectroscopy

Lecture Topics: I. IR spectroscopy IR and Mass Spectrometry Reading: Wade chapter 12, sections 12-1- 12-15 Study Problems: 12-15, 12-16, 12-23, 12-25 Key Concepts and Skills: Given an IR spectrum, identify the reliable characteristic peaks

More information

Infrared Spectroscopy

Infrared Spectroscopy Infrared Spectroscopy 1 Chap 12 Reactions will often give a mixture of products: OH H 2 SO 4 + Major Minor How would the chemist determine which product was formed? Both are cyclopentenes; they are isomers.

More information

passing through (Y-axis). The peaks are those shown at frequencies when less than

passing through (Y-axis). The peaks are those shown at frequencies when less than Infrared Spectroscopy used to analyze the presence of functional groups (bond types) in organic molecules The process for this analysis is two-fold: 1. Accurate analysis of infrared spectra to determine

More information

Look for absorption bands in decreasing order of importance:

Look for absorption bands in decreasing order of importance: Infrared spectra: It is important to remember that the absence of an absorption band can often provide more information about the structure of a compound than the presence of a band. Be careful to avoid

More information

Absorption of IR Light

Absorption of IR Light Absorption of IR Light Absorption of IR light causes changes in the vibrational motions of a molecule. The different vibrational modes available to a molecule include stretching and bending modes. The

More information

For example: (Example is from page 50 of the Thinkbook)

For example: (Example is from page 50 of the Thinkbook) SOLVING COMBINED SPECTROSCOPY PROBLEMS: Lecture Supplement: page 50-53 in Thinkbook CFQ s and PP s: page 216 241 in Thinkbook Introduction: The structure of an unknown molecule can be determined using

More information

HOMEWORK PROBLEMS: IR SPECTROSCOPY AND 13C NMR. The peak at 1720 indicates a C=O bond (carbonyl). One possibility is acetone:

HOMEWORK PROBLEMS: IR SPECTROSCOPY AND 13C NMR. The peak at 1720 indicates a C=O bond (carbonyl). One possibility is acetone: HMEWRK PRBLEMS: IR SPECTRSCPY AND 13C NMR 1. You find a bottle on the shelf only labeled C 3 H 6. You take an IR spectrum of the compound and find major peaks at 2950, 1720, and 1400 cm -1. Draw a molecule

More information

for excitation to occur, there must be an exact match between the frequency of the applied radiation and the frequency of the vibration

for excitation to occur, there must be an exact match between the frequency of the applied radiation and the frequency of the vibration ! = 1 2"c k (m + M) m M wavenumbers! =!/c = 1/" wavelength frequency! units: cm 1 for excitation to occur, there must be an exact match between the frequency of the applied radiation and the frequency

More information

How to Interpret an IR Spectrum

How to Interpret an IR Spectrum How to Interpret an IR Spectrum Don t be overwhelmed when you first view IR spectra or this document. We have simplified the interpretation by having you only focus on 4/5 regions of the spectrum. Do not

More information

Organic Spectroscopy. UV - Ultraviolet-Visible Spectroscopy. !! 200-800 nm. Methods for structure determination of organic compounds:

Organic Spectroscopy. UV - Ultraviolet-Visible Spectroscopy. !! 200-800 nm. Methods for structure determination of organic compounds: Organic Spectroscopy Methods for structure determination of organic compounds: X-ray rystallography rystall structures Mass spectroscopy Molecular formula -----------------------------------------------------------------------------

More information

CHEM 51LB EXP 1 SPECTROSCOPIC METHODS: INFRARED AND NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

CHEM 51LB EXP 1 SPECTROSCOPIC METHODS: INFRARED AND NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY CHEM 51LB EXP 1 SPECTRSCPIC METHDS: INFRARED AND NUCLEAR MAGNETIC RESNANCE SPECTRSCPY REACTINS: None TECHNIQUES: IR Spectroscopy, NMR Spectroscopy Infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy

More information

CHEM1002 Worksheet 4: Spectroscopy Workshop (1)

CHEM1002 Worksheet 4: Spectroscopy Workshop (1) CHEM1002 Worksheet 4: Spectroscopy Workshop (1) This worksheet forms part of the Spectroscopy Problem Solving Assignment which represents 10% of the assessment of this unit. You should use the support

More information

Experiment 11. Infrared Spectroscopy

Experiment 11. Infrared Spectroscopy Chem 22 Spring 2010 Experiment 11 Infrared Spectroscopy Pre-lab preparation. (1) In Ch 5 and 12 of the text you will find examples of the most common functional groups in organic molecules. In your notebook,

More information

Ultraviolet Spectroscopy

Ultraviolet Spectroscopy Ultraviolet Spectroscopy The wavelength of UV and visible light are substantially shorter than the wavelength of infrared radiation. The UV spectrum ranges from 100 to 400 nm. A UV-Vis spectrophotometer

More information

electron does not become part of the compound; one electron goes in but two electrons come out.

electron does not become part of the compound; one electron goes in but two electrons come out. Characterization Techniques for Organic Compounds. When we run a reaction in the laboratory or when we isolate a compound from nature, one of our first tasks is to identify the compound that we have obtained.

More information

MOLECULAR REPRESENTATIONS AND INFRARED SPECTROSCOPY

MOLECULAR REPRESENTATIONS AND INFRARED SPECTROSCOPY MLEULAR REPRESENTATINS AND INFRARED SPETRSPY A STUDENT SULD BE ABLE T: 1. Given a Lewis (dash or dot), condensed, bond-line, or wedge formula of a compound draw the other representations. 2. Give examples

More information

Interpreting Infrared Spectra Painlessly, Quickly, and Correctly

Interpreting Infrared Spectra Painlessly, Quickly, and Correctly Interpreting Infrared Spectra Painlessly, Quickly, and Correctly Knowing how to interpret infrared (IR) spectra is of immense help to structure determination. Not only will it tell you what functional

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Exam Name 1) Which compound would be expected to show intense IR absorption at 3300 cm-1? A) butane B) CH3CH2C CH C)CH3C CCH3 D) but-1-ene 1) 2) Which compound would be expected to show intense IR absorption

More information

Infrared Spectroscopy: Theory

Infrared Spectroscopy: Theory u Chapter 15 Infrared Spectroscopy: Theory An important tool of the organic chemist is Infrared Spectroscopy, or IR. IR spectra are acquired on a special instrument, called an IR spectrometer. IR is used

More information

How to Quickly Solve Spectrometry Problems

How to Quickly Solve Spectrometry Problems How to Quickly Solve Spectrometry Problems You should be looking for: Mass Spectrometry (MS) Chemical Formula DBE Infrared Spectroscopy (IR) Important Functional Groups o Alcohol O-H o Carboxylic Acid

More information

13C NMR Spectroscopy

13C NMR Spectroscopy 13 C NMR Spectroscopy Introduction Nuclear magnetic resonance spectroscopy (NMR) is the most powerful tool available for structural determination. A nucleus with an odd number of protons, an odd number

More information

CHEM 51LB: EXPERIMENT 5 SPECTROSCOPIC METHODS: INFRARED AND NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

CHEM 51LB: EXPERIMENT 5 SPECTROSCOPIC METHODS: INFRARED AND NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY CHEM 51LB: EXPERIMENT 5 SPECTROSCOPIC METHODS: INFRARED AND NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY REACTIONS: None TECHNIQUES: IR, NMR Infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy are

More information

Chapter 13 Spectroscopy NMR, IR, MS, UV-Vis

Chapter 13 Spectroscopy NMR, IR, MS, UV-Vis Chapter 13 Spectroscopy NMR, IR, MS, UV-Vis Main points of the chapter 1. Hydrogen Nuclear Magnetic Resonance a. Splitting or coupling (what s next to what) b. Chemical shifts (what type is it) c. Integration

More information

ANALYSIS OF ASPIRIN INFRARED (IR) SPECTROSCOPY AND MELTING POINT DETERMINATION

ANALYSIS OF ASPIRIN INFRARED (IR) SPECTROSCOPY AND MELTING POINT DETERMINATION Chem 306 Section (Circle) M Tu W Th Name Partners Date ANALYSIS OF ASPIRIN INFRARED (IR) SPECTROSCOPY AND MELTING POINT DETERMINATION Materials: prepared acetylsalicylic acid (aspirin), stockroom samples

More information

UV-Visible Spectroscopy

UV-Visible Spectroscopy UV-Visible Spectroscopy UV-Visible Spectroscopy What is UV-Visible Spectroscopy? Molecular spectroscopy that involves study of the interaction of Ultra violet (UV)-Visible radiation with molecules What

More information

Nuclear Magnetic Resonance Spectroscopy

Nuclear Magnetic Resonance Spectroscopy Nuclear Magnetic Resonance Spectroscopy Nuclear magnetic resonance spectroscopy is a powerful analytical technique used to characterize organic molecules by identifying carbonhydrogen frameworks within

More information

(3)

(3) 1. Organic compounds are often identified by using more than one analytical technique. Some of these techniques were used to identify the compounds in the following reactions. C 3 H 7 Br C 3 H 8 O C 3

More information

E35 SPECTROSCOPIC TECHNIQUES IN ORGANIC CHEMISTRY

E35 SPECTROSCOPIC TECHNIQUES IN ORGANIC CHEMISTRY E35 SPECTRSCPIC TECNIQUES IN RGANIC CEMISTRY TE TASK To use mass spectrometry and IR, UV/vis and NMR spectroscopy to identify organic compounds. TE SKILLS By the end of the experiment you should be able

More information

Organic Spectroscopy

Organic Spectroscopy 1 Organic Spectroscopy Second Year, Michaelmas term, 8 lectures: Dr TDW Claridge & Prof BG Davis Lectures 1 4 highlight the importance of spectroscopic methods in the structural elucidation of organic

More information

Chapter 25 The Chemistry of Life: Organic Chemistry. 25.1 Some General Characteristics of Organic Molecules

Chapter 25 The Chemistry of Life: Organic Chemistry. 25.1 Some General Characteristics of Organic Molecules Chapter 25 The Chemistry of Life: Organic Chemistry general characteristics of organic molecules introduction to hydrocarbons alkanes unsaturated hydrocarbons functional groups: alcohols and ethers compounds

More information

Vibrational Spectroscopy Functional Groups

Vibrational Spectroscopy Functional Groups hem 325 Vibrational Spectroscopy Functional roups Bonds to - single N- single - single egions of the I Spectrum The I spectrum normally spans the 4000 cm -1 to 400 cm -1 range (2500 nm to 25000 nm). This

More information

0 10 20 30 40 50 60 70 m/z

0 10 20 30 40 50 60 70 m/z Mass spectrum for the ionization of acetone MS of Acetone + Relative Abundance CH 3 H 3 C O + M 15 (loss of methyl) + O H 3 C CH 3 43 58 0 10 20 30 40 50 60 70 m/z It is difficult to identify the ions

More information

Organic Spectroscopy 1 Michaelmas Lecture 6 Dr Rob Paton.

Organic Spectroscopy 1 Michaelmas Lecture 6 Dr Rob Paton. rganic Spectroscopy 1 Michaelmas 2011 Lecture 6 Dr ob Paton robert.paton@chem.ox.ac.uk http://paton.chem.ox.ac.uk 1 ecap of Lecture 5 UV-vis Spectroscopy Measures the gaps between electronic energy levels

More information

where h = 6.62 10-34 J s

where h = 6.62 10-34 J s Electromagnetic Spectrum: Refer to Figure 12.1 Molecular Spectroscopy: Absorption of electromagnetic radiation: The absorptions and emissions of electromagnetic radiation are related molecular-level phenomena

More information

Solving Spectroscopy Problems

Solving Spectroscopy Problems Solving Spectroscopy Problems The following is a detailed summary on how to solve spectroscopy problems, key terms are highlighted in bold and the definitions are from the illustrated glossary on Dr. Hardinger

More information

12.4 FUNCTIONAL-GROUP INFRARED ABSORPTIONS

12.4 FUNCTIONAL-GROUP INFRARED ABSORPTIONS 552 APTER 12 INTRODUTION TO SPETROSOPY. INFRARED SPETROSOPY AND MASS SPETROMETRY PROBLEM 12.9 Which of the following vibrations should be infrared-active and which should be infrared-inactive (or nearly

More information

CHEMISTRY 251 Spectroscopy Problems

CHEMISTRY 251 Spectroscopy Problems EMISTRY 251 Spectroscopy Problems The IR below is most likely of a: aldehyde alkane alkene alkyl bromide alkyne The IR below is most likely of a: acyl chloride alcohol 3 amide ether nitrile The IR spectrum

More information

Organic Chemistry. O1: Ways of representing organic molecules. Dr Amanda Rousseau C503. 1. Molecular formula

Organic Chemistry. O1: Ways of representing organic molecules. Dr Amanda Rousseau C503. 1. Molecular formula O1: Ways of representing organic molecules Organic Chemistry Dr Amanda Rousseau C503 Chemistry the Central Science - Brown (Chapter 24) Extra reading: Organic Chemistry McMurry (any edition) Self study:

More information

By far the most important and useful technique to identify organic molecules. Often the only technique necessary.

By far the most important and useful technique to identify organic molecules. Often the only technique necessary. Chapter 13: NMR Spectroscopy 39 NMR Spectroscopy By far the most important and useful technique to identify organic molecules. Often the only technique necessary. NMR spectrum can be recorded for many

More information

Chapter 16: Infrared Spectroscopy

Chapter 16: Infrared Spectroscopy Where relevant, each IR spectrum will include the corresponding molecular structure. Chapter 16: Infrared Spectroscopy 16.1 Why Should I Study This? Spectroscopy is the study of the interaction of energy

More information

Typical Infrared Absorption Frequencies. Functional Class Range (nm) Intensity Assignment Range (nm) Intensity Assignment

Typical Infrared Absorption Frequencies. Functional Class Range (nm) Intensity Assignment Range (nm) Intensity Assignment Typical Infrared Absorption Frequencies Functional Class Range (nm) Intensity Assignment Range (nm) Intensity Assignment Alkanes 2850-3000 CH 3, CH 2 & CH 2 or 3 bands Alkenes 3020-3100 1630-1680 1900-2000

More information

Suggested solutions for Chapter 3

Suggested solutions for Chapter 3 s for Chapter PRBLEM Assuming that the molecular ion is the base peak (00% abundance) what peaks would appear in the mass spectrum of each of these molecules: (a) C5Br (b) C60 (c) C64Br In cases (a) and

More information

Spectroscopy. The Interaction of Electromagnetic Radiation (Light) with Molecules

Spectroscopy. The Interaction of Electromagnetic Radiation (Light) with Molecules Spectroscopy. The Interaction of Electromagnetic Radiation (Light) with Molecules (1) Electromagnetic Radiation-wave description propagation c = 3 x 10 10 cm/sec magnetic () and electric (E) field vectors

More information

Chapter 5 Organic Spectrometry

Chapter 5 Organic Spectrometry Chapter 5 Organic Spectrometry from Organic Chemistry by Robert C. Neuman, Jr. Professor of Chemistry, emeritus University of California, Riverside orgchembyneuman@yahoo.com

More information

Determination of Molecular Structure by MOLECULAR SPECTROSCOPY

Determination of Molecular Structure by MOLECULAR SPECTROSCOPY Determination of Molecular Structure by MOLEULAR SPETROSOPY hemistry 3 B.Z. Shakhashiri Fall 29 Much of what we know about molecular structure has been learned by observing and analyzing how electromagnetic

More information

NMR is the most powerful structure determination tool available to organic chemists.

NMR is the most powerful structure determination tool available to organic chemists. Nuclear Magnetic esonance (NM) Spectrometry NM is the most powerful structure determination tool available to organic chemists. An NM spectrum provides information about: 1. The number of atoms of a given

More information

IR Applied to Isomer Analysis

IR Applied to Isomer Analysis DiscovIR-LC TM Application Note 025 April 2008 Deposition and Detection System IR Applied to Isomer Analysis Infrared spectra provide valuable information about local configurations of atoms in molecules.

More information

Department of Chemistry College of Science Sultan Qaboos University. Topics and Learning Outcomes

Department of Chemistry College of Science Sultan Qaboos University. Topics and Learning Outcomes Department of Chemistry College of Science Sultan Qaboos University Title : CHEM 3326 (Applied Spectroscopy) Credits : 3 Course Format : 2 lectures and 2 tutorials Course Text : Spectrometric Identification

More information

Used to determine relative location of atoms within a molecule Most helpful spectroscopic technique in organic chemistry Related to MRI in medicine

Used to determine relative location of atoms within a molecule Most helpful spectroscopic technique in organic chemistry Related to MRI in medicine Structure Determination: Nuclear Magnetic Resonance CHEM 241 UNIT 5C 1 The Use of NMR Spectroscopy Used to determine relative location of atoms within a molecule Most helpful spectroscopic technique in

More information

Identifying an Unknown Substance using Infrared Spectroscopy (IR), Carbon-13 Nuclear Magnetic Resonance ( 13 C NMR), and Proton Nuclear Magnetic

Identifying an Unknown Substance using Infrared Spectroscopy (IR), Carbon-13 Nuclear Magnetic Resonance ( 13 C NMR), and Proton Nuclear Magnetic Identifying an Unknown Substance using Infrared Spectroscopy (I), arbon-13 Nuclear Magnetic esonance ( 13 NM), and Proton Nuclear Magnetic esonance ( 1 NM) Identifying an Unknown Substance using Infrared

More information

Survival Organic Chemistry Part I: Molecular Models

Survival Organic Chemistry Part I: Molecular Models Survival Organic Chemistry Part I: Molecular Models The goal in this laboratory experience is to get you so you can easily and quickly move between empirical formulas, molecular formulas, condensed formulas,

More information

H NMR (proton NMR): determines number and type of H atoms 13. C NMR (proton NMR): determines number and type of C atoms

H NMR (proton NMR): determines number and type of H atoms 13. C NMR (proton NMR): determines number and type of C atoms 14.1 An Introduction to NMR Spectroscopy A. The Basics of Nuclear Magnetic Resonance (NMR) Spectroscopy nuclei with odd atomic number have a S = ½ with two spin states (+1/2 and -1/2) 1 H NMR (proton NMR):

More information

Proton Nuclear Magnetic Resonance Spectroscopy

Proton Nuclear Magnetic Resonance Spectroscopy Proton Nuclear Magnetic Resonance Spectroscopy Introduction: The NMR Spectrum serves as a great resource in determining the structure of an organic compound by revealing the hydrogen and carbon skeleton.

More information

Wave Properties of Electromagnetic Radiation

Wave Properties of Electromagnetic Radiation Wave Properties of Electromagnetic Radiation Two options are available for analytical utility when an analyte interacts with a beam of electromagnetic radiation in an instrument 1. We can monitor the changes

More information

The Fundamentals of Infrared Spectroscopy. Joe Van Gompel, PhD

The Fundamentals of Infrared Spectroscopy. Joe Van Gompel, PhD TN-100 The Fundamentals of Infrared Spectroscopy The Principles of Infrared Spectroscopy Joe Van Gompel, PhD Spectroscopy is the study of the interaction of electromagnetic radiation with matter. The electromagnetic

More information

Time out states and transitions

Time out states and transitions Time out states and transitions Spectroscopy transitions between energy states of a molecule excited by absorption or emission of a photon hn = DE = E i - E f Energy levels due to interactions between

More information

Application Note AN4

Application Note AN4 TAKING INVENTIVE STEPS IN INFRARED. MINIATURE INFRARED GAS SENSORS GOLD SERIES UK Patent App. No. 2372099A USA Patent App. No. 09/783,711 World Patents Pending INFRARED SPECTROSCOPY Application Note AN4

More information

Interpretation of Experimental Data

Interpretation of Experimental Data Lab References When evaluating experimental data it is important to recognize what the data you are collecting is telling you, as well as the strengths and limitations of each method you are using. Additionally,

More information

Chapter 11 Structure Determination: Nuclear Magnetic Resonance Spectroscopy. Nuclear Magnetic Resonance Spectroscopy. 11.1 Nuclear Magnetic Resonance

Chapter 11 Structure Determination: Nuclear Magnetic Resonance Spectroscopy. Nuclear Magnetic Resonance Spectroscopy. 11.1 Nuclear Magnetic Resonance John E. McMurry http://www.cengage.com/chemistry/mcmurry Chapter 11 Structure Determination: Nuclear Magnetic Resonance Spectroscopy 11.1 Nuclear Magnetic Resonance Spectroscopy Many atomic nuclei behave

More information

Molecular Formula Determination

Molecular Formula Determination Molecular Formula Determination Classical Approach Qualitative elemental analysis Quantitative elemental analysis Determination of empirical formula Molecular weight determination Molecular formula determination

More information

Chemical Shift (δ) 0 (by definition) 0.8-1.0 1.2-1.4 1.4-1.7 1.6-2.6 2.0-3.0 2.2-2.5 2.3-2.8 0.5-6.0 3.4-4.0 3.3-4.0 0.5-5.0

Chemical Shift (δ) 0 (by definition) 0.8-1.0 1.2-1.4 1.4-1.7 1.6-2.6 2.0-3.0 2.2-2.5 2.3-2.8 0.5-6.0 3.4-4.0 3.3-4.0 0.5-5.0 Chemical Shifts 1 H-NMR Type of Hydrogen (CH 3 ) 4 Si RCH 3 RCH 2 R R 3 CH R 2 C=CRCHR 2 RC CH ArCH 3 ArCH 2 R ROH RCH 2 OH RCH 2 OR R 2 NH O RCCH 3 O RCCH 2 R Chemical Shift (δ) 0 (by definition) 0.8-1.0

More information

Electromagnetic Radiation

Electromagnetic Radiation Activity 17 Electromagnetic Radiation Why? Electromagnetic radiation, which also is called light, is an amazing phenomenon. It carries energy and has characteristics of both particles and waves. We can

More information

Shielding and Chemical Shift. Figure 14.3

Shielding and Chemical Shift. Figure 14.3 Shielding and Chemical Shift Figure 14.3 1 Summary of Shielding Figure 14.4 2 Shielding and Signal Position 3 Characteristic Chemical Shifts Protons in a given environment absorb in a predictable region

More information

Background A nucleus with an odd atomic number or an odd mass number has a nuclear spin that can be observed by NMR spectrometers.

Background A nucleus with an odd atomic number or an odd mass number has a nuclear spin that can be observed by NMR spectrometers. NMR Spectroscopy I Reading: Wade chapter, sections -- -7 Study Problems: -, -7 Key oncepts and Skills: Given an structure, determine which protons are equivalent and which are nonequivalent, predict the

More information

Yin and Yang in Chemistry Education: The Complementary Nature of FT-IR and NMR Spectroscopies

Yin and Yang in Chemistry Education: The Complementary Nature of FT-IR and NMR Spectroscopies Yin and Yang in Chemistry Education: The Complementary Nature of FT-IR and NMR Spectroscopies Matthew Gundlach, Katherine Paulsen, Michael Garry, Steve Lowry, Thermo Fisher Scientific, Madison, WI USA

More information

EXPERIMENT 1: Survival Organic Chemistry: Molecular Models

EXPERIMENT 1: Survival Organic Chemistry: Molecular Models EXPERIMENT 1: Survival Organic Chemistry: Molecular Models Introduction: The goal in this laboratory experience is for you to easily and quickly move between empirical formulas, molecular formulas, condensed

More information

PROTON NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY (H-NMR)

PROTON NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY (H-NMR) PROTON NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY (H-NMR) WHAT IS H-NMR SPECTROSCOPY? References: Bruice 14.1, 14.2 Introduction NMR or nuclear magnetic resonance spectroscopy is a technique used to determine

More information

Chapter 2 Electromagnetic Radiation

Chapter 2 Electromagnetic Radiation Chapter 2 Electromagnetic Radiation Bohr demonstrated that information about the structure of hydrogen could be gained by observing the interaction between thermal energy (heat) and the atom. Many analytical

More information

Chapter 10 Introduction to Organic Chemistry: Alkanes. Organic Chemistry. 10.1 Organic Compounds. Organic vs. Inorganic.

Chapter 10 Introduction to Organic Chemistry: Alkanes. Organic Chemistry. 10.1 Organic Compounds. Organic vs. Inorganic. Chapter 10 Introduction to Organic Chemistry: Alkanes 10.1 Organic Compounds Organic Chemistry An organic compound is a compound made from carbon atoms. has one or more C atoms. has many H atoms. may also

More information

The Four Questions to Ask While Interpreting Spectra. 1. How many different environments are there?

The Four Questions to Ask While Interpreting Spectra. 1. How many different environments are there? 1 H NMR Spectroscopy (#1c) The technique of 1 H NMR spectroscopy is central to organic chemistry and other fields involving analysis of organic chemicals, such as forensics and environmental science. It

More information

Organic Spectroscopy

Organic Spectroscopy Organic Spectroscopy Chem 744 / 754 Spring 2013 Gregory R. Cook Web Page cook.chem.ndsu.nodak.edu 2 Resources Books on reserve in the Library Introduction to Spectroscopy 3rd Ed., Pavia, Lampman, Kriz;

More information

Monday, September 10th

Monday, September 10th Monday, September 10th Review Chapter 11 iclicker Quiz #1 Chapter 12 Chapter 13(maybe) Group assignment Keep checking the class webpage at www.bhsu.edu/danasunskis. Go to the course tab then CHEM107 Lecture

More information

Problem Set 3 Solutions CH332 (SP 06) 1. Skoog problem 15-1 (omit terms (j), (k) and (m)). Draw diagrams as necessary.

Problem Set 3 Solutions CH332 (SP 06) 1. Skoog problem 15-1 (omit terms (j), (k) and (m)). Draw diagrams as necessary. Problem Set 3 Solutions CH332 (SP 06) 1. Skoog problem 15-1 (omit terms (j), (k) and (m)). Draw diagrams as necessary. a) fluorescence Relaxation of an excited state by emission of a photon without a change

More information

Analytical chemistry year 12

Analytical chemistry year 12 Analytical chemistry year 12 1) Consider the molecule on the right. a) How many sets of peaks are present in the 1 H NMR spectrum? 3 b) How many sets of peaks are present in the 13 C NMR spectrum? 4 c)

More information

NUCLEAR MAGNETIC RESONANCE AND INTRODUCTION TO MASS SPECTROMETRY

NUCLEAR MAGNETIC RESONANCE AND INTRODUCTION TO MASS SPECTROMETRY NUCLEAR MAGNETIC RESNANCE AND INTRDUCTIN T MASS SPECTRMETRY A STUDENT SHULD BE ABLE T: 1. Identify and explain the processes involved in proton and carbon-13 nuclear magnetic resonance (NMR), and mass

More information

Mass Spec - Fragmentation

Mass Spec - Fragmentation Mass Spec - Fragmentation An extremely useful result of EI ionization in particular is a phenomenon known as fragmentation. The radical cation that is produced when an electron is knocked out of a neutral

More information

Radical and Cation Stabilities Radical vs cation stabilities

Radical and Cation Stabilities Radical vs cation stabilities Mass Spectrometry and Free Radicals MS recap Positive mode of Electron Ionization / ESI MS sees charged species (M+, M+), but does not see uncharged (R ) Radical and Cation Stabilities Radical vs cation

More information

NMR Spectroscopy. Introduction

NMR Spectroscopy. Introduction Introduction NMR Spectroscopy Over the past fifty years nuclear magnetic resonance spectroscopy, commonly referred to as nmr, has become the most important technique for determining the structure of organic

More information

NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY NMR Spectroscopy F34 1 NULEAR MAGNETI RESONANE SPETROSOPY Involves interaction of materials with the low-energy radiowave region of the electromagnetic spectrum Origin of Spectra Theory All nuclei possess

More information

Nuclear Magnetic Resonance Spectroscopy

Nuclear Magnetic Resonance Spectroscopy Nuclear Magnetic Resonance Spectroscopy Introduction NMR is the most powerful tool available for organic structure determination. It is used to study a wide variety of nuclei: 1 H 13 C 15 N 19 F 31 P 2

More information

Time out states and transitions

Time out states and transitions Time out states and transitions Spectroscopy transitions between energy states of a molecule excited by absorption or emission of a photon hν = E = E i -E f Energy levels due to interactions between parts

More information

1) A compound gives a mass spectrum with peaks at m/z = 77 (40%), 112 (100%), 114 (33%), and essentially no other peaks. Identify the compound.

1) A compound gives a mass spectrum with peaks at m/z = 77 (40%), 112 (100%), 114 (33%), and essentially no other peaks. Identify the compound. 1) A compound gives a mass spectrum with peaks at m/z = 77 (40%), 112 (100%), 114 (33%), and essentially no other peaks. Identify the compound. First, your molecular ion peak is 112 and you have a M+2

More information

Types of Spectroscopy

Types of Spectroscopy Introduction to Infrared and Raman spectroscopy Arto Koistinen UEF / SIB-labs Optical microscopy course 2012 31.10.2012 Types of Spectroscopy = study of interaction between radiation and matter X-ray photoelectron

More information

3H CH 3 group 2H CH 2 group 1H CH or OH group

3H CH 3 group 2H CH 2 group 1H CH or OH group H NMR Spectroscopy and Interpretation: More Detailed than the Summary 89 Introduction to 1H-NMR Spectroscopy Hydrogen NMR spectroscopy is considerably more complex than 1-NMR. The interpretation is more

More information

Chapter 13 Nuclear Magnetic Resonance Spectroscopy

Chapter 13 Nuclear Magnetic Resonance Spectroscopy Organic Chemistry, 6 th Edition L. G. Wade, Jr. Chapter 13 Nuclear Magnetic Resonance Spectroscopy Jo Blackburn Richland College, Dallas, TX Dallas County Community College District 2006, Prentice Hall

More information

Chapter: Introduction to Organic Chemistry: Alkanes

Chapter: Introduction to Organic Chemistry: Alkanes Chapter: Introduction to Organic Chemistry: Alkanes Organic Chemistry An organic compound is a compound made from carbon atoms. has one or more C atoms. has many H atoms. may also contain O, S, N, and

More information

SPECTROSCOPY. NUCLEAR MAGNETIC RESONANCE (NMR) AND INFRARED (IR)

SPECTROSCOPY. NUCLEAR MAGNETIC RESONANCE (NMR) AND INFRARED (IR) EXPERIMENT 9 SPETRSPY. NULEAR MAGNETI RESNANE (NMR) AND INFRARED (IR) Materials Needed approx 100 mg of an ester synthesized in Expt #7 - (octyl acetate, benzyl acetate, or isopentyl acetate) approx 1

More information

Lab 6: Determination of Molecular Structure

Lab 6: Determination of Molecular Structure Lab 6: Determination of Molecular Structure Laboratory Goals In this lab, you will: Determine the infrared spectrum of a polymer sample Learn how to use a Fourier Transform Infrared Spectrometer to obtain

More information

Chapter 2 - Families of Carbon Compounds

Chapter 2 - Families of Carbon Compounds Andrew Rosen Chapter 2 - Families of Carbon Compounds 2.1 - Hydrocarbons: Representative Alkanes, Alkenes, Alkynes, and Aromatic Compounds - Hydrocarbons are compounds that contain only hydrogen and carbon

More information

AP Chemistry Chapter 22 - Organic and Biological Molecules

AP Chemistry Chapter 22 - Organic and Biological Molecules AP Chemistry Chapter - Organic and Biological Molecules.1 Alkanes: Saturated Hydrocarbons A. Straight-chain Hydrocarbons 1. Straight-chain alkanes have the formula C n H n+. Carbons are sp hybridized The

More information