A 13 C-NMR spectrum. RF Frequency The intensity of the peak doesn t does not necessarily correlate to the number of carbons.

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "A 13 C-NMR spectrum. RF Frequency The intensity of the peak doesn t does not necessarily correlate to the number of carbons."

Transcription

1 13 -NMR We can examine the nuclear magnetic properties of carbon atoms in a molecule to learn about a molecules structure. Most carbons are 12 ; 12 has an even number of protons and neutrons and cannot be observed by NMR techniques. nly 1% of carbons are 13, and these we can see in the NMR. This makes 13 -NMR much less senstive than carbon NMR. This affects the how we see splitting patterns.

2 A 13 -NMR spectrum. ere is what s cool about 13 -NMR: Different carbons appear at different frequencies! - Now you know how many different types of arbons you have! RF absorbance An internal standard called TMS is used to set the scale to zero RF Frequency The intensity of the peak doesn t does not necessarily correlate to the number of carbons.

3 Example: Two alcohols (- compound) with formula ID = 0 2. Possible structures: Same! 2 2 3

4 The -NMR spectrum of isopropanol only shows two different carbons! These two carbons are identical by symmetry:

5 ow Many 13 NMR resonances? 7 F 7 4 l F 4 F 7 F 2 3

6 = equivalent resonance structures 1 Br Br Br Br Br Br 2 l Br Br

7 An isolated 13 atoms have the same chemical shift. (resonate at the same frequency) Nucleus Electron cloud The electron cloud of the atom partially shields the nucleus from the surrounding magnetic field When the carbon nucleus is adjacent to an electronegative atom, the carbon nuclei has fewer Electrons around it. F Nuclei with less electron density around them will resonate at a different frequency: It requires shorter wavelength radio waves (or a weaker magnetic field) to cause a carbon nuclei to resonate if it has less electron density around it.

8 Typical Values of hemical shift depend on the 1. ybridization 2. Electronegativity of attached atom(s) aromatic Br, (l) carbonyl sp sp 40-5 sp Some specific values are included in tables Section IV your text book!

9 onversely atoms that donate electron density cause nuclei to resonate at lower frequencies (higher field strengths). 3 3 Si 3 The silicon in tetramethylsilane (TMS) shields the carbon nuclei and makes them appear up-field 3 The chemical shift spectrum is measured relative to TMS. Shift TMS

10 TE δ SALE IS USED T MEASURE EMIAL SIFT δ= is used to signify chemical shift. Because the frequency depends on the field strength, one uses a relative units scale of parts per million or ppm Shift TMS hemical shifts reported as ppm units give the same values for the same compound regardless of the instrument used! δ = (v (compound) - v (TMS) )/ v (TMS)

11 50.2 ppm ppm F l Br 71.6 ppm 25.6 ppm 9.6 ppm l l l l l l l l l l

12 4 6

13 4 6

14 3 6

15 13 peaks are in reality split by bonded protons. Generally shown like this: Actually looks like this: A doublet Why?? Adjacent nuclear spin of the proton locally increases magnetic field felt by carbon nuclei. arbons next to down proton spin arbons next to up proton spin NTE: There are only two possible peaks for s having one adjacent proton. or

16 Appears as quartet. There are eight possibilities: The general rule is: The number of peaks observed is equal to the number of attached protons, (N), plus one. Splitting = N+1 FR 13 it is the number of protons directly attached to the carbon that cause splitting.

17 PAY ATTENTIN!: 13-NMR Splitting pattern reflects how many protons are directly attached to the carbon atom A Triplett 1-NMR Splitting pattern reflects how many protons are connected to adjacent carbon atom(s) A doublet A Triplett The chances that my neighbor is also a -13 is 1/100 there is a 99% chance that the attached has a spin

18 We typically observe decoupled Spectra More sensitive! less confusing. 18 taken from Maitland Jones 3rd Ed.

19 Why don t the spins on adjacent arbons split each nly 1% of arbons have a spin! (Most are 12 and are NMR inactive). Therefore only 1 in ten thousand pairs of s have both have spin and are coupled. That s too small to detect!

20 Protons can couple (cause splitting) of -13 peaks but we don t see splitting of proton peaks by carbon!! - splitting is very small because only 1% of arbon has a spin!. You can see carbon-proton coupling if you look very closely! -13 satellites

21 Note all of these split peaks can quickly get confusing: Am I looking at two different carbon resonances or a single doublet? For this reason we show our spectra without splitting. But we often see the splitting indicated over the peak:

22 Account for ID! = = 6 10 ID =??? 2 SYMMETRY?No, same number of resonances as formula

23 3 9 N 44.6 (t) 27.4 (t) 11.5 (q) N 2

24 3 7 N 139 (d) 113 (t) 44.8 (t) N 2

25 3 9 N 43.0 (d) 26.5 (q) N 2

26 It is helpful to know what typical values of unfunctinalized s Approximate hemical Shifts ranges for unsubstituted Alkanes R R R R R R R R R R 5-22 ppm ppm 25-35ppm = 66-90ppm ppm

27 If your molecules containing xygen: ppm 50-75ppm (Similar to alcohol but two of them!) ppm R = alkyl X = l, Br, I R R R R R NR R X doublet but singlet! ~ N

28 If your molecule contains Nitrogen: Amines: N 2 N N ppm Nitro- N Imine N R ppm ~155 ppm N ~

29 (d) 67.7 (t) 18.7 (q)

30 8 8 ID Symmetry What is the doing? What other groups can you identify?

31 68 ID Symmetry What is the doing? What other groups can you identify? an you account for the ID?

32 4 7 l s t t q PPM l

33 5 8 s 2 t t t t PPM

34 ow do you take an NMR?? I. onstant Radio frequency but change magnetic field LD TRADITINAL WAY!! Magnetic Field Stronger Magnetic Field Energy No Field Max Tofield Rogers 1956 RF transmitter N DWN FIELD RF Receiver de-shielded S + - UP FIELD shielded Know these terms!!

35 Modern NMR spectra are obtained at constant field strength NSTANT MAGNETI FIELD!--hange Frequency No Absorbtion not enough energy Absorbtion Energies Match! No Absorbtion Energy too high

36 ENERGY FT-NMR RF-Pulse FYI different RF frequencies 13 Technically speaking: you don t selectively excite all the nuclei but rather you saturate the exchange of nuclei between the upper an lower energy states. At equilibrium (in the absence of the RF energy) there are slightly more nuclei in the lower energy state than in the upper energy state based on the normal Boltzman distributions. RF-Pulse

37 onsider the population of like-nuclei in a sample: FYI Irradiate Should be more in the ground state! wait hv

38 FYI hv Spin is conserved: When a nuclei changes spin, some other particle in the universe must also change spin. The coupling of spin is more efficient the closer the two particles are and if they are connected by bonds.

39 Different nuclei require different amounts of time to relax. WY??? FYI slowest fastest

40 DEPT (JVERT): APT (Attached Proton Test) experiment is not as sensitive as a DEPT experiment, the APT has FYI the advantage of seeing all carbons present: 0 at 145 ppm and 2 at 29 ppm are negative, while 3 at 16 ppm and in the range of ppm are positive. Thus c and b are negative, while a, d, e, and f are positive.spectrum of Ethyl Benzene: 3 2

41 FYI Presentation of Two Dimensional NMR

42 FYI

43 FYI

44 FYI

45 NMR is being used to determine the structure of small proteins. FYI

C NMR Spectroscopy C NMR. C Transition Energy

C NMR Spectroscopy C NMR. C Transition Energy NMR NMR Spectroscopy is the most abundant natural isotope of carbon, but has a nuclear spin I = 0, rendering it unobservable by NMR. Limited to the observation of the nucleus which constitutes only.% of

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

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

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

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

NMR Phenomenon. Nuclear Magnetic Resonance. µ A spinning charged particle generates a magnetic field.

NMR Phenomenon. Nuclear Magnetic Resonance. µ A spinning charged particle generates a magnetic field. NMR Phenomenon Nuclear Magnetic Resonance µ A spinning charged particle generates a magnetic field. A nucleus with a spin angular momentum will generate a magnetic moment (μ). If these tiny magnets are

More information

Chapter 16: NMR Spectroscopy (i.e., the most exciting thing on the planet)

Chapter 16: NMR Spectroscopy (i.e., the most exciting thing on the planet) Chapter 16: NMR Spectroscopy (i.e., the most exciting thing on the planet) ne day (soon), the following will make a lot of sense to you: 16.1-16.3 The Proton: An Unexpected Journey NMR: Like electrons,

More information

Nuclear Shielding and 1. H Chemical Shifts. 1 H NMR Spectroscopy Nuclear Magnetic Resonance

Nuclear Shielding and 1. H Chemical Shifts. 1 H NMR Spectroscopy Nuclear Magnetic Resonance NMR Spectroscopy Nuclear Magnetic Resonance Nuclear Shielding and hemical Shifts What do we mean by "shielding?" What do we mean by "chemical shift?" The electrons surrounding a nucleus affect the effective

More information

NMR SPECTROSCOPY A N I N T R O D U C T I O N T O... Self-study booklet NUCLEAR MAGNETIC RESONANCE. 4 3 2 1 0 δ PUBLISHING

NMR SPECTROSCOPY A N I N T R O D U C T I O N T O... Self-study booklet NUCLEAR MAGNETIC RESONANCE. 4 3 2 1 0 δ PUBLISHING A N I N T R O D U T I O N T O... NMR SPETROSOPY NULEAR MAGNETI RESONANE 4 3 1 0 δ Self-study booklet PUBLISING NMR Spectroscopy NULEAR MAGNETI RESONANE SPETROSOPY Origin of Spectra Theory All nuclei possess

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

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

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

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 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

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

TYPES OF INFORMATION FROM NMR SPECTRUM

TYPES OF INFORMATION FROM NMR SPECTRUM TYPES OF INFORMATION FROM NMR SPETRUM 1. Each different type of hydrogen gives a peak or group of peaks (multiplet). 2. The chemical shift (δ, in ppm) gives a clue as to the type of hydrogen generating

More information

Proton Nuclear Magnetic Resonance ( 1 H-NMR) Spectroscopy

Proton Nuclear Magnetic Resonance ( 1 H-NMR) Spectroscopy Proton Nuclear Magnetic Resonance ( 1 H-NMR) Spectroscopy Theory behind NMR: In the late 1940 s, physical chemists originally developed NMR spectroscopy to study different properties of atomic nuclei,

More information

Examination of Proton NMR Spectra

Examination of Proton NMR Spectra Examination of Proton NMR Spectra What to Look For 1) Number of Signals --- indicates how many "different kinds" of protons are present. 2) Positions of the Signals --- indicates something about magnetic

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

Nuclear Magnetic Resonance

Nuclear Magnetic Resonance Nuclear Magnetic Resonance NMR is probably the most useful and powerful technique for identifying and characterizing organic compounds. Felix Bloch and Edward Mills Purcell were awarded the 1952 Nobel

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

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

1 H and 13 C NMR compared: Both give information about the number of chemically nonequivalent nuclei (nonequivalent

1 H and 13 C NMR compared: Both give information about the number of chemically nonequivalent nuclei (nonequivalent 1 H and 13 C NMR compared: 13 C NMR Spectroscopy Both give information about the number of chemically nonequivalent nuclei (nonequivalent hydrogens or nonequivalent carbons) Both give information about

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

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

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

Nuclear Magnetic Resonance notes

Nuclear Magnetic Resonance notes Reminder: These notes are meant to supplement, not replace, the laboratory manual. Nuclear Magnetic Resonance notes Nuclear Magnetic Resonance (NMR) is a spectrometric technique which provides information

More information

Proton Nuclear Magnetic Resonance Spectroscopy

Proton Nuclear Magnetic Resonance Spectroscopy CHEM 334L Organic Chemistry Laboratory Revision 2.0 Proton Nuclear Magnetic Resonance Spectroscopy In this laboratory exercise we will learn how to use the Chemistry Department's Nuclear Magnetic Resonance

More information

4. It is possible to excite, or flip the nuclear magnetic vector from the α-state to the β-state by bridging the energy gap between the two. This is a

4. It is possible to excite, or flip the nuclear magnetic vector from the α-state to the β-state by bridging the energy gap between the two. This is a BASIC PRINCIPLES INTRODUCTION TO NUCLEAR MAGNETIC RESONANCE (NMR) 1. The nuclei of certain atoms with odd atomic number, and/or odd mass behave as spinning charges. The nucleus is the center of positive

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

Introduction to Nuclear Magnetic Resonance

Introduction to Nuclear Magnetic Resonance Reminder: These notes are meant to supplement, not replace, the textbook and laboratory manual. Introduction to Nuclear Magnetic Resonance (See also the Gas Chromatography notes, which also apply to today's

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

Chemical shift = observed chemical shift in MHz/ frequency of spectrometer (MHz)

Chemical shift = observed chemical shift in MHz/ frequency of spectrometer (MHz) Chapter 4. Physical Basis of NMR Spectroscopy. Today the most widely used method for determining the structure of organic compounds is nuclear magnetic resonance (NMR) spectroscopy. NMR spectroscopy involves

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 Chemistry Nuclear Magnetic Resonance H. D. Roth. Chemistry 307 Chapter 13 Nuclear Magnetic Resonance

Organic Chemistry Nuclear Magnetic Resonance H. D. Roth. Chemistry 307 Chapter 13 Nuclear Magnetic Resonance Chemistry 307 Chapter 13 Nuclear Magnetic Resonance Nuclear magnetic resonance (NMR) spectroscopy is one of three spectroscopic techniques that are useful tools for determining the structures of organic

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

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

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

Information contained in an NMR spectrum includes: 1. number of signals. Interpreting 1 H (Proton) NMR Spectra

Information contained in an NMR spectrum includes: 1. number of signals. Interpreting 1 H (Proton) NMR Spectra Information contained in an NMR spectrum includes: Interpreting 1 (Proton) NMR Spectra 1. number of signals 2. their intensity (as measured by area under peak) 3. splitting pattern (multiplicity) Number

More information

Now that we know why we re putting ourselves through the hassle of understanding all of this, let s get started with the analysis process.

Now that we know why we re putting ourselves through the hassle of understanding all of this, let s get started with the analysis process. 13 C -NMR: Cracking Those Carbons A little background: Protons, neutrons, and electrons all have something called spin. This doesn t mean that they re actually spinning around in tight circles like Olympian

More information

SIGNAL SPLITTING: Why are there so many peaks all in one area? This is called signal splitting. Example: (image from Illustrated Glossary, splitting)

SIGNAL SPLITTING: Why are there so many peaks all in one area? This is called signal splitting. Example: (image from Illustrated Glossary, splitting) Proton NMR Spectroscopy: Split the signals, not your brain! Before we can understand signal splitting, we have to understand what NMR is. This tutorial will first discuss a few concepts about NMR and then

More information

IV. Chemical Shifts - δ unit

IV. Chemical Shifts - δ unit Chem 215-216 W11 Notes - Dr. Masato Koreeda Date: January 5, 2011 Topic: _NMR-II page 1 of 10. IV. Chemical Shifts - δ unit Each nucleus in a molecule has a different degree of electron surrounding it.

More information

Chapter 15 NMR Spectroscopy

Chapter 15 NMR Spectroscopy Chempocalypse Now! Chapter 15 NMR Spectroscopy Page 1 Chapter 15 NMR Spectroscopy Parts of Topics A5 and A9 from the IB HL Chemistry Curriculum A5 A.5.1 Nuclear magnetic resonance (NMR) spectrometry (2

More information

Chemistry 307 Chapter 10 Nuclear Magnetic Resonance

Chemistry 307 Chapter 10 Nuclear Magnetic Resonance Chemistry 307 Chapter 10 Nuclear Magnetic Resonance Nuclear magnetic resonance (NMR) spectroscopy is one of three spectroscopic techniques that are useful tools for determining the structures of organic

More information

NMR - Basic principles

NMR - Basic principles NMR - Basic principles Subatomic particles like electrons, protons and neutrons are associated with spin - a fundamental property like charge or mass. In the case of nuclei with even number of protons

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

Using Nuclear Magnetic Resonance Spectroscopy to Identify an Unknown Compound prepared by Joseph W. LeFevre, SUNY Oswego

Using Nuclear Magnetic Resonance Spectroscopy to Identify an Unknown Compound prepared by Joseph W. LeFevre, SUNY Oswego m o d u l a r l a b o r a t o r y p r o g r a m i n c h e m i s t r y publisher:. A. Neidig organic editor: Joe Jeffers TE 711 Using Nuclear Magnetic Resonance Spectroscopy to Identify an Unknown ompound

More information

NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY PRINCIPLE AND APPLICATION IN STRUCTURE ELUCIDATION Professor S. SANKARARAMAN Department of Chemistry Indian Institute of Technology Madras Chennai 600 036 sanka@iitm.ac.in

More information

Molecular spectroscopy III: Nuclear Magnetic Resonance (NMR)

Molecular spectroscopy III: Nuclear Magnetic Resonance (NMR) Molecular spectroscopy III: Nuclear Magnetic Resonance (NMR) Nuclear magnetic resonance (NMR) is a physical phenomenon in which magnetic nuclei in a magnetic field absorb electromagnetic radiation at a

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

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

Shielding vs. Deshielding:

Shielding vs. Deshielding: Shielding vs. Deshielding: Pre-tutorial: Things we need to know before we start the topic: What does the NMR Chemical shift do? The chemical shift is telling us the strength of the magnetic field that

More information

The Hydrogen Atom Is a Magnet. http://www.seed.slb.com/en/scictr/watch/gashydrates/detecting.htm

The Hydrogen Atom Is a Magnet. http://www.seed.slb.com/en/scictr/watch/gashydrates/detecting.htm The Hydrogen Atom Is a Magnet Nuclear Magnetic Resonance Spectroscopy (NMR) Proton NMR A hydrogen nucleus can be viewed as a proton, which can be viewed as a spinning charge. As with any spinning charge,

More information

Structure Determination by NMR

Structure Determination by NMR Structure Determination by NMR * Introduction to NMR * 2D NMR, resonance assignments J Correlated Based Experiments * COSY - Correlated Spectroscopy * NOESY - Nuclear Overhauser Effect Spectroscopy * HETCOR

More information

Introduction to NMR Part 1. Revised 2/19/07 Anne M. Gorham

Introduction to NMR Part 1. Revised 2/19/07 Anne M. Gorham Introduction to NMR Part 1 Revised 2/19/07 Anne M. Gorham What is an NMR? Niobium-tin-copper clad coil wound like a spool of thread. The current runs through this coil, creating the magnetic field. This

More information

NMR Spectroscopy of Aromatic Compounds (#1e)

NMR Spectroscopy of Aromatic Compounds (#1e) NMR Spectroscopy of Aromatic Compounds (#1e) 1 H NMR Spectroscopy of Aromatic Compounds Erich Hückel s study of aromaticity in the 1930s produced a set of rules for determining whether a compound is aromatic.

More information

Signal Manipulation. time domain NMR signal in MHz range is converted to khz (audio) range by mixing with the reference ( carrier ) frequency

Signal Manipulation. time domain NMR signal in MHz range is converted to khz (audio) range by mixing with the reference ( carrier ) frequency NMR Spectroscopy: 3 Signal Manipulation time domain NMR signal in MHz range is converted to khz (audio) range by mixing with the reference ( carrier ) frequency Ref in (MHz) mixer Signal in (MHz) Signal

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

Nuclear Magnetic Resonance Spectroscopy

Nuclear Magnetic Resonance Spectroscopy Chapter 8 Nuclear Magnetic Resonance Spectroscopy http://www.yteach.co.uk/page.php/resources/view_all?id=nuclear_magnetic _resonance_nmr_spectroscopy_spin_spectrometer_spectrum_proton_t_pag e_5&from=search

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

Biophysical Chemistry: NMR Spectroscopy

Biophysical Chemistry: NMR Spectroscopy General Principle The Chemical Shift Vrije Universiteit Brussel 28th October 2011 General Principle Outline 1 General Principle Influence of Electron Clouds 2 3 Outline General Principle Influence of Electron

More information

Nuclear Magnetic Resonance Spectroscopy (NMR)

Nuclear Magnetic Resonance Spectroscopy (NMR) Nuclear Magnetic Resonance Spectroscopy (NMR) NMR is a spectroscopic technique which relies on the magnetic properties of the atomic nucleus. When placed in a strong magnetic field, certain nuclei resonate

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

NMR Spectroscopy. B = B o - B e ν o = γb/2π

NMR Spectroscopy. B = B o - B e ν o = γb/2π NMR Spectroscopy hem 345 Univ. Wisconsin, Madison hemical Shifts hemical shifts have their origin in the circulation of electrons induced by the magnetic field, which reduces the actual field at the nucleus.

More information

Instrumental Lab. Nuclear Magnetic Resonance. Dr Alex J. Roche

Instrumental Lab. Nuclear Magnetic Resonance. Dr Alex J. Roche Instrumental Lab Nuclear Magnetic Resonance Dr Alex J. Roche 1 Nuclear Magnetic Resonance (NMR) Spectroscopy NMR is the most powerful analytical tool currently available to an organic chemist. NMR allows

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

Nuclear Magnetic Resonance (NMR) Wade Textbook

Nuclear Magnetic Resonance (NMR) Wade Textbook Nuclear Magnetic Resonance (NMR) Wade Textbook Background Is a nondestructive structural analysis technique Has the same theoretical basis as magnetic resonance imaging (MRI) Referring to MRI as nuclear

More information

Nuclear Magnetic Resonance (NMR) Spectroscopy cont... Recommended Reading:

Nuclear Magnetic Resonance (NMR) Spectroscopy cont... Recommended Reading: Applied Spectroscopy Nuclear Magnetic Resonance (NMR) Spectroscopy cont... Recommended Reading: Banwell and McCash Chapter 7 Skoog, Holler Nieman Chapter 19 Atkins, Chapter 18 Relaxation processes We need

More information

NMR for Organic Chemistry III

NMR for Organic Chemistry III NMR for rganic Chemistry III Lecture 1 Lecture 2 Lecture 3 Lecture 4 Recap of Key Themes from NMR II + Problems CSY + Problems HSQC + Problems HMBC and Solving Structures + Problems 1 1. Practical Aspects

More information

Organic Spectroscopy: a Primer

Organic Spectroscopy: a Primer EM 03 rganic Spectroscopy: a Primer INDEX A. Introduction B. Infrared (IR) Spectroscopy 3. Proton Nuclear Magnetic Resonance ( NMR) Spectroscopy A. Introduction The problem of determining the structure

More information

NMR Guidelines for ACS Journals

NMR Guidelines for ACS Journals NMR Guidelines for ACS Journals Updated December 2013 1. NMR Text (Experimental Section) 1.1 The compound must be clearly identified, for example in a header at the beginning of a) the synthetic procedure

More information

INTERPRETING 2D NMR SPECTRA 1

INTERPRETING 2D NMR SPECTRA 1 INTERPRETING D NMR SPETRA 1 ow To Read SY Spectra -Nitropropane: To see what type of information a SY spectrum may provide. we shall consider several examples of increasing complexity. The first is the

More information

2D NMR Spectroscopy. Lecture 3

2D NMR Spectroscopy. Lecture 3 2D NMR Spectroscopy Lecture 3 hemical shifts The chemical environment affects the magnetic field of nuclei. B eff = B o - B loc B eff = B o ( - σ ) σ is the magnetic shielding of the nucleus. Factors that

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

Introduction to Nuclear Magnetic Resonance Spectroscopy

Introduction to Nuclear Magnetic Resonance Spectroscopy Introduction to Nuclear Magnetic Resonance Spectroscopy Dr. Dean L. Olson, NMR Lab Director School of Chemical Sciences University of Illinois Called figures, equations, and tables are from Principles

More information

20. NMR Spectroscopy and Magnetic Properties

20. NMR Spectroscopy and Magnetic Properties 20. NMR Spectroscopy and Magnetic Properties Nuclear Magnetic Resonance (NMR) Spectroscopy is a technique used largely by organic, inorganic, and biological chemists to determine a variety of physical

More information

Determination of Equilibrium Constants using NMR Spectrscopy

Determination of Equilibrium Constants using NMR Spectrscopy CHEM 331L Physical Chemistry Laboratory Revision 2.0 Determination of Equilibrium Constants using NMR Spectrscopy In this laboratory exercise we will measure the Equilibrium Constant K c for the keto-enol

More information

NMR 13 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 1H NMR

NMR 13 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 1H NMR A P T E R 13 Spectroscopy A P T E R U T L I N E 13.1 Principles of Molecular Spectroscopy: Electromagnetic Radiation......... 518 13.2 Principles of Molecular Spectroscopy: Quantized Energy States..........

More information

Infrared Spectroscopy 紅 外 線 光 譜 儀

Infrared Spectroscopy 紅 外 線 光 譜 儀 Infrared Spectroscopy 紅 外 線 光 譜 儀 Introduction Spectroscopy is an analytical technique which helps determine structure. It destroys little or no sample (nondestructive method). The amount of light absorbed

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

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

NMR Nuclear Magnetic Resonance

NMR Nuclear Magnetic Resonance NMR Nuclear Magnetic Resonance Nuclear magnetic resonance (NMR) is an effect whereby magnetic nuclei in a magnetic field absorb and re-emit electromagnetic (EM) energy. This energy is at a specific resonance

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

If replacement of each of two hydrogens by some group leads to enantiomers, those hydrogens are enantiotopic

If replacement of each of two hydrogens by some group leads to enantiomers, those hydrogens are enantiotopic Homotopic Hydrogens Hydrogens are chemically equivalent or homotopic if replacing each one in turn by the same group would lead to an identical compound If replacement of each of two hydrogens by some

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

Interpretation of 1 H spectra

Interpretation of 1 H spectra Interpretation of 1 spectra So far we have talked about different NMR techniques and pulse sequences, but we haven t focused seriously on how to analyze the data that we obtain from these experiments.

More information

CHARACTERISTIC FUNCTIONAL-GROUP NMR ABSORPTIONS 13.7. A. NMR Spectra of Alkenes 612 CHAPTER 13 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

CHARACTERISTIC FUNCTIONAL-GROUP NMR ABSORPTIONS 13.7. A. NMR Spectra of Alkenes 612 CHAPTER 13 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 612 APTER 13 NULEAR MAGNETI RESONANE SPETROSOPY PROBLEMS 13.22 The d 1.2 1.5 region of the 300-Mz NMR spectrum of 1-chlorohexane, given in Fig. 13.12, is complex and not first-order. Assuming you could

More information

Proton NMR. One Dimensional H-NMR. Cl S. Common types of NMR experiments: 1-H NMR

Proton NMR. One Dimensional H-NMR. Cl S. Common types of NMR experiments: 1-H NMR Common types of NMR experiments: 1- NMR Proton NMR ne Dimensional -NMR a. Experiment igh field proton NMR (400Mz). single-pulse experiment. b. Spectral nterpretation i. Number of multiplets gives the different

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

School of Chemistry, Food and Pharmacy

School of Chemistry, Food and Pharmacy School of Chemistry, Food and Pharmacy Interpretation of Experiments from ICONNMR By using some or all of the seven experiments ( 1 H, 13 C, DEPT, HSQC, HMBC, COSY and NOESY) which are routinely available

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

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

TWO DIMENSIONAL CORRELATED NMR SPECTROSCOPY

TWO DIMENSIONAL CORRELATED NMR SPECTROSCOPY TWO DIMENSIONAL 2D-NMR TWO DIMENSIONAL CORRELATED NMR SPECTROSCOPY Two-dimensional J-resolved spectrum: Frequencies plotted on one axis, coupling constants on the other. Two-dimensional shift correlated

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

Determination of Equilibrium Constants using NMR Spectrscopy

Determination of Equilibrium Constants using NMR Spectrscopy CHEM 331L Physical Chemistry Laboratory Revision 1.0 Determination of Equilibrium Constants using NMR Spectrscopy In this laboratory exercise we will measure a chemical equilibrium constant using key proton

More information

Introduction to NMR Spectroscopy and Imaging Assignment for Chapter 02: Chemical shift and J Coupling

Introduction to NMR Spectroscopy and Imaging Assignment for Chapter 02: Chemical shift and J Coupling Introduction to NMR Spectroscopy and Imaging Assignment for Chapter 02: Chemical shift and J Coupling 0. Choose the correct one(s) from the following statements or explain briefly your supporting reason

More information

10. Geometry Hybridization Unhybridized p atomic orbitals

10. Geometry Hybridization Unhybridized p atomic orbitals APTER 14 VALET BDIG: RBITALS The Localized Electron Model and ybrid rbitals 9. The valence orbitals of the nonmetals are the s and p orbitals. The lobes of the p orbitals are 90E and 180E apart from each

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

Introduction to 1D and 2D NMR Spectroscopy (1) Basics

Introduction to 1D and 2D NMR Spectroscopy (1) Basics Introduction to 1D and 2D NMR Spectroscopy (1) Basics Lecturer: Weiguo Hu A328 Conte (7-1428) weiguoh@polysci.umass.edu October 2009 1 Content At a Glance Introduction to 1D and 2D NMR Spectroscopy Experimentation

More information