Biophysical Chemistry: NMR Spectroscopy

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Biophysical Chemistry: NMR Spectroscopy"

Transcription

1 General Principle The Chemical Shift Vrije Universiteit Brussel 28th October 2011

2 General Principle Outline 1 General Principle Influence of Electron Clouds 2 3

3 Outline General Principle Influence of Electron Clouds 1 General Principle Influence of Electron Clouds 2 3

4 Reminder: Energy Levels of a Spin-1/2

5 The Induced Field General Principle Influence of Electron Clouds B 0 B 0 B 0 B 0 B 0 B = B ind = σb 0 B' B' B' B' B' B local = B 0 + B ind = (1 σ)b 0 ω = γb 0 (1 σ) The external magnetic field induces currents in the electron cloud around the nucleus. These currents in turn generate a magnetic field, proportionate to the external field and slightly weakening or enhancing it at the site of the nucleus.

6 General Principle Influence of Electron Clouds The Chemical Shift The frequency difference is expressed as a relative difference with respect to a standard, eliminating the influence of the external field and resulting in a characteristic chemical shift value (independent of B 0 ): δ = ν ν ref = γb 0(1 σ) γb 0 (1 σ ref ) = σ ref σ ν ref γb 0 (1 σ ref ) 1 σ ref Since the numeric value of δ is in practice never more than 10 4, it is generally expressed in terms of "parts per million" (ppm). Tetramethyl silane (TMS) and 2,2-dimethyl 2-silapentane 5-sulphonic acid (DSS) are the most commonly used reference compounds for 1 H and 13 C chemical shifts.

7 Shielding and Deshielding (1)

8 Shielding and Deshielding (2)

9 Shielding and Deshielding (3)

10 Shielding and Deshielding (4)

11 A Numeric Example

12 Outline General Principle 1 General Principle Influence of Electron Clouds 2 3

13 General Description General Principle The shielding factor σ can in general be divided into a diamagnetic contribution (resulting from electron currents within molecular orbitals), and a paramagnetic contribution (due to movements of electrons between different orbitals): with σ = σ dia + σ para σ dia > 0; σ para < 0 Both terms can be further subdivided into components that can be rationalised in terms of molecular structure with different degrees of success.

14 General Principle Molecular Symmetry In symmetric molecules many (or all) hydrogen atoms will have the same electronic environment, and thus end up with the same chemical shift. Simple symmetry arguments can sometimes go a long way in the analysis of spectra.

15 General Principle Quantitative Integration of Intensities In simple cases the relative area under each peak can be used to "count" the atoms in each distinct chemical environment.

16 Outline General Principle 1 General Principle Influence of Electron Clouds 2 3

17 In some cases, such as the methyl halides (below) and the substituted aromatics (right), the observed chemical shifts can be explained using elementary chemical principles.

18 Neighbouring Groups This schematic molecule has an elongated cloud of electrons (blue), and two sites A and B at different fixed positions relative to this cloud. µ // and µ are the externally induced dipoles in the electron cloud for the two orientations shown, and will in general both be aligned with the external field B 0, but have different magnitudes.

19 General Principle Effect of a Triple Bond (µ > 0 (mainly a paramagnetic effect) and µ // 0, which means µ // µ < 0)

20 General Principle Effct of an Aromatic Ring (µ 0, while µ // < 0 (mainly a diamagnetic effect), which again means µ // µ < 0)

21 General Principle Effect of Hydrogen Bonds Hydrogen bonds can lead to strong deshielding of the affected proton.

22 Protein Spectra General Principle Although the hundreds or thousands of protons in a protein molecule all have unique environments and hence chemical shifts, the limited range means that the spectrum is still very crowded, even in ideal conditions: A few signals can be studied in isolation, but the vast majority is lost in a forest of overlapping signals.

23 General Principle Functional Groups in Proteins The difference in the electronic environment between the protonated and unprotonated forms can be used to determine the pk a of individual histidine side chains: δ avg = δ HA +[HA+ ] + δ A [A] [HA + ] + [A]

24 Special Cases General Principle Atoms and radical with unpaired electrons give rise to strong paramagnetic effects, leading to extreme negative chemical shifts. (The gyromagnetic ratio of the electron is 660 times larger than even that of the proton.)

25 General Principle (1) The resonance frequency of an isolated nucleus in an external magnetic field is determined only by the gyromagnetic ratio of the nucleus and the strength of the field. In an atom or molecule, however, the nucleus is surrounded by a cloud of electrons that proportionately modifies the effective magnetic field at the site of the nucleus. Because different nuclei of the same type can occupy different chemical (and therefore electronic) environments, they can resonate at slightly different frequencies and be distinguished. The most convenient quantitative measure for this effect of the local chemical environment is the chemical shift δ, which is characteristic of a given chemical environment and independent of the external field strength.

26 General Principle (2) With a suffciently detailed description of the behaviour of the electrons in a molecule, chemical shifts can in principle be calculated. Even when a detailed interpretation is not feasible, chemical shifts are still extremely valuable for the identification of atoms in molecules and as markers for processes.

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

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 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

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

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

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

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

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

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

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

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

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 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

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

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

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

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

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

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

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

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

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

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

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 9 - Covalent Bonding: Orbitals

Chapter 9 - Covalent Bonding: Orbitals Chapter 9 - Covalent Bonding: Orbitals 9.1 Hybridization and the Localized Electron Model A. Hybridization 1. The mixing of two or more atomic orbitals of similar energies on the same atom to produce new

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

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

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

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

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

Nuclear Magnetic Resonance Spectroscopy

Nuclear Magnetic Resonance Spectroscopy Most spinning nuclei behave like magnets. Nuclear Magnetic Resonance Spectroscopy asics owever, as opposed to the behavior of a classical magnet the nuclear spin magnetic moment does not always align with

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

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

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

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

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

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

The Experiment Some nuclei have nuclear magnetic moments; just as importantly, some do not

The Experiment Some nuclei have nuclear magnetic moments; just as importantly, some do not Chemistry 2600 Lecture Notes Chapter 15 Nuclear Magnetic Resonance Spectroscopy Page 1 of 23 Structure Determination in Organic Chemistry: NMR Spectroscopy Three main techniques are used to determine the

More information

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

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

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

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

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

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

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

Chemical shifts. Aromatic bonds/aromatics Acetal Methylene (CH2 R1R2) ~1.3. Methoxy Metal hydride 5 to 20

Chemical shifts. Aromatic bonds/aromatics Acetal Methylene (CH2 R1R2) ~1.3. Methoxy Metal hydride 5 to 20 Chemical shifts Discovered in 1950 by Proctor and Yu based on solution 14 N NMR studies of N4NO3 1 chemical shifts Empirical correlations between chemical shifts and structure Typical 1 chemical shift

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

NMR Spectroscopy. Principles and Applications to Proteins. Patrik Lundström

NMR Spectroscopy. Principles and Applications to Proteins. Patrik Lundström NMR Spectroscopy Principles and Applications to Proteins Patrik Lundström 2013 1 Preface This text is intended as a complement to the book NMR spectroscopy by P.J. Hore used for the course Biomolecular

More information

Valence shell electrons repel each other Valence shell electrons are arranged geometrically around the central atom to

Valence shell electrons repel each other Valence shell electrons are arranged geometrically around the central atom to Molecular Geometry (Valence Shell Electron Pair Repulsion -VSEPR) & Hybridization of Atomic Orbitals (Valance Bond Theory) Chapter 10 Valence Shell Electron Pair Repulsion (VSEPR) Valence shell electrons

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

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

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

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

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

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

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

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

By submitting this essay, I attest that it is my own work, completed in accordance with University regulations. Andrew Yang

By submitting this essay, I attest that it is my own work, completed in accordance with University regulations. Andrew Yang CHEM 251L: Inorganic Chemistry Laboratory Professor Jonathan Parr By submitting this essay, I attest that it is my own work, completed in accordance with University regulations. Andrew Yang An Introduction

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

Christ Church 3 rd Year: Magnetic Resonance. Reading. Topics

Christ Church 3 rd Year: Magnetic Resonance. Reading. Topics Christ Church 3 rd Year: Magnetic Resonance Reading The following sources are recommended for this tutorial: Nuclear Magnetic Resonance by P. J. Hore (Oxford Chemistry Primers). This text contains the

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

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

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

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

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

Introduction to Nuclear Magnetic Resonance (NMR) And. NMR Metabolomics

Introduction to Nuclear Magnetic Resonance (NMR) And. NMR Metabolomics Introduction to Nuclear Magnetic Resonance (NMR) And NMR Metabolomics Acknowledgment: Some slides from talks by Natalia Serkova, Wimal Pathmasiri, and from many internet sources (e.g., U of Oxford, Florida

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

Nov 26 Hybrid orbitals; MO theory Ch. 12

Nov 26 Hybrid orbitals; MO theory Ch. 12 What s coming up??? Oct 25 The atmosphere, part 1 Ch. 8 Oct 27 Midterm No lecture Oct 29 The atmosphere, part 2 Ch. 8 Nov 1 Light, blackbodies, Bohr Ch. 9 Nov 3,5 Postulates of QM, p-in-a-box Ch. 9 Nov

More information

Suggested solutions for Chapter 21

Suggested solutions for Chapter 21 s for Chapter 21 21 PRBLEM 1 All you have to do is to spot the aromatic rings in these compounds. t may not be as easy as you think and you should give some reasons for questionable decisions. C 2 colchicine:

More information

1 H NMR and 13 C NMR spectra interpretation

1 H NMR and 13 C NMR spectra interpretation 1 NMR and 13 C NMR spectra interpretation Ewa Dudziak Introduction Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful method for organic molecule structure determination. Moreover, NMR allows

More information

CHAPTER NOTES CHAPTER 16. Covalent Bonding

CHAPTER NOTES CHAPTER 16. Covalent Bonding CHAPTER NOTES CHAPTER 16 Covalent Bonding Goals : To gain an understanding of : NOTES: 1. Valence electron and electron dot notation. 2. Stable electron configurations. 3. Covalent bonding. 4. Polarity

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

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

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

Use the Force! Noncovalent Molecular Forces

Use the Force! Noncovalent Molecular Forces Use the Force! Noncovalent Molecular Forces Not quite the type of Force we re talking about Before we talk about noncovalent molecular forces, let s talk very briefly about covalent bonds. The Illustrated

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 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

Chemical bonds between atoms involve electrons.

Chemical bonds between atoms involve electrons. Chapter 6, Section 2 Key Concept: Chemical bonds hold compounds together. BEFORE, you learned Elements combine to form compounds Electrons are located in a cloud around the nucleus Atoms can lose or gain

More information

A splitting of a signal means that we have more energies involved in the transition of a certain nuclei. So why do we have more energies?

A splitting of a signal means that we have more energies involved in the transition of a certain nuclei. So why do we have more energies? Spin-spin coupling analysis The last parameter that we will discuss concerning the interpretation of NMR spectra is the 1 H spin-spin coupling. Couplings are perhaps the most important parameter in NMR,

More information

Chemical Bonds. a. Duet Rule: 2 electrons needed to satisfy valence shell. i. What follows this rule? Hydrogen and Helium

Chemical Bonds. a. Duet Rule: 2 electrons needed to satisfy valence shell. i. What follows this rule? Hydrogen and Helium Chemical Bonds 1. Important points about Lewis Dot: a. Duet Rule: 2 electrons needed to satisfy valence shell. i. What follows this rule? Hydrogen and Helium b. Octet Rule: 8 electrons needed to satisfy

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

Effect of unshared pairs on molecular geometry

Effect of unshared pairs on molecular geometry Chapter 7 covalent bonding Introduction Lewis dot structures are misleading, for example, could easily represent that the electrons are in a fixed position between the 2 nuclei. The more correct designation

More information

The Unified Scale for Referencing in NMR: New IUPAC Recommendations revised (cgf): 26 July 2010

The Unified Scale for Referencing in NMR: New IUPAC Recommendations revised (cgf): 26 July 2010 The Unified Scale for Referencing in NMR: New IUPAC Recommendations revised (cgf): 26 July 2010 In 2001, IUPAC set new definitions and standards for NMR referencing, 1 and updated these in 2008. 2 A significant

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

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

Chapter 1 Structure and Bonding. Modified by Dr. Daniela Radu

Chapter 1 Structure and Bonding. Modified by Dr. Daniela Radu John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 1 Structure and Bonding Modified by Dr. Daniela Radu What is Organic Chemistry? Living things are made of organic chemicals Proteins that make

More information

Illustrating Bonds - Lewis Dot Structures

Illustrating Bonds - Lewis Dot Structures Illustrating Bonds - Lewis Dot Structures Lewis Dot structures are also known as electron dot diagrams These diagrams illustrate valence electrons and subsequent bonding A line shows each shared electron

More information

Counting Pi Electrons and Electrons Involved in Aromaticity

Counting Pi Electrons and Electrons Involved in Aromaticity Counting Pi Electrons and Electrons Involved in Aromaticity How to find atoms with p orbitals: When looking at a molecule and deciding how many lone pairs are in p orbitals, it is first important to decide

More information

NMR SPECTROSCOPY. Basic Principles, Concepts, and Applications in Chemistry. Harald Günther University of Siegen, Siegen, Germany.

NMR SPECTROSCOPY. Basic Principles, Concepts, and Applications in Chemistry. Harald Günther University of Siegen, Siegen, Germany. NMR SPECTROSCOPY Basic Principles, Concepts, and Applications in Chemistry Harald Günther University of Siegen, Siegen, Germany Second Edition Translated by Harald Günther JOHN WILEY & SONS Chichester

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

Name: Chemistry 114 First Hour Exam

Name: Chemistry 114 First Hour Exam Remember- Show all work for partial credit Name: Chemistry 114 First Hour Exam 1. (15 points) Hot and spicy food contain molecules that stimulate pain detecting nerve endings piperine (below) is one such

More information

1 Introduction to NMR Spectroscopy

1 Introduction to NMR Spectroscopy Introduction to NMR Spectroscopy Tremendous progress has been made in NMR spectroscopy with the introduction of multidimensional NMR spectroscopy and pulse Fourier transform NMR spectroscopy. For a deeper

More information

SAM Teachers Guide Chemical Bonds

SAM Teachers Guide Chemical Bonds SAM Teachers Guide Chemical Bonds Overview Students discover that the type of bond formed ionic, non polar covalent, or polar covalent depends on the electronegativity of the two atoms that are bonded

More information

Laboratory 11: Molecular Compounds and Lewis Structures

Laboratory 11: Molecular Compounds and Lewis Structures Introduction Laboratory 11: Molecular Compounds and Lewis Structures Molecular compounds are formed by sharing electrons between non-metal atoms. A useful theory for understanding the formation of molecular

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 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

Tetramethylsilane (TMS) Trimethylsilyl d 4. -propionic acid (TMSP) Dioxane. O - Na + Dimethylfura n. Potassium Hydrogen Phthalate. Sodium Maleate CH 3

Tetramethylsilane (TMS) Trimethylsilyl d 4. -propionic acid (TMSP) Dioxane. O - Na + Dimethylfura n. Potassium Hydrogen Phthalate. Sodium Maleate CH 3 Practical Aspects of Quantitative NMR Experiments This discussion presumes that you already have an understanding of the basic theory of NMR. There are a number of issues that should be considered when

More information

Spectroscopy in Inorganic Chemistry (Theory)

Spectroscopy in Inorganic Chemistry (Theory) 1 Introduction Spectroscopy in Inorganic Chemistry (Theory) Spectroscopy is the study of the interaction of electromagnetic radiation with matter. Spectroscopy has many applications in the modern world,

More information

Valence Bond Theory - Description

Valence Bond Theory - Description Bonding and Molecular Structure - PART 2 - Valence Bond Theory and Hybridization 1. Understand and be able to describe the Valence Bond Theory description of covalent bond formation. 2. Understand and

More information

Lecture #7 (2D NMR) Utility of Resonance Assignments

Lecture #7 (2D NMR) Utility of Resonance Assignments Lecture #7 (2D NMR) Basics of multidimensional NMR (2D NMR) 2D NOESY, COSY and TOCSY 2/23/15 Utility of Resonance Assignments Resonance Assignments: Assignment of frequency positions of resonances (peaks)

More information