MOLECULAR SPECTROSCOPY AND PHOTOCHEMISTRY
|
|
- Crystal Patterson
- 5 years ago
- Views:
Transcription
1 20 CHAPTER MOLECULAR SPECTROSCOPY AND PHOTOCHEMISTRY 20.1 Introduction to Molecular Spectroscopy 20.2 Experimental Methods in Molecular Spectroscopy 20.3 Rotational and Vibrational Spectroscopy 20.4 Nuclear Magnetic Resonance Spectroscopy 20.5 Electronic Spectroscopy and Excited State Relaxation Processes 20.7 Photosynthesis 941 Fluorescence microscope image of the mouse cerebral cortex. Three different dyes were used to selectively image structural proteins called neurofilaments, a small protein called General GFAP Chemistry that a component II of intermediate filaments, and cellular 2 nuclei.
2 20.4 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 966 Measures the energies and intensities of transition between nuclear spin states of 1 H, 13 C, nuclei Degeneracy of these energies lifted with applied external magnetic field Transition between these levels corresponding to radio frequency region ( MHz) Resonance frequency observed for a particular nucleus gives information around the nucleus Structure of the molecule Magnetic resonance imaging (MRI) technique in medicine Electron (spin 1/2) Magnitude of the electron spin angular momentum, s: s s( s1) ( h/ 2 ) Projection of the electron spin angular momentum, s, along the laboratory z-axis: s m, ( m ) z s s m s (spin "up", ), m (spin "down", ) s 2
3 967 Nuclear spin Magnitude of the nuclear spin angular momentum, I I I( I 1) Projection of the nuclear spin angular momentum, I, along the laboratory z-axis: I m, ( m ) z I I 1 2 Spin 1/2 nuclei: 1 H, 13 C, 15 N, 19 F, 29 Si, and 31 P Spin 0 nuclei: 12 C, 16 O Magnetic dipole moment of a nucleus i vs. nuclear spin I g I i i N i 967 N 27 1 eh / 4mP J T : Nuclear magneton g i : nuclear g-factor of nucleus i ( 1 H: g = 5.586, 13 C: g =1.405) Energy, E, of a magnetic dipole moment,, in an external magnetic field, B 0, oriented along the z-axis E B g I B ( g I B ) m, where m 1 z 0 N z 0 N z 0 I I 2 E g B h Zeeman effect N N 0 0
4 967 Nobel Prize in Physics (1902) "in recognition of the extraordinary service they rendered by their researches into the influence of magnetism upon radiation phenomena" Hendrik A. Lorentz (DEU, ) Pieter Zeeman (DEU, ) NMR Spectrometer Sample in the tube (5 mm diameter) in a magnetic field Radio frequency input radiation by the 1 st set of coil Radiofrequency output radiation by the 2 nd set of coil Setting the frequency and scanning the magnetic field until the sample comes into resonance. 968 Fig Schematic of an FT NMR spectrometer. 50
5 968 Fig (a) Energy level splitting diagram for a proton in an external magnetic field. The vertical line shows the absorption transition for a 7.05 T field. (b) Proton NMR spectrum obtained by scanning the magnetic field in a 300 MHz NMR spectrometer. Fourier transform NMR (FT-NMR) 969 (1) Excitation of spins in thermal equilibrium by a short burst of broad band radiofrequency radiation (2) Emit radiation as they return to thermal equilibrium (3) Transient decay of this emission is recorded (4) Transient is analyzed using a Fourier transform algorithm producing a spectrum showing resonance frequencies which differ due to shielding and spin-spin splitting.
6 Analogy with a struck piano string 969 Fig (a) A pure sine wave oscillating at 440 Hz (concert A) and its Fourier transform. (b) A struck piano string (concert E = 330 Hz), its transient decay and Fourier transform showing the relative intensities of the harmonics. Intensities of NMR spectra depend on the population difference between the spin states Fractional population difference: N / N 1exp( / k T) For NMR, N / N 1 exp( g B / k T) B N 0 B NMR spectrometers identified by proton resonance frequency. 969 Ex. 300 MHz instrument has 7.05 T (tesla) magnet.
7 Chemical Shift 970 Local magnetic field felt by a nucleus is slightly different from the external magnetic field B (1 ) B local 0 : shielding constant External magnetic field induces current that shields the nucleus Very sensitive to the nature of the bonds formed with neighbors Frequency shifts are very small ( is very small) 100 ~ 1000 Hz in a 300 MHz spectrometer Scale based on the difference between the resonance freq. s of the sample and the reference material, TMS (tetramethylsilane) Chemical shift, : s r 10 r (1 ) (1 ) 6 s : resonance freq. of sample r : resonance freq. of reference s r 6 6 or 10 ( r s) 10 (1 r ) 970 Fig H NMR spectrum of methyl acetate showing resonances from two different methyl groups, one attached to the carbonyl carbon atom and one attached to the oxygen atom of the ester group.
8 970 TMS protons are well shielded TMS proton resonances at very high frequencies upfield Other protons are less well shielded downfield Equivalent protons (CH 3 ) L (at = 2.0) vs. (CH 3 ) R (at = 3.6) When the methyl group is free to rotate Protons in (CH 3 ) R are deshielded compared with protons in (CH 3 ) L (Due to the high electronegativity of O) downfield Same heights of two peaks Same number of protons in each group 971 Fig Ranges of 1 H NMR chemical shifts for protons in different functional groups.
9 Spin-spin splitting Fine structure for a particular resonance due to the magnetic fields of neighboring nuclei multiplet structure 971 Fig The NMR spectrum of 1,1-dichloroethane showing a doublet of peaks due to the splitting of the methyl(ch 3 ) protons by the proton of the adjacent methane proton and a quartet of peaks due to the splitting of the methine proton by the adjacent methyl protons. 972 J ab : spin-spin splitting constant Fig Spin-spin coupling between a single proton H a and groups of one, two and three equivalent protons H b on the adjacent carbon atom.
10 EXAMPLE H spectrum of diethyl ketone, (C 2 H 5 ) 2 CO. 972 Combination of a triplet and a quartet is a characteristic of an ethyl group: ~ Triplet for methyl protons due to methylene protons ~ Quartet for methylene protons due to methyl protons 20.5 ELECTRONIC SPECTOSCOPY AND EXCITED STATE RELAXATION PROCESSES 973 Electronic spectroscopy Transitions between electronic states (UV or visible range) Electronic emission spectroscopy (fluorescence) ~ Study of dynamics of energy and electron transfer processes (femtosecond processes, 1 fs = s) Relaxation of excited electronic states by ~ Emission of fluorescence or phosphorescence ~ Dissipation of energy as heat by nonradiative processes
Chapter 13 Structure t Determination: Nuclear Magnetic Resonance Spectroscopy
John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 13 Structure t Determination: ti Nuclear Magnetic Resonance Spectroscopy Revisions by Dr. Daniel Holmes MSU Paul D. Adams University of Arkansas
More information16.1 Introduction to NMR Spectroscopy. Spectroscopy. Spectroscopy. Spectroscopy. Spectroscopy. Spectroscopy 4/11/2013
What is spectroscopy? NUCLEAR MAGNETIC RESONANCE (NMR) spectroscopy may be the most powerful method of gaining structural information about organic compounds. NMR involves an interaction between electromagnetic
More informationChapter 7. Nuclear Magnetic Resonance Spectroscopy
Chapter 7 Nuclear Magnetic Resonance Spectroscopy I. Introduction 1924, W. Pauli proposed that certain atomic nuclei have spin and magnetic moment and exposure to magnetic field would lead to energy level
More informationPrinciples of Molecular Spectroscopy: Electromagnetic Radiation and Molecular structure. Nuclear Magnetic Resonance (NMR)
Principles of Molecular Spectroscopy: Electromagnetic Radiation and Molecular structure Nuclear Magnetic Resonance (NMR) !E = h" Electromagnetic radiation is absorbed when the energy of photon corresponds
More informationQuímica Orgânica I. Nuclear Magnetic Resonance Spectroscopy (I) Ciências Farmacêuticas Bioquímica Química AFB QO I 2007/08 1 AFB QO I 2007/08 2
Química Orgânica I Ciências Farmacêuticas Bioquímica Química AFB QO I 2007/08 1 Nuclear Magnetic Resonance Spectroscopy (I) AFB QO I 2007/08 2 1 Adaptado de: Organic Chemistry, 6th Edition; L. G. Wade,
More informationStructure Determination: Nuclear Magnetic Resonance Spectroscopy
Structure Determination: Nuclear Magnetic Resonance Spectroscopy Why This Chapter? NMR is the most valuable spectroscopic technique used for structure determination More advanced NMR techniques are used
More informationExperiment 2 - NMR Spectroscopy
Experiment 2 - NMR Spectroscopy OBJECTIVE to understand the important role of nuclear magnetic resonance spectroscopy in the study of the structures of organic compounds to develop an understanding of
More informationChapter 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 information4) protons experience a net magnetic field strength that is smaller than the applied magnetic field.
1) Which of the following CANNOT be probed by an NMR spectrometer? See sect 15.1 Chapter 15: 1 A) nucleus with odd number of protons & odd number of neutrons B) nucleus with odd number of protons &even
More information4) protons experience a net magnetic field strength that is smaller than the applied magnetic field.
1) Which of the following CANNOT be probed by an spectrometer? See sect 15.1 Chapter 15: 1 A) nucleus with odd number of protons & odd number of neutrons B) nucleus with odd number of protons &even number
More informationCHEM Chapter 13. Nuclear Magnetic Spectroscopy (Homework) W
CHEM 2423. Chapter 13. Nuclear Magnetic Spectroscopy (Homework) W Short Answer 1. For a nucleus to exhibit the nuclear magnetic resonance phenomenon, it must be magnetic. Magnetic nuclei include: a. all
More informationWilliam H. Brown & Christopher S. Foote
Requests for permission to make copies of any part of the work should be mailed to:permissions Department, Harcourt Brace & Company, 6277 Sea Harbor Drive, Orlando, Florida 32887-6777 William H. Brown
More informationNuclear Magnetic Resonance Spectroscopy: Tools for Structure Determination
Nuclear Magnetic Resonance Spectroscopy: Tools for Structure Determination Chung-Ming Sun Department of Applied Chemistry National Chiao Tung University Hualien 300, Taiwan Introduction NMR (Nuclear Magnetic
More informationThe Use of NMR Spectroscopy
Spektroskopi Molekul Organik (SMO): Nuclear Magnetic Resonance (NMR) Spectroscopy All is adopted from McMurry s Organic Chemistry The Use of NMR Spectroscopy Used to determine relative location of atoms
More informationTuesday, January 13, NMR Spectroscopy
NMR Spectroscopy 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
More informationNuclear Magnetic Resonance Spectroscopy
Chapter 5 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 information16.1 Introduction to NMR. Spectroscopy
16.1 Introduction to NMR What is spectroscopy? Spectroscopy NUCLEAR MAGNETIC RESNANCE (NMR) spectroscopy may be the most powerful method of gaining structural information about organic compounds. NMR involves
More information11. Proton NMR (text , 12.11, 12.12)
2009, Department of Chemistry, The University of Western Ontario 11.1 11. Proton NMR (text 12.6 12.9, 12.11, 12.12) A. Proton Signals Like 13 C, 1 H atoms have spins of ±½, and when they are placed in
More informationChapter 13 Spectroscopy
hapter 13 Spectroscopy Infrared spectroscopy Ultraviolet-Visible spectroscopy Nuclear magnetic resonance spectroscopy Mass Spectrometry 13.1 Principles of Molecular Spectroscopy: Electromagnetic Radiation
More informationLecture Notes Chem 51A S. King
Lecture Notes hem 51A S. King hapter 14 Nuclear Magnetic Resonance Spectroscopy Nuclear Magnetic Resonance (NMR) spectroscopy uses energy in the radiowave portion of the electromagnetic spectrum. The nuclei
More informationNMRis the most valuable spectroscopic technique for organic chemists because it maps the carbon-hydrogen framework of a molecule.
Chapter 13: Nuclear magnetic resonance spectroscopy NMRis the most valuable spectroscopic technique for organic chemists because it maps the carbon-hydrogen framework of a molecule. 13.2 The nature of
More informationChem 325 NMR Intro. The Electromagnetic Spectrum. Physical properties, chemical properties, formulas Shedding real light on molecular structure:
Physical properties, chemical properties, formulas Shedding real light on molecular structure: Wavelength Frequency ν Wavelength λ Frequency ν Velocity c = 2.998 10 8 m s -1 The Electromagnetic Spectrum
More informationNMR Spectroscopy. for 1 st B.Tech INTRODUCTION Lecture -1 Indian Institute of Technology, Dhanbad
NMR Spectroscopy for 1 st B.Tech Lecture -1 Indian Institute of Technology, Dhanbad by Dr. R P John & Dr. C. Halder INTRODUCTION Nucleus of any atom has protons and neutrons Both Proton and Neutron has
More informationThe resonance frequency of the H b protons is dependent upon the orientation of the H a protons with respect to the external magnetic field:
Spin-Spin Splitting in Alkanes The signal arising from a proton or set of protons is split into (N+1) lines by the presence of N adjacent nuclei Example 1: Bromoethane The resonance frequency of the H
More informationChapter 18: NMR Spectroscopy
The most important tool of the chemist for the determination of molecular structure is Nuclear Magnetic Resonance Spectroscopy, or NMR spectroscopy. NMR spectra are acquired on a special instrument called
More informationNuclear magnetic resonance spectroscopy
nuclear spin transitions O Nuclear magnetic resonance spectroscopy 1 H, 13 C, 2-dimensional which transitions? wavelength and intensity; ppm what happens if we change the environment of the nucleus? substituent
More informationChapter 16 Nuclear Magnetic Resonance Spectroscopy
hapter 16 Nuclear Magnetic Resonance Spectroscopy The Spinning Proton A spinning proton generates a magnetic field, resembling that of a small bar magnet. An odd number of protons in the nucleus creates
More information4) protons experience a net magnetic field strength that is smaller than the applied magnetic field.
1) Which of the following CANNOT be probed by an spectrometer? See sect 16.1 Chapter 16: 1 A) nucleus with odd number of protons & odd number of neutrons B) nucleus with odd number of protons &even number
More informationChapter 15 Lecture Outline
Organic Chemistry, First Edition Janice Gorzynski Smith University of Hawaii Chapter 5 Lecture Outline Introduction to NMR Two common types of NMR spectroscopy are used to characterize organic structure:
More informationChapter 13: Molecular Spectroscopy
Chapter 13: Molecular Spectroscopy Electromagnetic Radiation E = hν h = Planck s Constant (6.63 x 10-34 J. s) ν = frequency (s -1 ) c = νλ λ = wavelength (nm) Energy is proportional to frequency Spectrum
More informationNMR = Nuclear Magnetic Resonance
NMR = Nuclear Magnetic Resonance NMR spectroscopy is the most powerful technique available to organic chemists for determining molecular structures. Looks at nuclei with odd mass numbers or odd number
More informationNuclear Magnetic Resonance Spectroscopy
Nuclear Magnetic Resonance Spectroscopy Structural Elucidation Nuclear magnetic resonance spectroscopy is the name given to the technique which exploits the magnetic properties of nuclei and measures their
More informationNuclear Magnetic Resonance
Nuclear Magnetic Resonance PRINCIPLES OF NMR SPECTROSCOPY Contents Principles of nuclear magnetic resonance The nmr spectrometer Basic principles in nmr application NMR tools used to obtain information
More informationFluorescence and Nuclear Magnetic Resonance (NMR) Spectroscopy
Fluorescence and Nuclear Magnetic Resonance (NMR) Spectroscopy Murphy, B. (2017). Fluorescence and Nuclear Magnetic Resonance Spectroscopy: Lecture 3. Lecture presented at PHAR 423 Lecture in UIC College
More informationNuclear Magnetic Resonance (NMR)
Nuclear Magnetic Resonance (NMR) E E increases with increasing magnetic field strength Boltzmann distribution at thermal equilibrium: N (m=-1/2) /N (m=+1/2) = e ( E/kT) with E = γ(h/2π)b o NMR Physical
More informationChapter 14. Nuclear Magnetic Resonance Spectroscopy
Organic Chemistry, Second Edition Janice Gorzynski Smith University of Hawai i Chapter 14 Nuclear Magnetic Resonance Spectroscopy Prepared by Rabi Ann Musah State University of New York at Albany Copyright
More informationNuclear Magnetic Resonance (NMR) Spectroscopy Introduction:
Nuclear Magnetic Resonance (NMR) Spectroscopy Introduction: Nuclear magnetic resonance spectroscopy (NMR) is the most powerful tool available for organic structure determination. Like IR spectroscopy,
More informationNUCLEAR MAGNETIC RESONANCE AND INTRODUCTION TO MASS SPECTROMETRY
NUCLEAR MAGNETIC RESONANCE AND INTRODUCTION TO MASS SPECTROMETRY A STUDENT SHOULD BE ABLE TO: 1. Identify and explain the processes involved in proton ( 1 H) and carbon-13 ( 13 C) nuclear magnetic resonance
More informationNuclear Spin States. NMR Phenomenon. NMR Instrumentation. NMR Active Nuclei. Nuclear Magnetic Resonance
Nuclear Magnetic Resonance NMR Phenomenon µ A spinning charged particle generates a magnetic field. A nucleus with a spin angular momentum will generate a magnetic moment (!). E Nuclear Spin States aligned
More informationNUCLEAR MAGNETIC RESONANCE SPECTROSCOPY
NMR Spectroscopy 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 informationNMR Spectroscopy. Chapter 19
NMR Spectroscopy Chapter 19 Nuclear Magnetic Resonance spectroscopy is a powerful analytical technique used to characterize organic molecules by identifying carbon-hydrogen frameworks within molecules.
More informationPhysical Background Of Nuclear Magnetic Resonance Spectroscopy
Physical Background Of Nuclear Magnetic Resonance Spectroscopy Michael McClellan Spring 2009 Department of Physics and Physical Oceanography University of North Carolina Wilmington What is Spectroscopy?
More information4) protons experience a net magnetic field strength that is smaller than the applied magnetic field.
1) Which of the following CANNOT be probed by an spectrometer? See sect 16.1 Chapter 16: 1 A) nucleus with odd number of protons & odd number of neutrons B) nucleus with odd number of protons &even number
More informationInstrumental Chemical Analysis
L15 Page1 Instrumental Chemical Analysis Nuclear Magnetic Resonance Dr. Ahmad Najjar Philadelphia University Faculty of Pharmacy Department of Pharmaceutical Sciences 1 st semester, 2017/2018 Nuclear Magnetic
More information3.15 Nuclear Magnetic Resonance Spectroscopy, NMR
3.15 Nuclear Magnetic Resonance Spectroscopy, NMR What is Nuclear Magnetic Resonance - NMR Developed by chemists and physicists together it works by the interaction of magnetic properties of certain nuclei
More informationExperiment 11: NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY
Experiment 11: NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY Purpose: This is an exercise to introduce the use of nuclear magnetic resonance spectroscopy, in conjunction with infrared spectroscopy, to determine
More informationChapter 9. Nuclear Magnetic Resonance. Ch. 9-1
Chapter 9 Nuclear Magnetic Resonance Ch. 9-1 1. Introduction Classic methods for organic structure determination Boiling point Refractive index Solubility tests Functional group tests Derivative preparation
More informationSpectroscopy in Organic Chemistry. Types of Spectroscopy in Organic
Spectroscopy in Organic Chemistry Spectroscopy Spectrum dealing with light, or more specifically, radiation Scope to see Organic Spectroscopy therefore deals with examining how organic molecules interact
More information1. neopentyl benzene. 4 of 6
I. 1 H NMR spectroscopy A. Theory 1. The protons and neutrons in atomic nuclei spin, as does the nucleus itself 2. The circulation of nuclear charge can generate a nuclear magnetic moment, u, along the
More informationOAT Organic Chemistry - Problem Drill 19: NMR Spectroscopy and Mass Spectrometry
OAT Organic Chemistry - Problem Drill 19: NMR Spectroscopy and Mass Spectrometry Question No. 1 of 10 Question 1. Which statement concerning NMR spectroscopy is incorrect? Question #01 (A) Only nuclei
More informationChapter 13: Nuclear Magnetic Resonance (NMR) Spectroscopy direct observation of the H s and C s of a molecules
hapter 13: Nuclear Magnetic Resonance (NMR) Spectroscopy direct observation of the s and s of a molecules Nuclei are positively charged and spin on an axis; they create a tiny magnetic field + + Not all
More informationNMR Nuclear Magnetic Resonance Spectroscopy p. 83. a hydrogen nucleus (a proton) has a charge, spread over the surface
NMR Nuclear Magnetic Resonance Spectroscopy p. 83 a hydrogen nucleus (a proton) has a charge, spread over the surface a spinning charge produces a magnetic moment (a vector = direction + magnitude) along
More informationJanuary 30, 2018 Chemistry 328N
Lecture 4 Some More nmr January 30, 2018 Tricks for solving unknowns Review. Empirical formula is lowest common denominator ratio of atomic composition From Homework: unknown has an empirical formula of
More informationWith that first concept in mind, it is seen that a spinning nucleus creates a magnetic field, like a bar magnet
NMR SPECTROSCOPY This section will discuss the basics of NMR (nuclear magnetic resonance) spectroscopy. Most of the section will discuss mainly 1H or proton spectroscopy but the most popular nuclei in
More information4. NMR spectra. Interpreting NMR spectra. Low-resolution NMR spectra. There are two kinds: Low-resolution NMR spectra. High-resolution NMR spectra
1 Interpreting NMR spectra There are two kinds: Low-resolution NMR spectra High-resolution NMR spectra In both cases the horizontal scale is labelled in terms of chemical shift, δ, and increases from right
More informationChapter 14 Spectroscopy
hapter 14 Spectroscopy There are four major analytical techniques used for identifying the structure of organic molecules 1. Nuclear Magnetic Resonance or NMR is the single most important technique for
More informationModule 13: Chemical Shift and Its Measurement
Subject Chemistry Paper No and Title Module No and Title Module Tag Paper 12: Organic Spectroscopy CHE_P12_M13_e-Text TABLE OF CONTENTS 1. Learning Outcomes 2. Introduction 3. Shielding and deshielding
More informationIntroduction of Key Concepts of Nuclear Magnetic Resonance
I have not yet lost that sense of wonder, and delight, that this delicate motion should reside in all ordinary things around us, revealing itself only to those who looks for it. E. M. Purcell, Nobel Lecture.
More information7a. Structure Elucidation: IR and 13 C-NMR Spectroscopies (text , , 12.10)
2009, Department of Chemistry, The University of Western Ontario 7a.1 7a. Structure Elucidation: IR and 13 C-NMR Spectroscopies (text 11.1 11.5, 12.1 12.5, 12.10) A. Electromagnetic Radiation Energy is
More informationIntroduction 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 informationCHEM311 FALL 2005 Practice Exam #3
EM311 FALL 2005 Practice Exam #3 Instructions: This is a multiple choice / short answer practice exam. For the multiple-choice questions, there may be more than one correct answer. If so, then circle as
More informationCalculate a rate given a species concentration change.
Kinetics Define a rate for a given process. Change in concentration of a reagent with time. A rate is always positive, and is usually referred to with only magnitude (i.e. no sign) Reaction rates can be
More informationCHEM311 FALL 2005 Practice Exam #3
CHEM311 FALL 2005 Practice Exam #3 Instructions: This is a multiple choice / short answer practice exam. For the multiple-choice questions, there may be more than one correct answer. If so, then circle
More informationUNIT 12 NMR SPECTROSCOPY
UIT 12 MR SPECTROSCOPY MR Spectroscopy Structure 12.1 Introduction 12.2 Theory of MR Spectroscopy Types of uclei Magnetic Moment Quantisation Population of Energy Levels Larmor Precession Mechanism of
More informationSpectroscopy. Empirical Formula: Chemical Formula: Index of Hydrogen Deficiency (IHD)
Spectroscopy Empirical Formula: Chemical Formula: Index of Hydrogen Deficiency (IHD) A)From a structure: B)From a molecular formula, C c H h N n O o X x, Formula for saturated hydrocarbons: Subtract the
More informationNPTEL/IITM. Molecular Spectroscopy Lectures 1 & 2. Prof.K. Mangala Sunder Page 1 of 15. Topics. Part I : Introductory concepts Topics
Molecular Spectroscopy Lectures 1 & 2 Part I : Introductory concepts Topics Why spectroscopy? Introduction to electromagnetic radiation Interaction of radiation with matter What are spectra? Beer-Lambert
More informationBackground: In this chapter we will discuss the interaction of molecules with a magnetic field.
Chapter 4 NMR Background: In this chapter we will discuss the interaction of molecules with a magnetic field. * Nuclear Spin Angular Momenta - recall electrons & spin -- our spin functions are and which
More informationPaper 12: Organic Spectroscopy
Subject Chemistry Paper No and Title Module No and Title Module Tag Paper 12: Organic Spectroscopy 31: Combined problem on UV, IR, 1 H NMR, 13 C NMR and Mass - Part III CHE_P12_M31 TABLE OF CONTENTS 1.
More informationNuclear Magnetic Resonance Spectroscopy
Nuclear Magnetic Resonance Spectroscopy Features: Used to identify products of reactions Also gives information about chemical environment, connectivity and bonding of nuclei Requirements: Pure or mostly
More informationNuclear Magnetic Resonance H-NMR Part 1 Introduction to NMR, Instrumentation, Sample Prep, Chemical Shift. Dr. Sapna Gupta
Nuclear Magnetic Resonance H-NMR Part 1 Introduction to NMR, Instrumentation, Sample Prep, Chemical Shift Dr. Sapna Gupta Introduction NMR is the most powerful tool available for organic structure determination.
More informationOther problems to work: 3-Chloropentane (diastereotopic H s), 1- chloropentane.
Let s look at some specific examples. Dichloroacetaldehyde, l 2 HHO, has two inequivalent toms, H1 and H2. We expect to see two resonances, one at around δ 10.5 ppm and one around δ 5.5 ppm. (The H2 resonance
More informationIR, MS, UV, NMR SPECTROSCOPY
CHEMISTRY 318 IR, MS, UV, NMR SPECTROSCOPY PROBLEM SET All Sections CHEMISTRY 318 IR, MS, UV, NMR SPECTROSCOPY PROBLEM SET General Instructions for the 318 Spectroscopy Problem Set Consult the Lab Manual,
More informationNMR spectra of some simple molecules. Effect of spinning: averaging field inhomogeneity (nmr1.pdf pg 2)
NMR spectra of some simple molecules Effect of spinning: averaging field inhomogeneity (nmr1.pdf pg 2) N S H 0 H o Because the protons have a magnetic field associated with them, the field changes as across
More informationORGANIC - EGE 5E CH NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY
!! www.clutchprep.com CONCEPT: PURPOSE OF ANALYTICAL TECHNIQUES Classical Methods (Wet Chemistry): Chemists needed to run dozens of chemical reactions to determine the type of molecules in a compound.
More informationMagnetic Nuclei other than 1 H
Magnetic Nuclei other than 1 H 2 H (Deuterium): I = 1 H,D-Exchange might be used to simplify 1 H-NMR spectra since H-D couplings are generally small; - - - -O- - - -D 2 -O- triplet of triplets slightly
More information( ) electron gives S = 1/2 and L = l 1
Practice Modern Physics II, W018, Set 1 Question 1 Energy Level Diagram of Boron ion B + For neutral B, Z = 5 (A) Draw the fine-structure diagram of B + that includes all n = 3 states Label the states
More information- 1/2. = kb o = hνν + 1/2. B o increasing magnetic field strength. degenerate at B o = 0
NMR EXPERIMENT When magnetically active nuclei are placed into an external magnetic field, the magnetic fields align themselves with the external field into two orientations. During the experiment, electromagnetic
More informationBasic Concepts of NMR: Identification of the Isomers of C 4 O 2. by 1 H NMR Spectroscopy
Basic Concepts of NM: Identification of the Isomers of C H 8 O by H NM Spectroscopy Objectives NM spectroscopy is a powerful tool in determining the structure of compounds. Not only is it able to give
More informationIntroduction to NMR spectroscopy
Introduction to NMR spectroscopy Nuclei of isotopes which possess an odd number of protons, an odd number of neutrons, or both, have a nuclear spin quantum number, I, such that, I = 1/2n, where n is an
More informationCHEMISTRY Organic Chemistry Laboratory II Spring 2019 Lab #5: NMR Spectroscopy
Team Members: Unknown # CHEMISTRY 244 - Organic Chemistry Laboratory II Spring 2019 Lab #5: NMR Spectroscopy Purpose: You will learn how to predict the NMR data for organic molecules, organize this data
More informationHWeb27 ( ; )
HWeb27 (9.1-9.2; 9.12-9.18) 28.1. Which of the following cannot be determined about a compound by mass spectrometry? [a]. boiling point [b]. molecular formula [c]. presence of heavy isotopes (e.g., 2 H,
More informationNuclear Magnetic Resonance Spectroscopy
13 Nuclear Magnetic Resonance Spectroscopy Solutions to In-Text Problems 13.1 (b) Apply Eq. 13.2b with = 360 MHz. chemical shift in Hz = δ = (4.40)(360) = 1584 Hz 13.2 (b) Follow the same procedure used
More informationE35 SPECTROSCOPIC TECHNIQUES IN ORGANIC CHEMISTRY
E35 SPECTRSCPIC TECNIQUES IN RGANIC CEMISTRY Introductory Comments. These notes are designed to introduce you to the basic spectroscopic techniques which are used for the determination of the structure
More informationTo Do s. Answer Keys are available in CHB204H
To Do s Read Chapters 2, 3 & 4. Complete the end-of-chapter problems, 2-1, 2-2, 2-3 and 2-4 Complete the end-of-chapter problems, 3-1, 3-3, 3-4, 3-6 and 3-7 Complete the end-of-chapter problems, 4-1, 4-2,
More informationLecture 2 nmr Spectroscopy
Lecture 2 nmr Spectroscopy Pages 427 430 and Chapter 13 Molecular Spectroscopy Molecular spectroscopy: the study of the frequencies of electromagnetic radiation that are absorbed or emitted by substances
More informationChapter 13 Nuclear Magnetic Resonance Spectroscopy
William. Brown Christopher S. Foote Brent L. Iverson Eric Anslyn http://academic.cengage.com/chemistry/brown Chapter 13 Nuclear Magnetic Resonance Spectroscopy William. Brown Beloit College Two Nobel Prizes
More informationObjective 4. Determine (characterize) the structure of a compound using IR, NMR, MS.
Objective 4. Determine (characterize) the structure of a compound using IR, NMR, MS. Skills: Draw structure IR: match bond type to IR peak NMR: ID number of non-equivalent H s, relate peak splitting to
More informationQuímica Orgânica I. Nuclear Magnetic Resonance Spectroscopy (II) Ciências Farmacêuticas Bioquímica Química AFB QO I 2007/08 1 AFB QO I 2007/08 2
Química Orgânica I Ciências Farmacêuticas Bioquímica Química AFB QO I 2007/08 1 Nuclear Magnetic Resonance Spectroscopy (II) AFB QO I 2007/08 2 1 Adaptado de Organic Chemistry, 6th Edition; L.G. Wade,
More informationTo Do s. Answer Keys are available in CHB204H
To Do s Read Chapters 2, 3 & 4. Complete the end-of-chapter problems, 2-1, 2-2, 2-3 and 2-4 Complete the end-of-chapter problems, 3-1, 3-3, 3-4, 3-6 and 3-7 Complete the end-of-chapter problems, 4-1, 4-2,
More informationMagnetic Resonance Spectroscopy ( )
Magnetic Resonance Spectroscopy In our discussion of spectroscopy, we have shown that absorption of E.M. radiation occurs on resonance: When the frequency of applied E.M. field matches the energy splitting
More informationPAPER No. 12: ORGANIC SPECTROSCOPY. Module 19: NMR Spectroscopy of N, P and F-atoms
Subject Chemistry Paper No and Title Module No and Title Module Tag Paper 12: Organic Spectroscopy CHE_P12_M19_e-Text TABLE OF CONTENTS 1. Learning Outcomes 2. 15 N NMR spectroscopy 3. 19 F NMR spectroscopy
More informationIn a solution, there are thousands of atoms generating magnetic fields, all in random directions.
Nuclear Magnetic Resonance Spectroscopy: Purpose: onnectivity, Map of - framework Process: In nuclear magnetic resonance spectroscopy, we are studying nuclei. onsider this circle to represent a nucleus
More informationSkoog/Holler/Crouch Chapter 19 Principles of Instrumental Analysis, 6th ed. CHAPTER 19
Skoog/Holler/Crouch Chapter 19 Principles of Instrumental Analysis, 6th ed. Instructor s Manual CHAPTER 19 19-1. In a continuous wave NMR experiment, the intensity of the absorption signal is monitored
More informationLecture 6: Physical Methods II. UV Vis (electronic spectroscopy) Electron Spin Resonance Mossbauer Spectroscopy
Lecture 6: Physical Methods II UV Vis (electronic spectroscopy) Electron Spin Resonance Mossbauer Spectroscopy Physical Methods used in bioinorganic chemistry X ray crystallography X ray absorption (XAS)
More information1. Predict the structure of the molecules given by the following spectral data: a Mass spectrum:m + = 116
Additional Problems for practice.. Predict the structure of the molecules given by the following spectral data: a Mass spectrum:m + = IR: weak absorption at 9 cm - medium absorption at cm - NMR 7 3 3 C
More informationStructure Determination
There are more than 5 million organic compounds, the great majority of which are colourless liquids or white solids. Identifying or at least characterising determining some of its properties and features
More informationORGANIC - BROWN 8E CH NUCLEAR MAGNETIC RESONANCE.
!! www.clutchprep.com CONCEPT: 1 H NUCLEAR MAGNETIC RESONANCE- GENERAL FEATURES 1 H (Proton) NMR is a powerful instrumental method that identifies protons in slightly different electronic environments
More informationChemistry 431. Lecture 23
Chemistry 431 Lecture 23 Introduction The Larmor Frequency The Bloch Equations Measuring T 1 : Inversion Recovery Measuring T 2 : the Spin Echo NC State University NMR spectroscopy The Nuclear Magnetic
More informationCH 3. mirror plane. CH c d
CAPTER 20 Practice Exercises 20.1 The index of hydrogen deficiency is two. The structural possibilities include two double bonds, a double do 20.3 (a) As this is an alkane, it contains only C and and has
More informationCan you differentiate A from B using 1 H NMR in each pair?
Can you differentiate A from B using 1 H NMR in each pair? To be NMR active any nucleus must have a spin quantum number, different from zero (I 0) As in 1 H, the spin quantum number (I) of 13 C is 1/2
More information