reading

Cover
Preface to First Edition
1. Acknowledgments
Preface to Second Edition
1. Acknowledgments
Solutions
Symbols
Abbreviations
1 Introduction
1. 1.1 Magnetic Properties of Nuclei
2. 1.2 The Chemical Shift
3. 1.3 Excitation and Relaxation
4. 1.4 Pulsed Experiments
5. 1.5 The Coupling Constant
6. 1.6 Quantitation and Complex Splitting
7. 1.7 Commonly Studied Nuclides
8. 1.8 Dynamic Effects
9. 1.9 Spectra of Solids
10. Problems
11. Tips on Solving NMR Problems
12. References
13. Further Reading
2 Introductory Experimental Methods
1. 2.1 The Spectrometer
2. 2.2 Sample Preparation
3. 2.3 Optimizing the Signal
4. 2.4 Determination of NMR Spectral‐Acquisition Parameters
5. 2.5 Determination of NMR Spectral‐Processing Parameters
6. 2.6 Determination of NMR Spectra: Spectral Presentation
7. 2.7 Calibrations
8. References
9. Further Reading
3 The Chemical Shift
1. 3.1 Factors That Influence Proton Shifts
2. 3.2 Proton Chemical Shifts and Structure
3. 3.3 Medium and Isotope Effects
4. 3.4 Factors That Influence Carbon Shifts
5. 3.5 Carbon Chemical Shifts and Structure
6. 3.6 Tables of Chemical Shifts
7. Problems
8. Further Tips on Solving NMR Problems
9. References
10. Further Reading
11. Chemical Shift Conventions
12. Diamagnetic Anisotropy
13. Van der Waals Effects
14. Empirical Correlations
15. Chemical Shifts of Solvents
16. Solvent Effects
17. Isotope Effects
18. Carbon‐13 Chemical Shifts
19. Other Nuclei (General)
20. Other Nuclei (Specific)
21. Programs for Empirical Calculations
4 The Coupling Constant
1. 4.1 First‐ and Second‐order Spectra
2. 4.2 Chemical and Magnetic Equivalence
3. 4.3 Signs and Mechanisms of Coupling
4. 4.4 Couplings over One Bond
5. 4.5 Geminal Couplings
6. 4.6 Vicinal Couplings
7. 4.7 Long‐range Couplings
8. 4.8 Spectral Analysis
9. 4.9 Second‐order Spectra
10. 4.10 Tables of Coupling Constants
11. References
12. Further Reading
5 Further Topics in One‐Dimensional NMR Spectroscopy
1. 5.1 Spin–Lattice and Spin–Spin Relaxation
2. 5.2 Reactions on the NMR Time Scale
3. 5.3 Multiple Resonance
4. 5.4 The Nuclear Overhauser Effect
5. 5.5 Spectral Editing
6. 5.6 Sensitivity Enhancement
7. 5.7 Carbon Connectivity
8. 5.8 Phase Cycling, Composite Pulses, and Shaped Pulses
9. References
10. Further Reading
11. Carbon‐13 Relaxation
12. Nuclear Overhauser Effect
13. Reactions on the NMR Time Scale
14. Hindered Rotation
15. Ring Reversal and Cyclic Systems
16. Atomic Inversion
17. Organometallics
18. Rates from Relaxation Times
19. Multiple Irradiation
20. Difference Spectroscopy
21. Selective Excitation
22. Broadband Decoupling
23. One‐Dimensional Multipulse Methods
24. Composite Pulses
25. Multiple Quantum Methods
6 Two‐Dimensional NMR Spectroscopy
1. 6.1 Proton–Proton Correlation Through J Coupling
2. 6.2 Proton–Heteronucleus Correlation
3. 6.3 Proton–Proton Correlation Through Space or Chemical Exchange
4. 6.4 Carbon–Carbon Correlation
5. 6.5 Higher Dimensions
6. 6.6 Pulsed Field Gradients
7. 6.7 Diffusion‐Ordered Spectroscopy
8. 6.8 Summary of 2D Methods
9. Problems
10. References
11. Further Reading
12. General
13. COSY
14. Long‐range HETCOR
15. HMBC
16. HOESY
17. EXSY
18. 2D INADEQUATE
19. Solvent Suppression
20. Multiple Quantum Methods
21. Pulsed Field Gradients
22. DOSY
23. PANACEA
7 Advanced Experimental Methods
1. 7.1 Part A: One‐Dimensional Techniques
2. 7.2 Part B: Two‐Dimensional Techniques
3. 7.3 Part C: Two‐Dimensional Techniques: The Experiments
4. References
8 Structural Elucidation: Two Methods
1. 8.1 Part A: Spectral Analysis
2. 8.2 Part B: Computer‐Assisted Structure Elucidation
Appendix A: Derivation of the NMR Equation
Appendix B: The Bloch Equations
1. Reference
Appendix C: Quantum Mechanical Treatment of the Two‐Spin System
Appendix D: Analysis of Second‐Order, Three‐ and Four‐Spin Systems by Inspection
Appendix E: Relaxation
Appendix F: Product‐Operator Formalism and Coherence‐Level Diagrams
1. Reference
Appendix G: Stereochemical Considerations
1. G.1 Homotopics Groups
2. G.2 Enantiotopic Groups
3. G.3 Diastereotopic Groups
4. References
Index
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List of Tables

Chapter 03
1. Table C.1 Two‐spin, first‐order (AX) parameters without coupling (J = 0) and with coupling (J ≠ 0).
2. Table C.2 Parameters for two equivalent spin (A₂) without coupling (J = 0) and with coupling (J ≠ 0).
3. Table C.3 Parameters for two‐spins, second‐order (AB) with coupling (J ≠ 0).
Chapter 07
1. Table G.1 Summary of stereochemical relationships.
Chapter 01
1. Table 1.1 Common first‐order spin–spin splitting patterns.
2. Table 1.2 NMR properties of common nuclei.
Chapter 02
1. Table 2.1 Chemical shift data of common deuterated NMR solvents.a
Chapter 03
1. Table 3.1 Methyl chemical shifts (δ) as a function of solvent (Laszlo).
2. Table 3.2 Carbon substituent parameters for functional groups.
3. Table 3.3 Methyl and methylene groups.
4. Table 3.4 Saturated ring systems.
5. Table 3.5 Alkenes.
6. Table 3.6 Aromatics.
7. Table 3.7 Carbonyl compounds.
Chapter 04
1. Table 4.1 One‐bond coupling constants.
2. Table 4.2 Geminal proton–proton (H--H) coupling constants (Hz).
3. Table 4.3 Vicinal proton–proton (H---H) coupling constants (Hz).
4. Table 4.4 Carbon coupling constants other than ¹ J(¹³-¹H) (Hz).
5. Table 4.5 Nitrogen‐15 coupling constants beyond one bond (Hz).
Chapter 07
1. Table 7.1 Recovered magnetization for various values of T ₁.
Chapter 08
1. Table 8.1 ¹H NMR data.
2. Table 8.2 ¹³C and HSQC NMR Data.
3. Table 8.3 COSY NMR data.
4. Table 8.4 HMBC NMR data.
5. Table 8.5 NOESY NMR data.
6. Table 8.6 T‐2 toxin NMR data.

List of Illustrations

Chapter 02
1. Figure B.1 The equivalence of a linearly oscillating frequency to two oppositely circulating oscillating frequencies.
2. Figure B.2 Phase relationships and the slope of the NMR signal.
Chapter 03
1. Figure C.1 The energy level diagram and the transitions for a first order, two spin system (AX) with J = 0.
2. Figure C.2 Evaluation of the diagonal elements of the Hamiltonian for scalar coupling in a first‐order, two‐spin system (AX).
3. Figure C.3 The energy‐level diagram and the transitions for a first‐order, two‐spin system (AX) with J ≠ 0.
4. Figure C.4 Evaluation of the transition probabilities in a two‐spin system with identical chemical shifts (A₂).
5. Figure C.5 The energy‐level diagram and the transitions for the two‐spin system with identical chemical shifts (A₂) with J = 0.
6. Figure C.6 The energy‐level diagram and the transitions for the two‐spin system with identical chemical shifts (A₂) with J ≠ 0.
7. Figure C.7 Diagonalization of the S _z = 0 Hamiltonian matrix for the second‐order, two‐spin system (AB) and evaluation of the spin state energies.
8. Figure C.8 The energy‐level diagram and the transitions for the second‐order, two‐spin system (AB).
9. Figure C.9 Evaluation of the transition probabilities in the second‐order, two‐spin system (AB).
Chapter 04
1. Figure D.1 The transition from first order (AX₂, bottom) to second order (AB₂, top), with J _AB held at 10 Hz and Δν _AB (Δν _AX) varied: 10 (top), 20, 40, 80, and 160 Hz.
2. Figure D.2 The X portion of an ABX spectrum.
3. Figure D.3 The AB portion of an ABX spectrum.
4. Figure D.4 The A part of an AA′XX′ spectrum.
5. Figure D.5 Two examples of the special case of AA′XX′ spectra (A part) for -CH₂CH₂- fragment in a cyclic compound: (a) when M = 0 and (b) when M is small.
Chapter 05
1. Figure E.1 Plot of spectral density vs logarithm of tumbling frequency.
2. Figure E.2 Logarithmic plot of relaxation times vs the effective correlation time.
Chapter 06
1. Figure F.1 The vector representation of a 90° pulse in the x direction.
2. Figure F.2 Evolution of an uncoupled (J = 0) spin vector with frequency ω over time t in the xy plane.
3. Figure F.3 Evolution of the two vectors from scalar coupling (J) in the xy plane from two perspectives (a) and (b) and resolved into components along the x‐ and y‐axes (c).
4. Figure F.4 Coherence‐level diagram for a 90° pulse.
5. Figure F.5 Coherence‐level diagram for the inversion recovery experiment.
6. Figure F.6 Coherence‐level diagram for the COSY experiment.
7. Figure F.7 Coherence‐level diagram for the NOESY or EXSY experiment.
8. Figure F.8 Coherence‐level diagram for the DQF‐COSY experiment.
9. Figure F.9 Coherence‐level diagram for the 2D INADEQUATE experiment.
Chapter 07
1. Figure G.1 Homotopic ligands (H_a, H_b, H_c).
2. Figure G.2 Coupling of homotopic ligands (H_a, H_b, H_c) with H₁ and H₂.
3. Figure G.3 Enantiotopic ligands (H_a, H_b).
4. Figure G.4 Diastereotopic ligands (H_a, H_b).
Chapter 01
1. Figure 1.1 Analogy between a charge moving in a circle and a spinning nucleus.
2. Figure 1.2 Three classes of nuclei.
3. Figure 1.3 Interaction between a spinning nucleus and an external magnetic field B ₀.
4. Figure 1.4 (a) The energy difference between spin states. (b) The energy difference as a function of the external field B ₀.
5. Figure 1.5 The 300 MHz ¹H spectrum of benzene.
6. Figure 1.6 The energy difference between spin states for three nuclides with various relative magnitudes of the gyromagnetic ratio (|γ|): 26.75 for ¹H, 6.73 for ¹³C, and 2.71 for ¹⁵N.
7. Figure 1.7 The 300 MHz ¹H spectrum (a) and the 75.45 MHz ¹³C spectrum (b) of methyl acetate in CDCl₃. The resonance at δ 77 is from the solvent. The ¹³C spectrum has been decoupled from the protons.
8. Figure 1.8 The resonances that are expected from methyl acetate.
9. Figure 1.9 Spectral conventions.
10. Figure 1.10 Spin‐½ nuclei at equilibrium, prior to application of the B ₁ field.
11. Figure 1.11 Spin‐½ nuclei immediately after application of the B ₁ field.
12. Figure 1.12 Analogy between linearly and circularly oscillating fields.
13. Figure 1.13 (a) Net magnetization M before application of the B ₁ field. (b) After a 30° pulse. (c) After a 90° pulse. (d) After a 180° pulse.
14. Figure 1.14 Time dependence of the magnetization M _y following a 90° pulse (the free induction decay).
15. Figure 1.15 Induced magnetization along the y‐axis as a function of time after a 90° pulse.
16. Figure 1.16 The free induction decay for the ¹H spectra of (a) acetone and (b) methyl acetate. (c) The free induction decay for the ¹³C spectrum of 3‐hydroxybutyric acid. All samples are without solvent.
17. Figure 1.17 The four peaks of a first‐order, two‐spin system (AX): (a) the A portion and (b) the X portion.
18. Figure 1.18 The 300 MHz ¹H spectrum of 1‐chloro‐4‐nitrobenzene in CDCl₃.
19. Figure 1.19 The mechanism for indirect spin–spin coupling.
20. Figure 1.20 The five peaks of a first‐order, three‐spin system (A₂X).
21. Figure 1.21 The 300 MHz ¹H spectrum of 1,1,2‐trichloroethane in CDCl₃.
22. Figure 1.22 The 300 MHz ¹H spectrum of diethyl ether in CDCl₃.
23. Figure 1.23 The seven peaks of the first‐order A₂X₃ spectrum.
24. Figure 1.24 Pascal's triangle.
25. Figure 1.25 (a) The 22.6 MHz ¹³C spectrum of 3‐hydroxybutyric acid, CH₃CH(OH)CH₂CO₂H, without solvent. (b) The ¹³C spectrum of the same compound with proton decoupling.
26. Figure 1.26 The 300 MHz ¹H spectrum of ethyl trans‐crotonate (CH₃CH=CH(CO)OCH₂CH₃) in CDCl₃. The upper multiplets are expansions of three resonances. The continuous lines above or through a resonance is its integral.
27. Figure 1.27 Overlapping peaks of the resonance δ 6.98, which arise when nuclei are unequally coupled to more than one other set of spins.
28. Figure 1.28 Overlapping peaks of the resonance at δ 5.84 (not to scale).
29. Figure 1.29 Overlapping peaks of the resonance at δ 1.88 (not to scale).
30. Figure 1.30 The 60 MHz ¹H spectrum of CH₃OH at +50 °C (a) and at −30 °C (b).
31. Figure 1.31 The 60 MHz ¹H spectrum of cyclohexane‐d₁₁ as a function of temperature.
32. Figure 1.32 Anisotropy of shielding in the solid state.
33. Figure 1.33 The ¹³C spectrum of polycrystalline β‐quinol methanol clathrate (a) without dipolar decoupling, (b) with decoupling, and (c) with both decoupling and magic angle spinning.
Chapter 02
1. Figure 2.1 Effects of misadjusted shim settings. (a) Z3 misset, (b) Z5 misadjusted, (c) Z2 misset, and (d) Z4 misadjusted. (e) First‐order spinning sidebands: X, Y, XZ, and YZ misset. (f) Second‐order spinning sidebands: XY and X2–Y2 misadjusted on top of first‐order sidebands. (g) High‐order nonspin shims: X3, Y3, Z3X, and Z3Y misset. (h) Z1, Z2, and Z4 misadjusted. These spectral effects have been exaggerated for the purpose of illustration.
2. Figure 2.2 (a) Sampling a sine wave exactly two times per cycle. (b) Sampling a sine wave less than twice per cycle. (c) The lower frequency sine wave that contains the same points as in (b) and is sampled more than twice per cycle. The frequency of (b) is not detected, but appears as an aliased peak at the frequency of (c).
3. Figure 2.3 Aliasing of signals. (a) Normal spectrum, with all of the signals at their correct chemical shifts. (b) The highest‐frequency signal has wrapped around into the spectrum at the low‐frequency end. (c) The same signal has folded back into the spectrum at the high‐frequency end. The appearance of aliased signals (denoted by an asterisk) is distorted in both cases.
4. Figure 2.4 Plot used to identify optimum flip angle (Ernst angle).
5. Figure 2.5 A typical ¹H one‐dimensional NMR pulse sequence.
6. Figure 2.6 A typical one‐dimensional pulse sequence for the observation of ¹³C (b) while irradiating ¹H (a).
7. Figure 2.7 Weighting functions. (a) Sensitivity enhancement. (b) Resolution enhancement.
8. Figure 2.8 The effect of multiplying a free‐induction decay by a line‐broadening factor of 3, 2, 1, and 0 Hz.
9. Figure 2.9 The effect of multiplying a free‐induction decay by a resolution enhancement function (a) and the normal spectrum (b).
10. Figure 2.10 The effects of truncating a signal. (a) A truncated FID (left) showing truncation wiggles at the base of the Fourier‐transformed signal (right). (b) Exponential weighting function for apodization. (c) The apodized FID (left) and Fourier‐transformed signal (right). While the truncation wiggles have been removed, the resulting signal has been broadened.
11. Figure 2.11 Comparison of shapes of absorption (solid line) and dispersion (dotted line) signals. Spectra are usually phase corrected to give pure absorption‐mode peaks. The arrows indicate the full width at half maximum.
12. Figure 2.12 ¹H spectra showing zero‐ and first‐order phase errors. (a) The spectrum of Ibuprofen (2‐(4‐isobutylphenyl)propanoic acid) with frequency‐independent (zero‐order) phase errors. (b) The spectrum with frequency‐dependent (first‐order) phase errors. (c) The correctly phased spectrum.
13. Figure 2.13 Apparent phase errors due to signal‐truncation effects. (a) The distorted spectrum of Ibuprofen caused by an acquisition time that is too short (DT = 0 second). (b) The distortion‐free spectrum after the introduction of a relaxation delay time (DT = 1 second).
14. Figure 2.14 A typical 90° pulse width calibration plot.
Chapter 03
1. Figure 3.1 (a) An unshielded nucleus. Nuclei shielded by (b) local and (c) nonlocal currents.
2. Figure 3.2 Shielding by a spherical (isotropic) group. (a) When the -H bond is parallel to the direction of the magnetic field. (b) When the -H bond is perpendicular to the direction of the magnetic field.
3. Figure 3.3 Shielding by an oblate ellipsoid, the model for aromatic rings. (a) When the plane of the oblate ellipsoid is perpendicular to the direction of the magnetic field. (b) When the plane of the oblate ellipsoid is parallel to the direction of the magnetic field.
4. Figure 3.4 Shielding geometry for a benzene ring.
5. Figure 3.5 Shielding by a prolate ellipsoid, the model for a chemical bond. (a) When the triple bond is parallel to the direction of the magnetic field. (b) When the triple bond is perpendicular to the direction of the magnetic field.
6. Figure 3.6 (a) Shielding region around a carbon–carbon single bond. (b) Geometry of a cyclohexane ring.
7. Figure 3.7 Shielding properties of methyl, methylene, and methine groups.
8. Figure 3.8 Diamagnetic anisotropic properties of (a) the C=C double bond and (b) the C=O double bond. These properties are altered by perturbations of the electronic structure by nearby atoms.
9. Figure 3.9 Proton chemical shift ranges for common structural units. The symbol CH represents methyl, methylene, or methine, and R represents a saturated alkyl group. The range for -CO₂H and other strongly hydrogen‐bonded protons is off scale to the left. The indicated ranges are for common examples; actual ranges can be larger.
10. Figure 3.10 The 300 MHz ¹H spectrum of nitrobenzene in CDCl₃.
11. Figure 3.11 Carbon chemical‐shift ranges for common structural units. The symbol C represents methyl, methylene, methine, or quaternary carbon; R represents a saturated alkyl group. The indicated ranges are for common examples; actual ranges can be larger.
12. Figure 3.12 Calculation of the ¹³C chemical shifts of pentane.
13. Figure 3.13 Calculation of the ¹³C chemical shifts of the indicated carbon in 2‐methylpropane (isobutane) and in 2,2‐dimethylpropane (neopentane).
14. Figure 3.14 The anti and gauche geometries in a butane fragment.
15. Figure 3.15 Calculation of the ¹³C chemical shifts of the indicated carbons in 1,3‐dichloropropane and in cyclopentanol.
Chapter 04
1. Figure 4.1 The two‐spin spectrum with Δν/J values of 0.4 (top), 1.0, 4.0, and 15.0.
2. Figure 4.2 The 90 MHz ¹H spectrum of 1,1‐difluoroethene in CDCl₃.
3. Figure 4.3 The 300 MHz ¹H spectrum of 1,2‐dichlorobenzene in CDCl₃. An impurity is signified by the letter i.
4. Figure 4.4 The 300 MHz ¹H spectrum of 2‐chloroethanol (methylene resonances only) in CDCl₃.
5. Figure 4.5 Diagram of the Fermi contact mechanism for the indirect coupling of two spins.
6. Figure 4.6 The vicinal H---H coupling constant as a function of the dihedral angle φ.
7. Figure 4.7 Coupling magnitudes between vicinal protons in chair six‐membered rings (axial protons are designated by the letter a and equatorial protons by the letter e).
8. Figure 4.8 The 300 MHz ¹H spectrum of acrylonitrile (CH₂=CHCN) in CDCl₃.
9. Figure 4.9 Notation for spacings in a second‐order, two‐spin system (AB).
10. Figure 4.10 (a) A deceptively simple ABX spectrum: ν _A = 0.0 Hz, ν _B = 3.0 Hz, ν _X = 130.0 Hz, J _AB = 15.0 Hz, J _AX = 5.0 Hz, and J _BX = 3.0 Hz. (b) The same parameters, except that ν _B = 8.0 Hz. The larger value of Δν _AB removes the deceptive simplicity and produces a typical ABX spectrum.
11. Figure 4.11 (left) The 60 MHz methyl ¹H resonance of β‐methylglutaric acid. (right) The 60 MHz spectra of the 2,5‐ and 2.6 dimethylquinones.
12. Figure 4.12 The 90 MHz ¹H spectrum of cyclopropene, showing the observed (a) and calculated (b) high‐frequency ¹³C satellite of the alkenic protons.
Chapter 05
1. Figure 5.1 The inversion recovery experiment. (a) Initial condition. (b) After 180° pulse. (c) After τ period. (d) After final 90° pulse.
2. Figure 5.2 A stack plot for the inversion recovery experiment of the ¹³C resonances of chlorobenzene at 25 MHz. The time τ in the pulse sequence 180° – τ – 90° is given in seconds at the right.
3. Figure 5.3 The spin states for a nucleus with I = 1.
4. Figure 5.4 The 90 MHz proton spectrum of pyrrole with (a) and without (b) ¹⁴N decoupling.
5. Figure 5.5 The ¹H spectrum of ethyl trans‐crotonate. The inset contains an expansion of the alkenic range (a) without and (b) with decoupling of the methyl resonance at δ 1.8.
6. Figure 5.6 The 100 MHz ¹H spectrum of mannosan triacetate in CDCl₃ without decoupling (a) and with double irradiation at δ 4.62 (b).
7. Figure 5.7 The 400 MHz ¹H spectrum of 1‐dehydrotestosterone. The complete spectrum and an expansion of the low‐frequency region are given on the left. On the right are shown (a) the coupled spectrum for the δ 0.9–1.1 region; (b) the same region, decoupled from the 6α proton; and (c) the difference spectrum obtained by subtracting (b) from (a).
8. Figure 5.8 The ¹³C spectrum of vinyl acetate (a) with complete decoupling of the protons and (b) with off‐resonance decoupling of the protons.
9. Figure 5.9 Pulse sequence to remove heteronuclear coupling.
10. Figure 5.10 (a) The spin states for a normal two‐spin (AX) system. (b) The spin states for an AX system when the frequency of A is doubly irradiated. Arrows denote spin excitations.
11. Figure 5.11 (a) Observation of ¹³C with continuous double irradiation of ¹H (decoupling and NOE). (b) Double irradiation applied during acquisition, but gated off during the wait period (decoupling, no NOE). (c) Double irradiation applied only during the wait period (NOE, no decoupling). The pulse widths are not to scale. The scheme is shown for two cycles.
12. Figure 5.12 The 400 MHz ¹H spectrum (in part) of progesterone (a) without double irradiation and (b) with irradiation of the CH₃–19 resonance displayed as a difference spectrum.
13. Figure 5.13 Spin echo experiment to eliminate the effects of B ₁ inhomogeneity.
14. Figure 5.14 Pulse sequence that allows spin vectors to evolve to an arbitrary frequency separation φ.
15. Figure 5.15 Pulse sequence for spectral editing of a methine (CH) resonance.
16. Figure 5.16 Pulse sequence for spectral editing of a methylene (CH₂) resonance.
17. Figure 5.17 (a) The normal proton‐decoupled ¹³C spectrum of cholesteryl acetate. (b) The attached proton test (APT), phased so that CH₂ and quaternary carbons are positive and CH and CH₃ carbons are negative.
18. Figure 5.18 Spectral editing of the 75.6 MHz ¹³C spectrum of the trisaccharide gentamycin by the DEPT sequence. The bottom spectrum contains resonances of all carbons with attached protons, and the ascending spectra are respectively of the methine, methylene, and methyl carbons.
19. Figure 5.19 Pulse sequence for the INEPT experiment, showing the effects on the ¹H spin vectors.
20. Figure 5.20 Spin states for a two‐spin (¹³-¹H) system, normally (a) and after the INEPT pulse sequence (b).
21. Figure 5.21 The proton‐coupled ¹³C spectrum of pyridine, (a) with INEPT, (b) with NOE only, and (c) unenhanced, all on the same scale.
22. Figure 5.22 The ¹³C spectrum of chloroform (a) without double irradiation, (b) with ¹H irradiation to achieve the INEPT enhancement, (c) with ¹H irradiation to achieve refocused INEPT enhancement, (d) with ¹H irradiation to achieve refocused INEPT enhancement and decoupling, and (e) with normal decoupling to achieve only the NOE.
23. Figure 5.23 Intensities of the carbon resonances of an imaginary molecule containing one CH, one CH₂, and one CH₃ under varying values of Δ₂ in the refocused INEPT experiment.
24. Figure 5.24 Variation of signal intensities for CH, CH_2, and CH₃ as a function of θ = πJΔ₂ in the refocused INEPT experiment.
25. Figure 5.25 The one‐dimensional INADEQUATE spectrum for the carbons of piperidine.
26. Figure 5.26 Phase cycling in the inversion recovery experiment.
27. Figure 5.27 A composite pulse equivalent to a single 180° pulse.
28. Figure 5.28 (a) The result of Fourier transformation of a low‐power rectangular pulse. (b) The result for a shaped Gaussian pulse.
Chapter 06
1. Figure 6.1 The pulse arrangements for a single cycle of one‐dimensional NMR spectroscopy (a) and for two‐dimensional NMR correlation spectroscopy (COSY) (b). In this diagram, each pulse is 90°. Data are acquired during the time t in the one‐dimensional experiment and during t ₂ in the two‐dimensional experiment.
2. Figure 6.2 The pulse sequence for the COSY experiment. (a) Initial condition. For (c′), the magnetization M is allowed to evolve a longer time from (b) before the final pulse is applied to give (d′) than was the case from (b) for (c), which would give (d) after the final pulse.
3. Figure 6.3 The solid line slanting upward at frequency ν _A in the horizontal plane serves as the baseline for a series of ¹H spectra of chloroform, according to the COSY pulse sequence for a series of values of t ₁. Each peak results from one cycle of 90°–t ₁–90°‐acquire, followed by Fourier transformation during t ₂ (Figure 6.1) to give frequency ν _A on the axis labeled ν ₂ (corresponding to the time domain t ₂). The period t ₁ is ramped up after each cycle. Fourier transformation in the t ₁ dimension has not been carried out.
4. Figure 6.4 (a) The result of the COSY experiment after double Fourier transformation for a single isolated nucleus such as that in Figure 6.3. (b) The result of the COSY experiment for two uncoupled nuclei.
5. Figure 6.5 The energy diagram for an AX spin system.
6. Figure 6.6 The stacked representation of the COSY experiment for the two coupled nuclei of β‐chloroacrylic acid.
7. Figure 6.7 The contour representation of the COSY experiment for two coupled nuclei of β‐chloroacrylic acid.
8. Figure 6.8 The COSY experiment for the illustrated annulene.
9. Figure 6.9 (a) The 300 MHz ¹H spectrum of the tripeptide Pro–Leu–Gly in DMSO. (b) COSY spectrum of Pro–Leu–Gly with connectivities of the NH protons.
10. Figure 6.10 (a) Connectivity within the leucine portion of Pro–Leu–Gly by COSY. (b) Connectivity within the proline portion of Pro–Leu–Gly by COSY.
11. Figure 6.11 The fully assigned ¹H spectrum of Pro–Leu–Gly.
12. Figure 6.12 The COSY90 (a) and COSY45 (b) spectra of 2,3‐dibromopropionic acid. (c) The 1D spectrum is a cross section through the COSY45 spectrum.
13. Figure 6.13 The 400 MHz COSY (a) and LRCOSY (b) spectra of naphthobiphenylene dianion. (The signal S is from solvent.)
14. Figure 6.14 The four types of 2D phase quadrants, corresponding to frequency modes that are real–real (RR), imaginary–real (IR), real–imaginary (RI), and imaginary–imaginary (II).
15. Figure 6.15 Phase‐sensitive COSY diagram for two spins, with the diagonal peaks in dispersion mode and the cross peaks in antiphase absorption mode. The 1D spectrum is on the right.
16. Figure 6.16 The (a) DQF‐COSY and (b) TOCSY spectra of lysine.
17. Figure 6.17 Diagram of (a) COSY and (b) relayed coherence transfer (RCT) experiments for two three‐spin systems (AMX and A′M′X′) whose M and M′ portions overlap.
18. Figure 6.18 The 270 MHz 2D J‐resolved ¹H spectrum of 2,3,4,6‐tetrakis‐O‐trideuteroacetyl‐α‐D‐glucopyranoside.
19. Figure 6.19 The pulse sequence for the HETCOR experiment.
20. Figure 6.20 The pulse sequence for the HETCOR experiment with decoupling.
21. Figure 6.21 The HETCOR spectrum of 4‐(methoxycarbonyl)adamantane‐2,6‐dione.
22. Figure 6.22 The pulse sequence for the HMQC experiment.
23. Figure 6.23 The HMQC spectrum of camphor, with ¹H–¹³C couplings retained in the ¹H dimension.
24. Figure 6.24 The BIRD sequence for the selection of signals from protons attached to ¹³C over those from protons attached to ¹²C.
25. Figure 6.25 The COLOC spectrum of vanillin.
26. Figure 6.26 The pulse sequence for the HMBC experiment.
27. Figure 6.27 The HMBC spectrum of the illustrated heterocycle. The 1D ¹H spectrum is given at the top. The vertical axis corresponds to ¹³C frequencies, the horizontal axis to ¹H frequencies. One‐bond correlations are indicated by peaks connected by doubly headed arrows.
28. Figure 6.28 (a) The ¹³C and ¹H spectra of the dimethyl acetal of acrolein. (b) The normal HETCOR (labeled HSC, bottom) and the H–H–C relay coherence transfer (top) experiments for the same molecule.
29. Figure 6.29 The ¹H NOESY spectrum for the indicated compound.
30. Figure 6.30 Peak intensities calculated for a hypothetical NOESY experiment involving four nuclei, D–A–B–C, with D 4 Å from A and B 2 Å from A and C. The curve labeled AA is for the diagonal peak, and the remaining curves are for the various cross peaks.
31. Figure 6.31 The enhancement factor η as a function of the effective correlation time τ _c for the standard nuclear Overhauser experiment (NOE) and for the spin‐lock, or rotating‐coordinate, variant (ROE). The curves were calculated for an interproton distance of 2.0 Å and a spectrometer frequency of 500 MHz.
32. Figure 6.32 The ¹H EXSY spectrum for the heptamethylbenzenium ion.
33. Figure 6.33 The 2D INADEQUATE spectrum of menthol, with the ¹H‐decoupled ¹³C spectrum.
34. Figure 6.34 A portion of the NOESY spectrum of a DNA‐binding protein of phage Pf3 containing cross peaks between NH and aliphatic protons.
35. Figure 6.35 The ¹H/¹⁵N HMQC spectrum of ¹⁵N‐labeled Pf3. The arrows are explained in Figure 6.38.
36. Figure 6.36 The pulse sequence for the 3D NOESY/HMQC experiment.
37. Figure 6.37 Diagram of the 3D NOESY–(¹H/¹⁵N)HMQC spectrum of Pf3 in three frequency dimensions: F ₁, F ₂, and F ₃ (ν ₁, ν ₂, and ν ₃).
38. Figure 6.38 Two ν ₁–ν ₃ (F ₁–F ₃) planes taken from the 3D NOESY–(¹H/¹⁵N)HMQC spectrum of Pf3, corresponding to the frequencies indicated by arrows in Figure 6.35.
39. Figure 6.39 Diagram of a B ₀ field gradient along the z direction.
40. Figure 6.40 Editing of the ¹H spectrum of brucine (6.3) into subspectra for CH₃, CH₂, and CH (top to bottom). The complete ¹H spectrum is given at the bottom.
41. Figure 6.41 The double pulse field gradient spin echo (DPFGSE) NOE experiment for 11β‐hydroxyprogesterone: (a) the unirradiated spectrum and (b)–(g) spectra with irradiation at selected frequencies.
42. Figure 6.42 (b) Water suppression with excitation sculpting on 2 mM sucrose in 9 : 1 H₂O/D₂O. (a) The residual solvent peak has been eliminated by further processing.
43. Figure 6.43 The DOSY spectrum of a mixture of polyvinyl chloride (PVC), dioctyl phthalate (DOP), and tetrahydrofuran (THF).
Chapter 07
1. Figure 7.1 An inversion‐recovery experiment. Signal intensities are shows as a function of τ.
2. Figure 7.2 The APT pulse sequence.
3. Figure 7.3 The NOE difference pulse sequence.
4. Figure 7.4 (a) NOE difference and (b) double pulsed field gradient spin echo NOE for T‐2 toxin.
5. Figure 7.5 The double pulsed field gradient spin echo NOE pulse sequence. The relative strengths of gradients G ₁, G ₂, and G _m are 16, 7, and 13 G cm⁻¹, respectively. The mixing time is 650 ms.
6. Figure 7.6 Weighting functions. (a) Sine bell. (b) Squared sine bell. (c) Shifted sine bell. (d) Shifted, squared sine bell. (e) Gaussian. (f) Cosine (90°‐shifted sine bell). (g) Squared cosine (90°‐shifted, squared sine bell).
7. Figure 7.7 Expanded HSQC spectra with 16‐fold linear prediction (a) and no linear prediction (b).
8. Figure 7.8 The gradient COSY pulse sequence.
9. Figure 7.9 Expansions of the COSY spectrum (a) and the COSY‐45 spectrum (b) for T‐2 toxin.
10. Figure 7.10 The COSY spectra with high resolution (a) and low resolution (b) for T‐2 toxin.
11. Figure 7.11 The COSY spectrum (a) and DQF‐COSY spectrum (b) of T‐2 toxin.
12. Figure 7.12 The TOCSY pulse sequence.
13. Figure 7.13 The COSY spectrum (a) and TOCSY spectrum (b) of T‐2 toxin. The TOCSY mixing time is 80 ms.
14. Figure 7.14 (a) The HMQC spectrum (left) and HSQC spectrum (right). (b) Expansions of HMQC spectrum (left) and HSQC spectrum (right) of T‐2 toxin.
15. Figure 7.15 The HSQC spectrum (a) and gradient HSQC spectrum (b) of T‐2 toxin.
16. Figure 7.16 The gradient HSQC pulse sequence. The relative strengths of gradients G ₁ and G ₂ are 4 and 1 G cm⁻¹, respectively, as shown, when X = ¹³C.
17. Figure 7.17 The gradient HMBC pulse sequence. The relative strengths of gradients G ₁, G ₂, and G ₃ are 5, 3, and 4 G cm⁻¹, respectively, as shown, when X = ¹³C.
18. Figure 7.18 The HMBC spectrum (a) and gradient HMBC spectrum (b) of T‐2 toxin.
19. Figure 7.19 The FLOCK pulse sequence. The 180° ¹H pulses in parentheses are BIRD pulses (90°–τ–180°–τ–90°) with τ = (2J _CH)⁻¹. The relative phases of the three pulses are x, y, −x for the first BIRD pulse and x, x, −x for the second and third BIRD pulses.
20. Figure 7.20 The resolution enhancement of the FLOCK experiment (red) over the proton detected HMBC (black) for oleic acid in the crowded region of the carbon dimension. The trade‐off is in sensitivity. The HMBC can be up to an order of magnitude more sensitive.
21. Figure 7.21 The HSQC–TOCSY pulse sequence.
22. Figure 7.22 The HSQC spectrum (a) and the HSQC–TOCSY spectrum (b) of T‐2 toxin.
23. Figure 7.23 The NOESY spectrum (a) and the T‐ROESY spectrum (b) for T‐2 toxin.
24. Figure 7.24 The 1D‐TOCSY spectra for a four‐spin system of T‐2 toxin for mixing times of 0 ms (c), 120 ms (b), and 300 ms (a).
25. Figure 7.25 Comparison spectra: selective 1D‐TOCSY (c), 2D‐TOCSY trace (b), and HSQC–TOCSY trace (a).
26. Figure 7.26 The multiplicity‐edited gradient HSQC pulse sequence. The relative strengths of gradients G ₁ and G ₂ are 4 and 1 G cm⁻¹, respectively, as shown, when X = ¹³C.
27. Figure 7.27 Expansions of the HSQC spectrum (a) and the multiplicity‐edited spectrum (b) of T‐2 toxin. The colors red and blue correspond to positive and negative peaks.
28. Figure 7.28 The H2BC pulse sequence. Time T is adjusted to make the constant time, CT, around 20 ms. Delays Δ₁–Δ₃ are part of a low‐pass J filter and are set to the inverse of an average, a low and a high value of ¹ J _CH, respectively. Gradients G ₁ and G ₂ alternate polarity for echo/anti‐echo selection and gradients G ₃–G ₅ are set for coherence selection. Gradient strengths for G ₁–G ₅ are 10, 10, 1.51, 3.52, and 10.1 G cm⁻¹, respectively.
29. Figure 7.29 The HMBC (a) and H2BC (b) spectra of T‐2 toxin. The ¹H spectrum is shown on top and the carbon spectrum is shown vertically on the left.
30. Figure 7.30 50% NUS sampled data from the indirect dimension of an HSQC experiment is shown in (a). The same data reconstructed to the full 256 point grid is in (b).
31. Figure 7.31 The NUS HSQC spectra of T‐2 toxin. The spectra are multiplicity edited so that CH and CH₃ correlations are red and CH₂ peaks are blue. (a) Conventional sampling, ni = 128, t = 6 minutes, (b) 25% sampled with 36 NUS increments on a 128 point grid, t = 2 minutes, (c) conventional sampling, ni = 512, t = 22 minutes, (d) 25% sampled 128 NUS increments from a 512 point grid, t = 6 minutes. Both (a) and (d) were acquired in 6 minutes but (d) has the same resolution as (c), which took 22 minutes to acquire. The S/N is roughly the same in all. There are some artifacts that appear close to the noise level in the NUS experiments.
32. Figure 7.32 The 1D ¹H spectra of menthol. Conventional (a), Zangger–Sterk pure shift (b), PSYCHE pure shift (c). The vertical scale of the pure‐shift spectra were increased by ∼600 times compared with the normal 1D.
33. Figure 7.33 The multiplicity‐edited HSQC spectra of menthol. Conventional (a) and pure shift (b). The geminal protons in blue are not ¹H‐decoupled from each other and so the resolution enhancement along f ₂ is not so large as for the CH and CH₃ protons in red.
34. Figure 7.34 Sections of the COSY spectra of T2‐toxin: (a) conventional and (b) direct covariance. The resolution enhancement in the covariance processed spectrum is apparent along f ₁. The regular ¹H spectrum is attached on the top and left side.
35. Figure 7.35 The HSQC–TOCSY spectra of T‐2 toxin: (a) conventional and (b) covariance (HSQC + TOCSY). The vertical traces on the left of each spectrum show the f ₁ projections that are compared in Figure 7.36. The regular ¹H spectrum is on the top.
36. Figure 7.36 The HSQC–TOCSY f ₁ projections of T‐2 toxin: (a) conventional and (b) covariance (HSQC + TOCSY). The S/N is approximately 10 times larger in the covariance‐processed spectrum.
Chapter 08
1. Figure 8.1 The 500‐MHz ¹H NMR spectrum of T‐2 toxin.
2. Figure 8.2 The 125 MHz ¹³C NMR spectrum of T‐2 toxin.
3. Figure 8.3 DEPT subspectra of T‐2 toxin.
4. Figure 8.4 Molecular fragments established by COSY correlations.
5. Figure 8.5 Generalized two‐ and three‐bond -H couplings.

Nuclear Magnetic Resonance Spectroscopy

An Introduction to Principles, Applications, and Experimental Methods

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Preface to First Edition

Acknowledgments