High Resolution NMR: Theory and Chemical Applications focuses on the applications of nuclear magnetic resonance (NMR), as well as chemical shifts, lattices, and couplings. The book first offers information on the theory of NMR, including nuclear spin and magnetic moment, spin lattice relaxation, line widths, saturation, quantum mechanical description of NMR, and ringing. The text then ponders on instrumentation and techniques and chemical shifts. Discussions focus on the origin of chemical shifts, reference compounds, empirical correlations of chemical shifts, modulation and phase detection, requirements for high resolution NMR, and superconducting magnets. The text elaborates on electron-coupled spin-spin interactions, as well as origin of spin-spin coupling, signs of coupling constants, theory of spin-spin coupling, correlation of coupling constants with other physical properties, and observed coupling constant. The manuscript also ponders on the use of NMR in structure elucidation, theory and applications of double resonance, and analysis of complex spectra. The publication is a dependable reference for readers interested in high resolution NMR.
Inhalt
Preface
Acknowledgments
1. Introduction
1.1 Historical
1.2 High Resolution NMR
References
2. The Theory of NMR
2.1 Nuclear Spin and Magnetic Moment
2.2 Classical Mechanical Description of NMR
2.3 Quantum Mechanical Description of NMR
2.4 Effect of the Boltzmann Distribution
2.5 Spin-Lattice Relaxation
2.6 Line Widths
2.7 Saturation
2.8 The Bloch Equations; Nuclear Induction
2.9 Ringing
References
Problems
3. Instrumentation and Techniques
3.1 Basic NMR Apparatus
3.2 Requirements for High Resolution NMR
3.3 Modulation and Phase Detection
3.4 Field/Frequency Control
3.5 Signal/Noise and Size of Sample
3.6 Superconducting Magnets
3.7 Intensity Measurements
3.8 References
3.9 Magnetic Susceptibility Measurements
3.10 Frequency Calibration
3.11 Control of Sample Temperature
3.12 Useful Solvents
3.13 Sampling Techniques
3.14 Micro Techniques
3.15 Adiabatic Rapid Passage
3.16 Pulse Techniques
3.17 Double Resonance Techniques
References
Problems
4. Chemical Shifts
4.1 The Origin of Chemical Shifts
4.2 Reference Compounds
4.3 Chemical Shift Scales
4.4 Magnetic Susceptibility Correction
4.5 Empirical Correlations of Chemical Shifts
4.6 Theory of Chemical Shifts
4.7 Effect of Electron Density
4.8 Magnetic Anisotropy and Chemical Shifts
4.9 Ring Currents
4.10 Paramagnetic Species
4.11 Nuclei Other than Hydrogen
4.12 Tabulations of Chemical Shifts and Spectra
4.13 Empirical Estimation of Chemical Shifts
References
Problems
5. Electron-Coupled Spin-Spin Interactions
5.1 Origin of Spin-Spin Coupling
5.2 Coupling between Groups of Equivalent Nuclei
5.3 First-Order Analysis
5.4 Signs of Coupling Constants
5.5 Theory of Spin-Spin Coupling
5.6 Some Observed Coupling Constants
5.7 Correlation of Coupling Constants with Other Physical Properties
References
Problems
6. The Use of NMR in Structure Elucidation
6.1 A Systematic Approach to the Interpretation of NMR Spectra
6.2 Spectra of Polymers in Solution
References
Problems
7. Analysis of Complex Spectra
7.1 Notation
7.2 Energy Levels and Transitions in an AX System
7.3 Quantum Mechanical Formalism
7.4 Nuclear Spin Basis Functions
7.5 The Spin Hamiltonian
7.6 The Two-Spin System without Coupling
7.7 Factoring the Secular Equation
7.8 Two Coupled Spins
7.9 Selection Rules and Intensities
7.10 The AB Spectrum
7.11 Spectral Contributions from Equivalent Nuclei
7.12 Symmetry of Wave Functions
7.13 Summary of Rules for Calculating Spectra
7.14 The Three-Spin System: ABC
7.15 The A2B System
7.16 The A3B System; Subspectral Analysis
7.17 The ABX System
7.18 Analysis of an ABX Spectrum
7.19 Relative Signs of JAX and JBX in an ABX Spectrum
7.20 ABX Patterns; Deceptively Simple Spectra
7.21 "Virtual Coupling"
7.22 The AA'BB' and AA'XX' Systems
7.23 Other Complex Spectra
7.24 Aids in the Analysis of Complex Spectra
7.25 Use of Liquid Crystals as Solvents
References
Problems
8. Theory and Application of Double Resonance
8.1 Notation and Terminology
8.2 Experimental Techniques
8.3 Theory of Double Resonance
8.4 Structure Elucidation
8.5 Location of "Hidden" Lines
8.6 Determination of Chemical Shifts
8.7 Relative Signs of Coupling Constants
8.8 Determination of Energy Level Arrangements
8.9 Other Applications
References
Problems
9. Relaxation
9.1 Processes for Spin-Lattice Relaxation
9.2 Nuclear Magnetic Dipole Interactions
9.3 The Effect of Anisotropic Shielding
9.4 Electric Quadrupole Relaxation
9.5 Relaxation by Paramagnetic Substances
9.6 Chemical Applications
9.7 Measurement of Relaxation Times
References
Problems
10. Effects of Exchange Processes
10.1 Spectra of Exchanging Systems
10.2 Theory of Chemical Exchange
10.3 Collapse of Spin Multiplets
10.4 More Complete Theories of Exchange
10.5 Double Resonance and Pulse Techniques
10.6 Asymmetry and Internal Rotation
References
Problems
11. Solvent Effects and Hydrogen Bonding
11.1 Medium Effects on Chemical Shifts
11.2 Solvent Effects on Coupling Constants
11.3 Solvent Effects on Relaxation and Exchange Rates
11.4 Hydrogen Bonding
References
12. Use of NMR in Quantitative Analysis
12.1 Advantages of NMR in Quantitative Analysis
12.2 Drawbacks and Problems in the Use of NMR in Quantitative Analysis
12.3 Some Analytical Uses of NMR
References
Appendix A Nuclear Spins, Magnetic Moments, Resonance Frequencies
Appendix B Proton NMR Spectra of "Unknowns"
Appendix C General NMR References
Appendix D Answers to Selected Problems
Subject Index