NMR of Paramagnetic Molecules

NMR of Paramagnetic Molecules: Principles and Applications is a compendium of papers that discusses the physical principles behind the technique of nuclear magnetic resonance, as well as, evaluates the scope and limitation of the applications of NMR in chemistry and biology. These papers emphasize the applications of the technique in chemistry and biochemistry where it widely used, particularlyon NMR experiments in the liquid state. Some papers describe the theoretical factors governing the resonance position and linewidth, and then also interpret magnetic resonance parameters in terms of electronic structure. Another paper investigates the gap between the mathematical complexities of earlier experiments and the operational aspects of chemical information from the spectra. Examples show studies in biochemical molecules and process in events where contact interactions are present either as a result of intrinsic molecular paramagnetism or are just induced through the addition of suitable paramagnetic probes. One paper presents the definitive and controversial results involving stereochemistry and deuterium NMR. This collection of papers will prove useful for nuclear physicists, researchers, and academicians in the field of nuclear physics.

Contenu

List of Contributors

Preface

1. The Paramagnetic Shift

   I. Introduction

   II. High-Resolution Nuclear Magnetic Resonance in Diamagnetic Systems

   III. Electron Paramagnetic Resonance in the Hydrogen Atom

   IV. High-Resolution Nuclear Magnetic Resonance in a Simple Paramagnetic System

   V. General Treatment of High-Resolution Nuclear Magnetic Resonance Shifts in Paramagnetic Systems

   VI. Application of the General Theory

   VII. Other Factors Affecting the Paramagnetic Shift

   VIII. Summary

   Appendix: Density Matrix Theory

   References

2. The Paramagnetic Linewidth

   I. Introduction

   II. Magnetic Relaxation and the NMR Line Shape

   III. Mechanisms of Nuclear Spin-Lattice Relaxation

   IV. Electron-Spin Relaxation

   References

3. Spin Delocalization and Electronic Structure

   I. Introduction

   II. Spin Density and Electron Correlation

   III. Hyperfine Coupling Constants and Spin Density

   IV. Spin Delocalization and Spin Polarization

   V. Metal-Ligand Covalency

   References

4. Analysis of Isotropic Shifts

   I. Introduction

   II. Determination of the Origin of Observed Shifts

   III. Characterization of Contact Shifts by Quantum Mechanical Models

   References

5. Spin Distribution in Organic Ligands

   I. Introduction

   II. Qualitative Applications of Ligand Spin Density Measurements

   III. The Quantitative Assessment of Spin Density Distributions

   IV. The Effect of Other Ligands on Spin Density Distributions

   V. Conclusion

   References

6. Spin Distribution in Organometallic Compounds

   I. Introduction

   II. Bis-p-Cyclopentadienyl Complexes: Results

   III. Discussion of Bis-p-Cyclopentadienyl Complexes

   IV. Bis-Arene Organometallics: Results

   V. Discussion of Bis-Arene Organometallics

   VI. Contact Shifts of Other Organometallics

   VII. Conclusions

   References

7. Stereochemistry and Structural and Electronic Equilibria

   I. Introduction

   II. Stereochemistry and Structural Equilibria

   III. Spin Equilibria

   Appendix

   References

8. Dynamics of Intramolecular Rearrangements

   I. Introduction

   II. Metal-Centered Rearrangements

   III. Ligand-Centered Rearrangements

   References

9. Solvation and the Second Coordination Sphere

   I. Introduction

   II. Theory

   III. Applications

   References

10. Novel Structural Studies in Solution

    I. Introduction

    II. Ion Pairing in Solution

    III. Orbital Ground State Symmetry

    References

11. Biological Applications

    I. Introduction

    II. PMR Characteristics of Proteins

    III. Contact Shifts Induced by Extrinsic Ions

    IV. Heme Proteins

    V. Iron-Sulfur Proteins

    VI. Conclusions

    References

12. Lanthanide Shift Reagents and Other Analytical Applications

    I. Introduction

    II. Lanthanide Shift Reagents

    III. Spin Decoupling and Relaxation Enhancement

    IV. Determination of Relative Stability Constants

    References

13. Lanthanide and Actinide Complexes

    I. Introduction

    II. Important General Features of the Electronic Structure of fn Systems

    III. Experimental Results

    IV. The Origin of the Pure Fermi Contact Contributions

    References

14. Nuclei Other Than Protons

    I. Introduction-Scope and General Overview

    II. Distinctive Features of Heteronuclear NMR

    III. Survey of Experimental Results

    Appendix

    References

15. NMR Studies of Organic Radicals

    I. Introduction

    II. Kinetics of Reactions Involving Diamagnetic and Paramagnetic Molecules

    III. Hyperfine Coupling Constants from NMR Spectra

    IV. NMR of Polyradicals

    V. Radical-Solvent Interactions

    References

16. Some Notes Added in Proof

    I. Introduction

    II. Analysis of Isotropic Shifts

    III. Stereochemistry

    IV. Intramolecular Rearrangements

    V. Biological Applications

    VI. Shift Reagents and Analytical Applications

    VII. Deuterium NMR

    References

Author Index

Subject Index