Dynamic Nuclear Magnetic Resonance Spectroscopy

Dynamic Nuclear Magnetic Resonance Spectroscopy provides an overview of the state of knowledge in dynamic nuclear magnetic resonance (DNMR) spectroscopy. The early chapters describe the theoretical basis and practical techniques which have or will be used for extracting kinetic data from DNMR spectra. The subsequent chapters provide reviews of the many areas in which DNMR spectroscopy has been applied.

Key topics covered include nuclear exchange processes; band-shape analysis; application of nonselective pulsed NMR experiments: diffusion and chemical exchange; spin-spin relaxation time determination; rotation about single and double bonds in organic molecules; and dynamic molecular processes in inorganic and organometallic compounds. Also discussed are studies on stereochemical nonrigidity in organometallic and metal carbonyl compounds; fluxional allyl complexes; carbonium ion rearrangements; and proton transfer processes. It is hoped that this volume will provide a literature guide, source book, and progress report which will be helpful to all those who will continue or will begin work in this field.

Contenu

List of Contributors

Preface

1 Time-Dependent Magnetic Perturbations

I. Background

II. Dipole-Dipole Interactions

III. Chemical Exchange

IV. Coherent Time-Dependent Fields

V. Accomplishments and Prospects

References

2 Delineation of Nuclear Exchange Processes

I. Introduction

II. Dynamic Stereochemistry of Symmetric Molecules

III. NMR Differentiable Reactions

IV. Examples

References

3 Band-Shape Analysis

I. Introduction

II. Classical Theory

III. Quantum-Mechanical Theory

IV. Practical Band-Shape Analysis

V. Treatment of Dynamic Data

VI. Conclusion

References

4 Application of Nonselective Pulsed NMR Experiments-Diffusion and Chemical Exchange

I. Introduction

II. Diffusion and Flow

III. Chemical Exchange Rates from Spin-Echo Studies

IV. Chemical Exchange Rates from Rotating Frame Relaxation

References

5 Determination of Spin-Spin Relaxation Times in High-Resolution NMR

I. Introduction

II. Definitions

III. Experimental Methods

IV. Concluding Remarks

References

6 Rotation about Single Bonds in Organic Molecules

I. Introduction

II. Rotation about sp3-sp3 Carbon-Carbon Single Bonds

III. Rotation about sp3-sp2 Carbon-Carbon Single Bonds

IV. Rotation about sp2-sp2 Carbon-Carbon Single Bonds

V. Rotation about Carbon-Nitrogen Single Bonds

VI. Rotation about Miscellaneous Single Bonds

References

7 Rotation about Partial Double Bonds in Organic Molecules

I. Introduction

II. Amides and Related Systems (R1R2N-COX)

III. Amidines, Thionamides, Selenamides, and Related Compounds [R-C(=X)-N

IV. Enamines

V. Enolates, Enol Ethers and Thio Enol Ethers, Acylides, Diazoketones, and Aminoboranes

VI. Potentially Aromatic Systems

VII. Cumulenes

VIII. Inversion versus Rotation-Imines and Related Systems

References

8 Dynamic Molecular Processes in Inorganic and Organometallic Compounds

I. Introduction

II. Recent Advances in Instrumentation and Technique

III. Applications

IV. Conclusion

References

9 Stereochemically Nonrigid Metal Chelate Complexes

List of Abbreviations

I. Introduction

II. Four-Coordinate Systems

III. Six-Coordinate Systems

IV. Systems of Higher Coordination Number

V. Summary

References

10 Stereochemical Nonrigidity in Organometallic Compounds

Introduction

I. Cyclopolyenylmetal Systems

II. Cyclopolyenemetal Systems

III. Systems with Two Independent Metal Atoms on One Ring

IV. Scrambling of Differently Bonded Rings

V. Fluxionality in the Solid State

VI. Miscellaneous Systems

VII. Some Nonfluxional Molecules, or the Dog in the Night-Time

References

11 Fluxional Allyl Complexes

I. Introduction

II. Bonding and Movements of the Allyl Group in Metal-Allyl Compounds

III. Survey of Reactions Occurring for Metal-p-Allyl Compounds

IV. Fluxional Metal-s-Allyl and Ionic Metal-Allyl Compounds

V. Concluding Remarks

References

12 Stereochemical Nonrigidity in Metal Carbonyl Compounds

I. Introduction

II. Permutational and Geometrical Isomerizations

III. Bridge-Terminal Exchanges and Scrambling of CO Groups

Note Added in Proof

References

13 Dynamic NMR Studies of Carbonium Ion Rearrangements

I. Introduction

II. Generation of Stable Carbonium Ion Solutions

III. Types of Carbonium Ion Rearrangements Studied

References

14 Conformational Processes in Rings

I. Introduction

II. Definitions of Conformational Processes

III. Conformational Energy Calculations

IV. Experimental Data and General Discussion

References

15 Proton Transfer Processes

I. Introduction

II. Rate of Proton Exchange

III. Kinetic Analysis

IV. Comparison with Relaxation Methods

V. Representative Results and Conclusions

VI. Concluding Remarks

References

Subject Index